Patent Publication Number: US-2013235278-A1

Title: Liquid crystal panel, liquid crystal display device, television device, and method of manufacturing liquid crystal panel

Description:
TECHNICAL FIELD 
     The present invention relates to a liquid crystal panel, a liquid crystal display device, and a television device, and a method of manufacturing a liquid crystal panel. 
     BACKGROUND ART 
     One of known methods of manufacturing a liquid crystal panel is described below. Switching components (e.g., TFTs) and pixel electrodes are arranged on one of a pair of glass substrates. Counter electrodes are arranged on the other one of the pair of glass substrates. Thereafter, the pair of glass substrates is bonded together with a spacer therebetween. Liquid crystals are injected between the glass substrates to form a liquid crystal layer. Then, polarizing plates are attached to respective outer surfaces of the glass substrates to obtain a liquid crystal panel. 
     Such a manufacturing process of a liquid crystal panel may include a test process that is executed at a predetermined timing for detecting errors. For example, the test process may be executed after the liquid crystal layer is formed, and in such a test process, a pair of test polarizing plates may be arranged to sandwich the glass substrates. Then, a test backlight is turned on to drive switching components. Accordingly, it is checked if any display failures or display errors occur. 
     If the liquid crystal layer includes a foreign obstacle, light that strikes the foreign obstacle may be irregularly reflected by the foreign obstacle in the test process. In such a case, a portion corresponding to the foreign obstacle may be detected as a bright point defect having high brightness even in case of displaying with black. The bright point defect extremely degrades the display quality and deteriorates the yield in production. 
     Patent Document 1 discloses a manufacturing method of a liquid crystal display device in which a bright point defect is corrected by a light blocking material. The liquid crystal panel in the Patent Document 1 includes a pair of glass substrates that seals a liquid crystal layer therebetween. In the manufacturing method, a recess is formed on at least one of the glass substrates. The recess is formed on a surface of the one glass substrate opposite from a surface facing the liquid crystal layer, and corresponding to a pixel in which the bright point defect occurs. Then, the recess is filled with a light blocking material. The light blocking material blocks light exiting from the bright point defective area, or blocks light exited from a backlight so that the light does not reach a foreign obstacle in the liquid crystal layer. Accordingly, the bright point defective area is displayed in black, and this corrects the bright point defect. 
     Patent Document 2 discloses a method of correcting a bright point defect in a display device by blackening pixels in which the bright point defect occurs. In the method, a laser irradiates a color filter corresponding to a pixel having the bright point defect. The laser irradiates the color filter from an outer surface of a glass substrate. Accordingly, a part of the color filter is decomposed and a space is formed therein. Next, a laser irradiates a black matrix arranged around effective pixels and this diffuses the black matrix into the space and blackens the space. Accordingly, the bright point defect area is displayed in black. This corrects the bright point defect. 
     RELATED ART DOCUMENT 
     Patent Document 
     
         
         Patent Document 1: Japanese Unexamined Patent Application Publication No. 05-210074 
         Patent Document 2: Japanese Unexamined Patent Application Publication No. 2006-227621 
       
    
     Problem to be Solved by the Invention 
     With the method in Patent Document 1, if the point defect area is viewed from an angle, the light emitting from the bright point defect area may not be sufficiently blocked by the light blocking material and the light emitting from the bright point defect area may leak therefrom. With the method in Patent Document 2, a large amount of black matrix is required to correct the bright point defect area. Therefore, this method is not applicable to correct the bright point defect occurring in a large area. Namely, a size of correctable area is limited. This method also requires a long time to correct the bright point defect because it is difficult to diffuse the black matrix evenly into the space. 
     Disclosure of the Present Invention 
     This invention was made in view of the above problems. An object of this invention is to provide a method of manufacturing a liquid crystal panel in which a bright point defect is effectively corrected. Another object of this invention is to provide a liquid crystal panel in which a bright point defect is effectively corrected. 
     Means for Solving the Problem 
     Technologies described herein are related to a method of manufacturing a liquid crystal panel. The method of manufacturing a liquid crystal panel includes a pair of substrates and a liquid crystal layer provided between the pair of the substrates. The method includes the method comprising: detecting a bright point defect in the liquid crystal panel; forming a first light blocking portion in one of the substrates and in at least a part of a bright point defect area of the substrate, the bright point defect area surrounding the bright point defect with a plan view; forming a recess in a portion of one of the substrates so as to overlap the bright point defect, the recess being formed on a surface of the substrate that is opposite from a surface facing the liquid crystal layer; and forming a second light blocking portion in the recess. 
     According to the above method, the first light blocking portion is formed and accordingly, oblique rays of light exiting from the bright point defect area are less likely to leak therefrom. The second light blocking portion is formed and this blocks direct rays of light exiting from the bright point defect area that are recognized when viewed from the front of the bright point defect. The first light blocking portion and the second light blocking portion are formed and accordingly, the liquid crystal panel in which the bright point defect is effectively corrected is manufactured. 
     The first light blocking portion may be formed in a loop so as to surround the bright point defect with a plan view. 
     According to the above method, the oblique rays of light exiting from the bright point defect area are less likely to leak therefrom by the first light blocking portion. This achieves the liquid crystal panel in which the bright point defect is effectively corrected. 
