News Column

Patent Issued for Liquid Crystal Panel, Liquid Crystal Display Device, Method for Producing Liquid Crystal Panel, and Method for Manufacturing Liquid...

July 30, 2014



Patent Issued for Liquid Crystal Panel, Liquid Crystal Display Device, Method for Producing Liquid Crystal Panel, and Method for Manufacturing Liquid Crystal Display Device

By a News Reporter-Staff News Editor at Journal of Engineering -- A patent by the inventors Makimoto, Shota (Tottori, JP); Misaki, Katsunori (Tottori, JP), filed on November 18, 2010, was published online on July 15, 2014, according to news reporting originating from Alexandria, Virginia, by VerticalNews correspondents.

Patent number 8780312 is assigned to Sharp Kabushiki Kaisha (Osaka, JP).

The following quote was obtained by the news editors from the background information supplied by the inventors: "FIG. 11 is an explanatory view of a conventional liquid crystal panel 101. (a) of FIG. 11 is a plain view of a conventional liquid crystal panel 101 to be used in a liquid crystal display device. (b) of FIG. 11 is a cross-sectional view illustrating a liquid crystal inlet 106 of the conventional liquid crystal panel 101.

"The conventional liquid crystal panel 101 includes (i) a CF substrate 102, made from glass, on which a CF (Color Filter) is to be formed, (ii) a TFT substrate 103, made from glass, on which a TFT (Thin Film Transistor) is to be formed, and (iii) a sealing material (sealant) 104 for sealing liquid crystal (see (a) of FIG. 11). The CF substrate 102 and the TFT substrate 103 constitute a substrate assembly 109 (later described). Liquid crystal is injected through the liquid crystal inlet 106 into a region 105 which is sandwiched between the CF substrate 102 and the TFT substrate 103 and surrounded by the sealing material 104, so that the liquid crystal panel 101 is produced.

"The liquid crystal inlet 106 of the liquid crystal panel 101 is formed between the CF substrate 102 and the TFT substrate 103, and formed so as to be sandwiched between two sealing materials 104 (see (b) of FIG. 11).

"A process for producing the liquid crystal panel 101 includes a substrate assembly forming process and a substrate assembly cutting process. The substrate assembly forming process is a process for forming the substrate assembly 109 by bonding the CF substrate 102 and the TFT substrate 103 to each other such that the sealing material 104 is sandwiched between the CF substrate 102 and the TFT substrate 103. The substrate assembly cutting process is a process for scribing (cutting) the substrate assembly 109 after the substrate assembly forming process. First, the substrate assembly forming process will be described below with reference to (a) through (f) of FIG. 12.

"FIG. 12 is an explanatory view of production of a conventional liquid crystal panel 101. (a) through (f) of FIG. 12 are explanatory views of a process for producing the conventional liquid crystal panel 101. According to the process illustrated in FIG. 12, a sealing material 104 is drawn (formed) on a CF substrate 102. Note, however, that the sealing material 104 can be drawn (formed) on a TFT substrate 103 instead of the CF substrate 102.

"(a) of FIG. 12 is a plain view illustrating the CF substrate 102 onto which the sealing material 104 is to be drawn. (b) of FIG. 12 is a cross-sectional view taken along P-P' line of (a) of FIG. 12. A sealing material draw line 107 is formed on the CF substrate 102 illustrated in (a) of FIG. 12. A draw nozzle 108 draws the sealing material 104 along the sealing material draw line 107. In (a) of FIG. 12, the sealing material 104 has not been drawn yet, and therefore the sealing material 104 has not been shown in the P-P' line cross-sectional view of (b) of FIG. 12.

" of FIG. 12 is a plain view illustrating the CF substrate 102 onto which the sealing material 104 is being drawn. (d) of FIG. 12 is a cross-sectional view taken along P-P' line of of FIG. 12. The draw nozzle 108 draws the sealing material 104, for example, from a start edge 107a of the sealing material draw line 107 to an end edge 107b of the sealing material draw line 107. The P-P' line cross-sectional view of (d) of FIG. 12 illustrates the sealing material 104 which is closer to P than P'.