     The first light blocking portion may be formed by blackening the part of the substrate. 
     The above method achieves the liquid crystal panel in which the light from the bright point defect area is effectively blocked by the first light blocking portion. 
     The part of the substrate may be blackened by diffusing a black matrix to the part of the substrate. 
     According to the above method, the part of the substrate is effectively blackened. 
     The part of the substrate may be blackened by irradiating the part of the substrate with a laser and carbonizing the part of the substrate. 
     According to the above method, the part of the substrate is effectively blackened. 
     The first light blocking portion may be only formed in a portion of the bright point defect area surrounding the bright point defect with a plan view, the portion overlapping one of a yellow pixel and a green pixel. 
     The bright point defect that occur in the portion overlapping one of the yellow pixel and the green pixel is easily recognized when viewed from the front side, whereas the bright point defect that occur in the portion overlapping one of the red pixel and the blue pixel is less likely to be recognized. Namely, the bright point defects that occur in the portion overlapping the red pixel and the blue pixel are unnoticeable without being corrected. According to the above method, the first light blocking portion is only formed in the portion overlapping one of the green pixel and the yellow pixel, and thus the first light blocking portion can be easily formed. 
     In forming the second light blocking potion, the second light blocking portion may be formed such that a part of the second light blocking portion and a part of the first light blocking portion overlap each other. 
     According to the above method, the oblique rays of light exiting from the bright point defect area are less likely to leak therefrom by the first and the second light blocking portions. This achieves the liquid crystal panel in which the bright point defect is effectively corrected. 
     In forming the second light blocking potion, the second light blocking portion may be formed by filling the recess with a light blocking material. 
     According to the above method, the second light blocking portion is effectively formed. 
     In forming the second light blocking potion, the light blocking material may be black lacquer. 
     According to the above method, the liquid crystal panel in which the light from the bright point defect area is effectively blocked by the second light blocking portion is manufactured. 
     In forming the second light blocking potion, the light blocking material may be filled into the recess so as to be flattened at an opening surface of the recess. 
     According to the above method, the liquid crystal panel in which the light from the bright point defect area is effectively blocked by the second light blocking portion is manufactured. 
     In forming the recess, the recess may be formed by drilling a part of the substrate using a drill. 
     According to the above method, the recess is effectively formed. 
     In forming the recess, the recess may be formed to have a depth greater than a half of a thickness of the substrate. 
     According to the above method, a light blocking property of the second light blocking portion that is formed in the recess is enhanced. 
     Another aspect of the technologies described herein relates to a liquid crystal panel including a pair of substrates, a liquid crystal layer, a first light blocking portion, a recess, and a second light blocking portion. The liquid crystal layer is provided between the pair of substrates. The first light blocking portion is formed in one of the substrates. The first light blocking portion is formed in apart of an area that surrounds a bright point defect of the substrate with a plan view. The recess is formed in a portion of one of the substrates that overlaps the bright point defect, and the recess is formed on a surface of the one substrate opposite from a surface facing the liquid crystal layer. The second light blocking portion is formed in the recess. 
     According to the above method, the first and second light blocking portions block light exiting from the bright point defect area. This achieves the liquid crystal panel in which the bright point defect is effectively corrected. 
     The technology disclosed herein is applicable to a liquid crystal display device including the above mentioned liquid crystal panel. A television device including the above liquid crystal display device is also available. The liquid crystal display device and the television device can achieve larger display areas with the above technology. 
     Advantageous Effect of the Invention 
     According to the technology disclosed herein, a liquid crystal panel in which a bright point defect is corrected is manufactured. Further, a liquid crystal panel in which a bright point defect is corrected is achieved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view illustrating a general configuration of a television device TV according to a first embodiment of this invention. 
         FIG. 2  is an exploded perspective view of a liquid crystal display device  10 . 
         FIG. 3  is a schematic cross-sectional view of the liquid crystal display device  10 . 
         FIG. 4  is a magnified cross-sectional view of a test liquid crystal panel  11   a  before a bright point defect is corrected. 
         FIG. 5  is a cross-sectional view of the test liquid crystal panel  11   a  during a process of detecting a bright point defect in the test liquid crystal panel  11   a.    
         FIG. 6  is a magnified cross-sectional view illustrating a part of a liquid crystal panel  11  during a process (1) of manufacturing the liquid crystal panel  11 . 
         FIG. 7  is a plan view illustrating a part of the liquid crystal panel  11  during the process (1) of manufacturing the liquid crystal panel  11 . 
         FIG. 8  is a magnified cross-sectional view illustrating a part of the liquid crystal panel  11  during a process (2) of manufacturing the liquid crystal panel  11 . 
         FIG. 9  is a plan view illustrating a part of the liquid crystal panel  11  during the process (2) of manufacturing the liquid crystal panel  11 . 
         FIG. 10  is a magnified cross-sectional view illustrating a part of the liquid crystal panel  11  during a process (3) of manufacturing the liquid crystal panel  11 . 
         FIG. 11  is a magnified cross-sectional view illustrating a part of the liquid crystal panel  11  during a process (4) of manufacturing the liquid crystal panel  11 . 
         FIG. 12  is a plan view illustrating a part of the liquid crystal panel  11  during the process (4) of manufacturing the liquid crystal panel  11 . 
         FIG. 13  is a magnified cross-sectional view of the liquid crystal panel  11 . 
         FIG. 14  is a magnified cross-sectional view illustrating a part of a liquid crystal panel  111  during a process (1) of manufacturing the liquid crystal panel  111  according to a second embodiment. 
         FIG. 15  is a plan view illustrating a part of the liquid crystal panel  111  during the process (1) of manufacturing the liquid crystal panel  111  according to the second embodiment. 
         FIG. 16  is a magnified cross-sectional view illustrating a part of a liquid crystal panel  211  according to a third embodiment. 
         FIG. 17  is a plan view illustrating a part of ea liquid crystal panel during a process (1) of manufacturing a liquid crystal panel according to a fourth embodiment. 
         FIG. 18  is a plan view illustrating a part of the liquid crystal panel during a process (2) of manufacturing the liquid crystal panel according to the fourth embodiment. 
         FIG. 19  is a plan view illustrating a part of a liquid crystal panel during a process (1) of manufacturing a liquid crystal panel according to a fifth embodiment. 
         FIG. 20  is a plan view illustrating a part of the liquid crystal panel during a process (2) of manufacturing the liquid crystal panel according to the fifth embodiment. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     First Embodiment 
     A first embodiment will be described with reference to the drawings. An X-axis, a Y-axis, and a Z-axis are illustrated in a part of each drawing. Directions indicated by the axes in each drawing correspond to directions indicated by the respective axes in other drawings. A Y-axis direction corresponds to a vertical direction and an X-axis direction corresponds to a horizontal direction. 
       FIG. 1  illustrates a television device TV according to the first embodiment in an exploded perspective view. As illustrated in  FIG. 1 , the television device TV includes a liquid crystal display  10 , front and back cabinets Ca and Cb which house the liquid crystal display device  10  therebetween, a power supply P, a tuner T, and a stand S. The liquid crystal display device  10  has a landscape rectangular shape as a whole and held in the vertical position. 
       FIG. 2  illustrates the liquid crystal display device  10  in an exploded perspective view.  FIG. 3  illustrates the liquid crystal display device  10  in a schematic cross-sectional view taken along the Y-axis direction. An upper side in each of  FIG. 2  and  FIG. 3  corresponds to a front side, and a lower side therein corresponds to a rear side. As illustrated in  FIG. 2  and  FIG. 3 , the liquid crystal display device  10  includes a liquid crystal panel  11  as a display panel, and a backlight unit  12  as an external light source. A frame-shaped bezel  13  integrally holds the liquid crystal panel  11  and the backlight unit  12 . The backlight unit  12  is a direct type backlight unit, and includes a plurality of light sources (cold cathode tubes  17 , which are high-pressure discharge tubes, are used in the embodiment). The light sources are arranged behind and along a panel surface (i.e., display surface) of the liquid crystal panel  11 . The liquid crystal panel  11  will be explained later. 
     As illustrated in  FIG. 2  and  FIG. 3 , the backlight unit  12  includes a chassis  14 , an optical member  15 , and a frame  16 . The chassis  14  is made of metal such as aluminum. The chassis  14  has a box-like shape having an opening on its upper side. The optical member  15  is arranged on the backlight chassis  14  so as to cover the opening thereof. The frame  16  has a frame-like shape and holds the optical member  15 . 
     The chassis  14  houses a plurality of cold cathode tubes  17 , holders  18 , lamp holders  19 , lamp clips  20 , and a reflection sheet  14   a . The reflection sheet  14   a  is illustrated in  FIG. 3 , and not illustrated in  FIG. 2 . Each of the cold cathode tubes  17  has an elongated tubular shape. Each of the plurality of cold cathode tubes  17  (eighteen cold cathode tubes  17  in total in  FIG. 2 ) is housed in the chassis  14  such that a longitudinal direction (i.e., axial direction) thereof matches a longitudinal direction of the chassis  14 . The holders  18  are made of rubber. The holders  18  hold ends of the cold cathode tubes  17 . The lamp holders  19  cover a group of the cold cathode tubes  17  and a group of the holders  18 . Each of the lamp clips  20  is made of a synthetic resin, and has a clip-like shape. The lamp clips  20  fix the cold cathode tubes  17  to the chassis  14 . The reflection sheet  14   a  is made of a resin sheet having light reflectivity. The reflection sheet  14   a  is arranged along an inner surface of the chassis  14 . The reflection sheet  14   a  reflects light emitted from the cold cathode tubes  17  toward an optical member  15  side (light exit side). In the backlight unit  12 , a light exit side of the backlight unit  12  is a side closer to the optical member  15  than the cold cathode tubes  17 . 
     The optical member  15  is made of a synthetic resin having a light blocking property, and has a plan-view rectangular shape. The optical member  15  is arranged between the cold cathode tubes  17  and the liquid crystal panel  11 . The optical member  15  may include a diffuser plate, a diffuser sheet, a lens sheet, and a brightness enhancing sheet in this sequence from the rear side. The optical member  15  converts liner light emitted from the cold cathode tubes  17  into uniform planar light. 