"(e) of FIG. 12 is a plain view illustrating a substrate assembly 109 in which the CF substrate 102 onto which the sealing material 104 has been drawn, and the TFT substrate 103 are bonded to each other. (f) of FIG. 12 is a cross-sectional view taken along a CF substrate/TFT substrate scribing line 112 of (e) of FIG. 12. The TFT substrate 103, and the CF substrate 102 onto which the draw nozzle 108 has drawn the sealing material 104 from the start edge 107a to the end edge 107b, are bonded to each other so as to form the substrate assembly 109. The P-P' line cross-sectional view of (f) of FIG. 12 illustrates the sealing material 104 which is closer to P than P', and the sealing material 104 which is closer to P' than P.

"The following describes the substrate assembly cutting process with reference to (e) and (f) of FIG. 12. The substrate assembly 109 illustrated in (e) and (f) of FIG. 12 is scribed by use of a diamond cutter (glass cutter) 110. Specifically, the diamond cutter 110 scribes the CF substrate 102 and the TFT substrate 103 along CF substrate/TFT substrate scribing lines 111 through 113 illustrated in (e) of FIG. 12. Further, the diamond cutter 110 scribes the CF substrate 102 along a CF substrate scribing line 114 illustrated in (e) of FIG. 12, and scribes the TFT substrate 103 along a TFT substrate scribing line 115 illustrated in (e) of FIG. 12. Thereafter, liquid crystal is injected through a liquid crystal inlet 106 into a region 105 surrounded by the sealing material 104, so that the liquid crystal panel 101 illustrated in (a) of FIG. 11 is produced.

"Patent Literatures 1 through 4 disclose respective inventions each including a process for scribing a glass substrate in such a manner that the liquid crystal panel 101 is scribed.

"FIG. 13, corresponding to FIG. 4 of Patent Literature 1, is a cross-sectional view illustrating a liquid crystal display panel 116 of Patent Literature 1. Spacers 119' are provided, densely than spacers 119 provided in a display section 118, in a region centering on a scribing line 117, which region extends away by 3 mm from the scribing line 117 on both sides of the scribing line 117. This causes cracks to open vertically when the liquid crystal display panel 116 is scribed, thereby preventing occurrence of a defect caused by glass crack or glass fragment. In FIG. 13, reference numeral 120 represents a sealing material, and reference numerals 121 and 122 represent respective glass substrates.

"FIG. 14, corresponding to FIG. 1 of Patent Literature 2, is a cross-sectional view illustrating a liquid crystal display element 123 of Patent Literature 2. The liquid crystal display element 123 includes (i) a pair of an upper glass substrate 124 and a lower glass substrate 125, (ii) a sealing material 127 for forming a display region 126 between the pair of the upper glass substrate 124 and the lower glass substrate 125, (iii) first pillar spacers 128 for keeping a thickness of a liquid crystal layer uniform in the display region 126, and (iv) second pillar spacers 128 provided, outside the display region 126, between the pair of the upper glass substrate 124 and the lower glass substrate 125. The pair of the upper glass substrate 124 and the lower glass substrate 125 are bonded to each other. Thereafter, a part of the upper glass substrate 124, which part faces a connection terminal 129, is separated from the rest of the upper glass substrate 124.

"Therefore, the second pillar spacers 128 provided outside the display region 126 can prevent an edge member 130 that is a cut part of the upper glass substrate 124 from coming in contact with the lower glass substrate 125, after the part of the upper glass substrate 124 is separated from the rest of the upper glass substrate 124. Therefore, the edge member 130 can be easily removed without its edge damaging the connection terminal 129, by providing the second pillar spacers 128, and it is therefore possible to prevent occurrence of a defect caused by damage to the connection terminal 129. Note that in FIG. 14, reference numeral 131 represents a pixel electrode, reference numeral 132 represents liquid crystal, and reference numeral 133 represents an electrode layer.

"FIG. 15 is an explanatory view of a liquid crystal display device panel of Patent Literature 3. (a) of FIG. 15, corresponding to FIG. 5 of Patent Literature 3, is a view illustrating a liquid crystal display device panel 134 of Patent Literature 3. (b) of FIG. 15, corresponding to FIG. 6 of Patent Literature 3, is an enlarged view of a part circled by a circle 135 illustrated in (a) of FIG. 15.

"A seal line, which formed a liquid crystal inlet 136, is located inside a cut line 137 (see (a) of FIG. 15). A seal line 138, which forms the liquid crystal inlet 136, includes (i) a first line 138a having an opening of the seal line 138 having a square frame shape (ii) second lines 138b, each having a first length, which extend vertically from respective edges of the first line 138a, between which edges the opening is formed, and (iii) third lines 138c, each having a second length, which extend vertically from edges of the respective second lines 138b in respective directions away from the opening so as to be parallel to the cut line 137 (see (b) of FIG. 15).