     Next, the liquid crystal panel  11  will be explained.  FIG. 13  illustrates a magnified cross-sectional view of the liquid crystal panel  11 . The liquid crystal panel  11 , as illustrated in  FIG. 13 , includes a pair of boards  30  and  40 . The pair of boards  30  and  40  is bonded together with a predetermined gap therebetween. Liquid crystals are sealed between the boards  30  and  40 , forming a liquid crystal layer  50 . 
     The board  30  includes a glass substrate  31 , TFTs (Thin Film Transistor)  32 , pixel electrodes  33 , and an alignment film  34 . The TFTs  32  are semiconductor components and arranged on a side of the glass substrate  31  close to the liquid crystal layer  50 . The pixel electrodes  33  are electrically connected to the TFTs  32 . The alignment film  34  is arranged on a side of the TFTs  32  and the pixel electrodes  33  close to the liquid crystal layer  50 . The board  30  (or the glass substrate  31 ) of the pair of boards  30  and  40  is arranged adjacent to the backlight unit  12 . 
     The board  40  is an opposing board including a glass substrate  41 , color filter  42 , counter electrodes  43 , and an alignment film  44 . The color filter  42  is arranged on a side of the glass substrate  41  close to the liquid crystal layer  50 . The color filter  42  has colored sections such as R (red), G (green), B (blue) sections (an example of picture elements) arranged in a predetermined pattern. A black matrix BM is arranged between the colored sections. The counter electrodes  43  are arranged on a side of the color filter  42  close to the liquid crystal layer  50 . The alignment film  44  is arranged on a side of the counter electrodes  43  facing the liquid crystal layer  50 . A polarizing plate  45  is provided on a side of the glass substrate  41  away from the liquid crystal layer  50 . 
     The liquid crystal panel  11  in  FIG. 13  includes a foreign obstacle X 1 , which may cause a bright point defect, in the liquid crystal layer  50 . The liquid crystal panel  11  also includes a light blocking means for blocking light exiting from a portion of the liquid crystal layer  50  including the foreign obstacle X 1 . Thus, the bright point defect is corrected in the liquid crystal panel  11 . In the present embodiment, the foreign obstacle X 1  is included in a portion of the liquid crystal layer  50  overlapping the colored section B (blue) of the color filter  42  in  FIG. 4  (hereinafter, referred to as a colored section B to be corrected). 
     The light blocking means for blocking light exiting from a portion of the liquid crystal layer  50  including the foreign obstacle X 1  will be explained. The light blocking means is provided in the liquid crystal panel  11 . A first light blocking portion BL 1  is formed in apart of the color filter  42  in the liquid crystal panel  11  to surround the foreign obstacle X 1  in a loop shape with a plan view. The first light blocking portion BL 1  is black and blocks light. A second light blocking portion BL 2  is formed in a part of the glass substrate that is provided on the front side (light exit side) of the liquid crystal panel  11 . The second light blocking portion BL 2  overlaps the foreign obstacle X 1  with a plan view. The second light blocking portion BL 2  is also black and blocks light. The first light blocking portion BL 1  blocks rays of light that causes a bright point defect due to the foreign obstacle X 1 . Thus, the bright point defect is not recognized when the area overlapping the foreign obstacle X 1  is viewed from the front side (light exit side) of the liquid crystal panel  11 . Further, the first light blocking portion BL 1  blocks oblique rays of light that causes the bright point defect due to the foreign obstacle X 1 . Thus, the bright point defect is not recognized when the area overlapping the foreign obstacle X 1  is viewed from an angled front side (light exit side) of the liquid crystal panel  11 . Accordingly, the light reflecting off the foreign obstacle X 1  is effectively blocked in the area of the liquid crystal panel  11  where the foreign obstacle X 1  exists. The following will describe the method of manufacturing the liquid crystal panel  11  in which the bright point defect is corrected. 
     First, to detect a portion in which a bright point defect is caused, a process for detecting a bright point defect is performed. A liquid crystal panel in a manufacturing process is referred to as a test liquid crystal panel  11   a  hereinafter.  FIG. 4  is a magnified cross-sectional view of the test liquid crystal panel  11   a  before correcting the bright point defect.  FIG. 5  is a cross-sectional view of the test liquid crystal panel  11   a  during a process for detecting a bright point defect in the test liquid crystal panel  11   a . The test liquid crystal panel  11   a  in  FIG. 4  does not include polarizing plates  35 ,  45 . The test liquid crystal panel  11   a  is a liquid crystal panel before the polarizing plates  35 ,  45  are arranged on surfaces of the glass substrates  31 ,  41 . Namely, the surfaces of the glass substrates  31 ,  41  are exposed during the detecting process. 
     In the detecting process, a pair of test polarizing plates  71  are arranged to sandwich the boards  30  and  40  of the test liquid crystal panel  11   a  therebetween. Then, as illustrated in  FIG. 5 , a test backlight  72  is arranged on a rear side of the test liquid crystal panel  11   a , and turned on. The test liquid crystal panel  11   a  is illuminated with light from the test backlight  72  from the rear side thereof. Wirings arranged on the glass substrate  31  are connected to a test circuit and signals are supplied to each of the wirings from the test circuit to drive the TFTs  32 . Accordingly, the alignment of the liquid crystals included in the liquid crystal layer  50  is controlled to provide a display condition on the test liquid crystal panel  11   a . The display condition is checked by image processing or checked visually by an inspector. 
     In the detection process, a bright point defect that is recognized as a bright dot on a black display may be detected. The foreign obstacle X 1  in the liquid crystal layer  50  irregularly reflects light and this may cause the bright point defect. If such a bright point defect is detected, the bright point defect is corrected through a series of processes for correcting the bright point defect. The processes will be explained later. Possible causes of entrance of the foreign obstacle X 1  in the liquid crystal layer  50  are as follows. The foreign obstacle X 1  may be adhered to surfaces of the boards  30  and  40  facing the liquid crystal layer  50  before providing the liquid crystals in the space between the boards  30  and  40 . The foreign obstacle X 1  may be included in the liquid crystals. 
       FIG. 6  to  FIG. 12  illustrate a process of correcting the bright point defect, namely, a process of manufacturing the liquid crystal panel  11  in which the bright point defect is corrected.  FIG. 6 ,  FIG. 8 ,  FIG. 10 , and  FIG. 11  are cross-sectional views each illustrating a portion of the glass substrate  41  and the color filter  42  adjacent to the colored section B to be corrected. The glass substrate  41  is provided on the front side (light exit side) of the liquid crystal panel  11 .  FIG. 7 ,  FIG. 9 , and  FIG. 12  are plan views seen from the front side each illustrating a portion of the color filter  42  adjacent to the colored section B to be corrected. 
     The bright point defect correcting process includes a first light blocking portion forming process, a recess forming process, and a second light blocking portion forming process. As illustrated in  FIG. 6 , in the first light blocking portion forming process, a portion of a surface of the colored section B to be corrected in the color filter  42  is irradiated with a laser from the front side of the glass substrate  41 . Herein, the laser irradiates a portion of the colored section B to be corrected along the black matrix BM that is formed around the colored section B to be corrected. Accordingly, a trace of laser irradiation is formed in a loop inside and adjacent to the black matrix BM. The part of the colored section B to be corrected that is irradiated with laser is decomposed and this forms a hole H that is a space. The hole H is formed in a loop and inside the black matrix BM that surrounds the colored section B to be corrected in the color filter  42 , as illustrated in  FIG. 7 . Strength of the laser is adjusted not to cause denaturalization in the color filter  42  by changing electric power and pulse frequency. 
     Next, a laser irradiates the black matrix BM adjacent to and outside the hole H as illustrated in  FIG. 8 . This diffuses the black matrix BM into the hole H and fills the hole H with the black matrix BM. The hole H filled with the black matrix BM becomes black. This forms the first light blocking portion BL 1  that blocks light. As illustrated in  FIG. 9 , the first light blocking portion BL 1  is formed in a loop and inside the black matrix MB that surrounds the colored section B to be corrected in the color filter  42 . A series of processes illustrated in  FIG. 7  and  FIG. 9  is performed by laser irradiation from an inner edge side of the loop-shaped hole H toward a black matrix BM side. In the laser irradiation method, the hole H is formed by moving laser, and if the laser reaches the black matrix BM, the black matrix BM is diffused into the hole H. 
     Next, the recess forming process is performed. As illustrated in  FIG. 10 , in the recess forming process, a recess  41   a  having a substantially cylindrical shape is formed in a part of the glass substrate  41  that overlaps the foreign obstacle X 1 . The glass substrate  41  is provided on the front side of the liquid crystal panel  11  and the recess  41   a  is formed on a surface of the glass substrates  41  that is opposite to the liquid crystal layer  50  side surface. The recess  41   a  is formed by drilling the glass substrate  41  with a micro drilling device. The recess  41   a  is formed to have a depth that is greater than a half of a thickness of the glass substrate  41  and so as not to be close to the color filter  42  to maintain the strength of the glass substrate  41 . The recess  41   a  is formed such that an outer periphery of a bottom surface of the recess  41  overlaps apart of the first light blocking portion BL 1  with a plan view. 
     Next, the second light blocking portion forming process is performed. In the second light blocking portion forming process, as illustrated in  FIG. 11 , black lacquer is filled into the recess  41   a  that is formed by the recess forming process. The filling process may be performed by coating the surface of the glass substrate  41  having the recess  41   a  with the black lacquer. Accordingly, the second light blocking portion BL 2  that blocks light is formed inside the recess  41   a . The black lacquer coats and fills the recess  41   a  such that a surface of the filled black lacquer is flat at an opening of the recess  41   a . As illustrated in  FIG. 12 , the second light blocking portion BL 2  that is formed by filing the recess  41   a  with black lacquer overlaps almost an entire area of the colored portion B to be corrected in the color filter  42  and also overlaps a part of the first light blocking portion BL 1  with a plan view. The second light blocking portion BL 2  is formed in substantially a circular shape inside the first light blocking portion BL 1  so as to overlap an entire projection area of the foreign obstacle X 1 . 
     After forming the light blocking portion BL 2 , the polarizing plate  35  is arranged on a surface of the glass substrate  35  that is opposite from the liquid crystal layer  50  side surface. The polarizing plate  45  is arranged on a surface of the glass substrate  41  that is opposite from the liquid crystal layer  50  side. The liquid crystal panel  11  in which the bright point defect is corrected as illustrated in  FIG. 13  is manufactured by the above-mentioned processes. According to the method in the present embodiment, the liquid crystal panel  11  in which the point defect is effectively corrected by the first light blocking portion BL 1  and the second light blocking portion BL 2  is obtained. 