"In (a) of FIG. 15, reference numeral 139 represents a substrate assembly, and reference numerals 140 through 142 represent respective cut lines. In (b) of FIG. 15, reference numeral 143 represents a sealing material, and reference numeral d represents a gap.

"FIG. 16 is an explanatory view of a liquid crystal display device of Patent Literature 4. (a) of FIG. 16, corresponding to FIG. 1(a) of Patent Literature 4, is a plain view illustrating the liquid crystal display device. (b) of FIG. 16, corresponding to FIG. 1(b) of Patent Literature 4, is a cross-sectional view illustrating the liquid crystal display device.

"As illustrated in (a) and (b) of FIG. 16, transparent electrodes 146 and 147 are formed on upper and lower glass substrates 144 and 145, respectively, and alignment films 148 and 149 are formed on the transparent electrodes 146 and 147, respectively. The alignment films 148 and 149 are subjected to an alignment process. The upper and lower glass substrates 144 and 145 are bonded to each other via a sealing material 150 so as to form a gap serving as a liquid crystal layer 151. A low-adhesive thin film 154 is formed in advance (i) on a region of the upper glass substrate 144, which region faces a projecting part 152 and (ii) where an extended part of the sealing material 150 forms a liquid crystal inlet 153, so that adhesiveness to the sealing material 150 is reduced."

In addition to the background information obtained for this patent, VerticalNews journalists also obtained the inventors' summary information for this patent: "Technical Problem

"In a substrate assembly cutting process (see FIG. 12), a defect such as burr and crack is caused in a part of a sealing material 104, in which part a liquid crystal inlet 106 is formed. The following describes the reason why such a defect is caused.

"A substrate assembly 109 is scribed (a liquid crystal panel 101 is cut out) through the part of the sealing material 104, in which part the liquid crystal inlet 106 is formed. Specifically, a CF substrate 102 and a TFT substrate 103 are scribed along a CF substrate/TFT substrate scribing line 112 (see (e) of FIG. 12).

"The sealing material 104 contains glass fiber so as to have a high hardness, so that the sealing material 104 can control a cell thickness of liquid crystal. Therefore, a diamond cutter 110 applies different pressures to a first part and a second part of a glass substrate (the CF substrate 102 or the TFT substrate 103), onto which first part no sealing material 104 is drawn, onto which second part the sealing material 104 is drawn. This causes the defect such as burr and crack.

"According to an invention of Patent Literature 1, spacers 119 are relatively thinly provided in a display section 118 distant from a scribing line SL than in a region centering on the scribing line SL, which region extends away by 3 mm from the scribing line SL on both sides of the scribing line 117. This causes cracks to open vertically when a liquid crystal display panel 116 is scribed. Therefore, a cross section of the liquid crystal display panel 116 scribed along the scribing line SL becomes sharp.

"According to an invention of Patent Literature 3, in a case where drawing of a sealing material 143 is stopped around a liquid crystal inlet 136, there is a possibility that a seal edge becomes thick, the liquid crystal inlet 136 becomes narrow, and therefore a liquid crystal injection rate is decreased. Not only the seal edge possibly becomes thick but also there is a possibility that the seal edge has a thickness different from a start of drawing of the sealing material 143 to an end of drawing of the sealing material 143, and the seal edge protrudes over a cut line 137. In order to prevent the seal edge from protruding over the cut line 137, the cut line 137 can be formed away from the liquid crystal inlet 136 in advance. This, however, expands a frame. Further, increase in a gap D makes it impossible to inject liquid crystal. Keeping the seal edge away from the liquid crystal inlet 136 (see (b) of FIG. 15) necessitates a space between where liquid crystal is to be sealed to a panel edge, thereby expanding the frame.

"According to an invention of Patent Literature 4, upper and lower glass substrates 144 and 145 are scribed along a scribing line 155 (see (b) of FIG. 16). Therefore, a part where no sealing material 150 is formed, and a part where the sealing material 150 is formed are cut (scribed), as with the liquid crystal panel 101 illustrated in FIG. 11. That is, a glass cutter applies different pressures to the respective parts. This causes a defect such as burr and crack.