     According to the method of manufacturing the liquid crystal panel  11  of the present embodiment, the first light blocking portion BL 1  is formed in the first light blocking portion forming process, and accordingly oblique rays of light exiting from the bright point defect area are less likely to leak. Also, the second light blocking portion BL 2  that is formed in the second light blocking portion forming process can block direct rays of light exiting from the bright point defect area that are recognized when viewed from the front of the bright point defect. By executing the first and second light blocking portion forming processes, the liquid crystal panel  11  in which the bright point defect is effectively corrected can be obtained. 
     In the recess forming process, the recess is not allowed to have a depth that reaches a portion of the glass substrate  41  close to the liquid crystal layer and also it is difficult to form the recess having a large opening, because it is required to maintain the strength of the glass substrate and surface visibility of the glass substrate. Therefore, the light blocking portion BL 2  cannot block all of the light that is caused by the foreign obstacle X 1 . Thus, oblique rays of light exiting from the bright point defect may leak from the bright point defect area. The method of manufacturing the liquid crystal panel  11  according to the present embodiment provides the first light blocking portion BL 1  as well as the second light blocking portion BL 2 . Accordingly, the oblique rays of light exiting from the bright point defect are less likely to leak from the bright point defect area. Thus, a large bright point defect can be corrected. 
     In the first light blocking portion forming process for diffusing the black matrix BM into the hole H, it is difficult to diffuse the black matrix BM uniformly in the entire hole H. Further, if the hole H is large, a large amount of black matrix BM is required to fill in the hole H, and therefore, the entire hole may not be filled with the black matrix BM. It is also difficult to optimize irradiation conditions of the laser for diffusing the black matrix BM. Therefore, it is difficult to form the light blocking portion BL 1  so as to cover the area that entirely overlaps the foreign obstacle X 1 . Thus, it is difficult for the light blocking portion BL 1  to block the direct rays of light that are recognized when viewed from the front of the bright point defect. According to the method of manufacturing the liquid crystal panel  11  of the present embodiment, the second light blocking portion BL 2  is formed as well as the first light blocking portion BL 1 . With this configuration, the direct rays of light that are recognized when viewed from the front of the bright point defect are blocked. Thus, a large bright point defect can be corrected. Further, the hole H is formed in only the portion of the colored section to be corrected that is inside and adjacent to the black matrix BM. This shortens the time for diffusing the black matrix BM to the hole H in the first light blocking portion forming process. Namely, this also shortens the manufacturing time for the liquid crystal panel  11 . 
     In the method of manufacturing the liquid crystal panel  11  according to the present embodiment, the first light blocking portion BL 1  is formed in a loop so as to surround the bright point defect with a plan view in the first light blocking portion forming process. The oblique rays of light exiting from the bright point defect are less likely to leak from the bright point defect area by the first light blocking portion BL 1 . Thus, the liquid crystal panel  11  in which the bright point defect is effectively corrected is obtained. 
     According to the method of manufacturing the liquid crystal panel  11  of the present embodiment, the first light blocking portion BL 1  is formed by blackening a part of the color filter  42  in the first light blocking portion forming process. Accordingly, the liquid crystal panel  11  in which the light exiting from the bright point defect is effectively blocked by the first light blocking portion BL 1  is obtained. 
     According to the method of manufacturing the liquid crystal panel  11  of the present embodiment, the black matrix BM is diffused to a part of the color filter  42  to blacken the part of the color filter  42  in the first light blocking portion forming process. Thus, the part of the color filter  42  is effectively blackened in the first light blocking portion forming process. 
     In the method of manufacturing the liquid crystal panel  11  according to the present embodiment, the second light blocking portion BL 2  is formed such that apart of the second light blocking portion BL 2  and a part of the first light blocking portion BL 1  overlap in the second light blocking portion forming process. The first light blocking portion BL 1  and the second light blocking portion BL 2  block the light exiting from the bright point defect area and the oblique rays of light are less likely to leak from the bright point defect area. This achieves the liquid crystal panel  11  in which the bright point defect is corrected more effectively. 
     In the method of manufacturing the liquid crystal panel  11  according to the present embodiment, the second light blocking portion BL 2  is formed by filling the recess  41   a  with the light blocking material in the second light blocking portion forming process. According to the method, the second light blocking portion BL 2  is effectively formed in the second light blocking portion forming process. 
     In the method of manufacturing the liquid crystal panel  11  according to the present embodiment, the black lacquer is used as the light blocking material in the second light blocking portion forming process. This achieves the liquid crystal panel  11  in which the light exiting from the bright point defect area is effectively blocked by the second light blocking portion BL 2 . 
     In the method of manufacturing the liquid crystal panel  11  according to the present embodiment, the recess  41   a  is filled with the black lacquer that is used as a light blocking material such that a surface of the black lacquer is flat at an opening surface of the recess  41   a  in the second light blocking portion forming process. This achieves the liquid crystal panel  11  in which the light causing the bright point defect is effectively blocked by the second light blocking portion BL 2 . 
     In the method of manufacturing the liquid crystal panel  11  according to the present embodiment, the recess  41   a  is formed by drilling the glass substrate  41  with a micro drilling device in the recess forming process. Thus, the glass substrate is easily drilled and the recess  41   a  is effectively formed in the recess forming process. 
     In the method of manufacturing the liquid crystal panel  11  according to the present embodiment, the recess  41   a  is formed to have a depth that is greater than a half of a thickness of the glass substrate  41  in the recess forming process. Therefore, the second light blocking portion BL 2  occupies a large area in the part of the glass substrate  41  that overlaps the foreign obstacle X 1  with a plan view. This improves the light blocking effect of the second light blocking portion BL 2  formed in the recess  41   a  in the second blocking portion forming process. 
     In the method of manufacturing the liquid crystal panel  11  according to the present embodiment, the first light blocking portion BL 1  and the second light blocking portion BL 2  block light that may cause the bright point defect. This achieves the liquid crystal panel  11  in which the bright point defect is effectively corrected. 
     Second Embodiment 
     A second embodiment will be described with reference to the drawings.  FIG. 14  is a cross-sectional view illustrating a portion of a glass substrate  141  provided on the front side (light exit side) of the liquid crystal panel and a portion of a color filter  142 , and the portions are adjacent to the colored section B to be corrected.  FIG. 15  is a plan view of a portion of the color filter  142  adjacent to the colored section B to be corrected seen from the front. The second embodiment differs from the first embodiment in the method of blackening a part of the color filter  142  in the light blocking portion forming process. Other structures are same as those of the first embodiment, and thus configurations, functions, and effects similar to those of the first embodiment will not be explained. In  FIG. 14  and  FIG. 15 , portions indicated by the number obtained by adding 100 to the reference numerals in  FIG. 8  and  FIG. 9  are same as the portions explained in the first embodiment. 
     In the method of manufacturing the liquid crystal panel according to the second embodiment, apart of the color filter  142  is carbonized to be blackened in the first light blocking portion forming process. Specifically, a direct method may be used to form a first blocking portion B 3  as illustrated in  FIG. 14 . In the direct method, a laser irradiates the part of the colored section B of the color filter  142  to be corrected from the front side of the glass substrate  141 . The irradiated part of the color filter  142  is burned to be blackened. This forms the first light blocking portion BL 3 . A laser irradiates a portion of the colored section B to be corrected along the black matrix BM that is formed around the colored section B to be corrected. Accordingly, a trace of laser irradiation is formed in a loop inside and adjacent to the black matrix BM. In the direct method, the intensity of laser is smaller than that of laser used for forming the hole H in the first light blocking portion forming process of the first embodiment. Thus, laser energy required for the direct method is smaller than that for forming the hole H in the color filter in the first light blocking portion forming process of the first embodiment. As illustrated in  FIG. 15 , the first light blocking portion BL 3  is formed in a loop inside the black matrix BM that surrounds the colored section B of the color filter  42  to be corrected with a plan view. In the method of manufacturing the liquid crystal panel according to the second embodiment, the first light blocking portion BL 3  formed as described above and accordingly, a part of the color filter  142  is directly blackened without forming the hole H in the first light blocking portion forming process. Thus, a part of the color filter  142  is effectively blackened in the first light blocking portion forming process. 
     Third Embodiment 
     A third embodiment will be described with reference to the drawings.  FIG. 16  is a magnified cross-sectional view of a liquid crystal panel  211  according to the third embodiment. The second embodiment differs from the first embodiment in the position of the second light blocking portion BL 2 . Other structures are same as those of the first embodiment, and thus configurations, functions, and effects similar to those of the first embodiment will not be explained. In  FIG. 16 , portions indicated by the number obtained by adding 200 to the reference numerals in  FIG. 13  are same as the portions explained in the first embodiment. 
     In the liquid crystal panel  211  according to the third embodiment, the second light blocking portion BL 2  is formed in the glass substrate  41  that is on the rear side. The second light blocking portion BL 2  is formed in a portion of the glass substrate  41  that overlaps the foreign obstacle X 1  and on a surface of the glass substrate  41  that is away from a liquid crystal layer  250 . The second light blocking portion BL 2  may be formed on the glass substrate  241  provided on the rear side by performing similar processes as the recess forming process and the second light blocking portion forming process described in the first embodiment. In the liquid crystal panel  211  according to the third embodiment, the second light blocking portion BL 2  blocks light from the backlight unit and thus the light does not reach the foreign obstacle X 1 . Thus, the bright point defect is not recognized when the portion of the liquid crystal panel overlapping the foreign obstacle X 1  is viewed from the front of the foreign obstacle X 1  from a front side (light exit side) of the liquid crystal panel  211 . Thus, according to the liquid crystal panel  211  of the third embodiment, the first light blocking portion BL 1  and the second light blocking portion BL 2  block light that causes the bright point defect. This achieves the liquid crystal panel  211  in which the bright point defect is effectively corrected. 
     Fourth Embodiment 
     A fourth embodiment will be described with reference to the drawings. Each of  FIG. 17  and  FIG. 18  is a plan view of a part of the color filter adjacent to a colored section G in liquid crystal panel according to the fourth embodiment. The fourth embodiment differs from the first embodiment in an area in which a foreign substrate X 2  is included and an area in which the first light blocking portion BL 5  is formed. Other structures are same as those of the first embodiment, and thus configurations, functions, and effects similar to those of the first embodiment will not be explained. 
     In the liquid crystal panel according to the fourth embodiment, the liquid crystal layer includes a foreign obstacle X 2 , which may result in a bright point defect, in an area that overlaps the colored sections R, G, and B of the color filter, as illustrated in  FIG. 17 . In the first light blocking portion forming process, a laser irradiates only a part of the colored section G in the area that ranges over the colored sections R, G, B and surrounds the foreign obstacle X 2 . Accordingly, holes are formed in the areas that are irradiated with the laser. The laser then irradiates the black matrix BM adjacent to the areas that are irradiated with the laser and the holes are formed. This diffuses the black matrix BM inside the holes, and thus forms first light blocking portions BL 5 . 
     As illustrated in  FIG. 18 , a second light blocking portion BL 6  is formed so as to cover an entire projection area of the foreign obstacle X 2  in the recess forming process and the second light blocking portion forming process. The second light blocking portion BL 6  has a substantially round shape. The second light blocking portion BL 6  is formed inside the first light blocking portion BL 5 . According to the method of manufacturing the liquid crystal panel in the fourth embodiment, the first light blocking portion BL 5  is only formed in an area overlapping the green colored section G. This simplifies the first light blocking portion forming process. 
     Fifth Embodiment 
     A fifth embodiment will be described with reference to the drawings. A liquid crystal panel according to the fifth embodiment is configured such that a colored section Y (yellow) is arranged between a colored section B and a colored section R of the color filter. Each of  FIG. 19  and  FIG. 20  is a plan view of apart of the color filter of the liquid crystal panel according to the fifth embodiment that is adjacent to the colored section Y. The fifth embodiment differs from the first embodiment in an area of the liquid crystal layer occupied by a foreign substrate X 3  and an area occupied by of the first light blocking portion BL 7 . Other structures are same as those of the first embodiment, and thus configurations, functions, and effects similar to those of the first embodiment will not be explained. 
     In the liquid crystal panel according to the fourth embodiment, the liquid crystal layer includes the foreign obstacle X 3  in a portion that overlaps the colored sections Y and R of the color filter, as illustrated in  FIG. 19 . The foreign obstacle X 3  may cause a bright point defect. The laser irradiates a portion of an area surrounding the foreign obstacle X 3  and ranging over the colored sections Y, R to form a hole. The laser irradiates the black matrix BM adjacent to the area that is irradiated with the laser. This diffuses the black matrix BM into the hole, and thus forms a first light blocking portion BL 7 . 
     As illustrated in  FIG. 20 , a second light blocking portion BL 8  is formed so as to cover an entire projection area of the foreign obstacle X 3  in the recess forming process and the second light blocking portion forming process. The second light blocking portion BL 8  has a substantially round shape. The second light blocking portion BL 8  is formed inside the first light blocking portion BL 7 . According to the method of manufacturing the liquid crystal panel in the fifth embodiment, the first light blocking portion BL 7  is formed only in an area overlapping the yellow colored section Y. This simplifies the first light blocking portion forming process. 
     The above embodiments may be modified in the following forms. 
     (1) In the first embodiment, the second light blocking portion is formed after the first light blocking portion is formed. However, the order of forming the first and second light blocking portions is not limited thereto. The second light blocking portion may be formed prior to forming the first light blocking portion if the first light blocking portion can be formed while the second light blocking portion has been formed. 
     (2) In the above second embodiment, the direct method is used to carbonize a part of the color filter. However, the color filter may be carbonized in other methods. 
     (3) Positions of the first and second light blocking portions are not limited to the above embodiments, and may be suitably changed. 
     (4) In the above embodiments, the television device including the tuner is used. However, the technology can be applied to a display device without a tuner. 
     The embodiments of the present invention are explained in detail above for illustrative propose only, and it is to be understood that the claims are not limited by the forgoing description. The technology described in the claims includes the various modifications of the embodiments described above. 
     The technology components described in the description and the drawings are not required to be used in the combination described in the claims as originally filed. The technology components can show its technical utility when used either alone or in combination. In addition, the technology described in the above description and the drawings can achieve more than one object at the same time, and the technical utility of the technology can be recognized when the technology achieves one of the objects. 
     EXPLANATION OF SYMBOLS 
     TV: television device, Ca, Cb: cabinet, T: tuner, S: stand,  10 : liquid crystal display device,  11 ,  211 : liquid crystal panel,  12 : backlight unit  13 : bezel,  14 : chassis,  15 : optical member,  16 : frame,  17 : cold cathode tube,  18 : holder,  19 : lamp holder,  20 : lamp clip,  30 ,  40 ,  230 ,  240 : board,  31 ,  41 ,  141 ,  231 ,  241 : glass substrate,  42 ,  142 ,  242 : color filter,  32 ,  232 : TFT,  33 ,  233 : pixel electrode,  34 ,  44 ,  234 ,  244 : alignment film,  43 ,  243 : counter electrode,  50 : liquid crystal layer, BL 1 , BL 3 , BL 5 , BL 7 : first light blocking portion, BL 2 , BL 6 , BL 8 : second light blocking portion, BM: black matrix, H: hole, L: laser, X 1 , X 2 , X 3 : foreign obstacle.