"The present invention was made in view of the conventional problems, and an object of the present invention is to provide (i) a liquid crystal panel capable of reducing a defect, such as burr and crack, which is caused during production of a conventional liquid crystal panel, (ii) a liquid crystal display device, (iii) a method for producing the liquid crystal panel, and (iv) a method for producing the liquid crystal display device.

"Solution to Problem

"In order to attain the object, a liquid crystal panel of the present invention is configured to include: a filter substrate on which a color filter is formed; a transistor substrate on which a thin film transistor is formed; a first sealant for sealing liquid crystal injected between the filter substrate and the transistor substrate; a liquid crystal inlet through which the liquid crystal is injected; and first structures being provided between a cut surface among cut surfaces of the liquid crystal panel, on which cut surface the liquid crystal inlet is to be formed, and edges of the first sealant, the first structures each being made from a material from which the color filter is formed or a material from which the thin film transistor is formed.

"In order to attain the object, a method of the present invention for producing a liquid crystal panel is arranged to include the steps of: forming a color filter on a filter substrate; forming a thin film transistor on a transistor substrate; forming first structures, on the filter substrate or the transistor substrate, between a cut surface among cut surfaces of the liquid crystal panel, on which cut surface a liquid crystal inlet is to be formed, and edges of a first sealant; forming, on the filter substrate or the transistor substrate, the first sealant for sealing liquid crystal injected between the filter substrate and the transistor substrate; forming a substrate assembly by bonding the filter substrate and the transistor substrate to each other; and forming the liquid crystal panel by cutting the substrate assembly, the first structures each being made from a material from which the color filter is formed or a material from which the thin film transistor is formed.

"According to the present invention, the first structures, each made from the material from which the color filter is formed or the material from which the thin film transistor is formed, are provided between the cut surface among the cut surfaces of the liquid crystal panel, on which cut surface the liquid crystal inlet is to be formed, and the edges of the first sealant, but no first sealant is provided. This decreases change in pressure to be applied by a cutter during formation of the liquid crystal inlet (during cutting of the substrate assembly), as compared with during production of a conventional liquid crystal panel. Therefore, a defect, such as burr and crack, which is caused during production of the conventional liquid crystal panel, can be reduced. That is, the defect such as burr and crack is further unlikely to be caused, or can be reduced in its size.

"Advantageous Effects of Invention

"A liquid crystal panel of the present invention is a liquid crystal panel, including: a filter substrate on which a color filter is formed; a transistor substrate on which a thin film transistor is formed; a first sealant for sealing liquid crystal injected between the filter substrate and the transistor substrate; a liquid crystal inlet through which the liquid crystal is injected; and first structures being provided between a cut surface among cut surfaces of the liquid crystal panel, on which cut surface the liquid crystal inlet is to be formed, and edges of the first sealant, the first structures each being made from a material from which the color filter is formed or a material from which the thin film transistor is formed.

"A method of the present invention for producing a liquid crystal panel is a method for producing a liquid crystal panel, including the steps of: forming a color filter on a filter substrate; forming a thin film transistor on a transistor substrate; forming first structures, on the filter substrate or the transistor substrate, between a cut surface among cut surfaces of the liquid crystal panel, on which cut surface a liquid crystal inlet is to be formed, and edges of a first sealant; forming, on the filter substrate or the transistor substrate, the first sealant for sealing liquid crystal injected between the filter substrate and the transistor substrate; forming a substrate assembly by bonding the filter substrate and the transistor substrate to each other; and forming the liquid crystal panel by cutting the substrate assembly, the first structures each being made from a material from which the color filter is formed or a material from which the thin film transistor is formed.

"It is therefore possible to provide (i) a liquid crystal panel capable of reducing a defect, such as burr and crack, which is caused during production of a conventional liquid crystal panel, (ii) a liquid crystal display device, (iii) a method for producing the liquid crystal panel, and (iv) a method for producing the liquid crystal display device."

URL and more information on this patent, see: Makimoto, Shota; Misaki, Katsunori. Liquid Crystal Panel, Liquid Crystal Display Device, Method for Producing Liquid Crystal Panel, and Method for Manufacturing Liquid Crystal Display Device. U.S. Patent Number 8780312, filed November 18, 2010, and published online on July 15, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8780312.PN.&OS=PN/8780312RS=PN/8780312

Keywords for this news article include: Sharp Kabushiki Kaisha.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Journal of Engineering


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters