JP4902209B2 - Liquid crystal display panel and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid crystal display panel, and more particularly to a liquid crystal display panel having an alignment film.

  In recent years, with the full-scale advancement of an advanced video and information society and the rapid spread of multimedia systems, the importance of liquid crystal display devices that play a leading role in flat panel displays is increasing. Liquid crystal display devices are widely used as display devices for portable terminal devices because they have the advantages of low power consumption, thinness, and light weight.

  In the conventional liquid crystal display panel, there is a problem that light leakage occurs in the vicinity of the injection port where the alignment film is not provided, and the contrast is lowered. Therefore, a technique for suppressing light leakage by arranging a vertical alignment film at the injection port has been proposed (see, for example, Patent Document 1).

  In recent years, liquid crystal display panels in a VA (Vertically Aligned) mode have been proposed. In a VA mode liquid crystal display panel, a liquid crystal having negative dielectric anisotropy is used, and display is performed by tilting liquid crystal molecules aligned perpendicularly to a substrate by an applied voltage. Compared with the conventional TN (Twisted Nematic) mode liquid crystal display panel, the VA mode liquid crystal display panel has a sharp change in light transmittance with respect to the applied voltage (a sharp threshold characteristic is obtained) and a large contrast ratio. Therefore, high display quality can be obtained.

FIG. 7 shows a configuration of a conventional VA mode liquid crystal display panel 10. As shown in FIG. 7, in the VA mode liquid crystal display panel 10, the liquid crystal molecules 13 are aligned perpendicular to the substrate 11 by the vertical alignment film 12 formed on the substrate 11. However, the vertical alignment film 12 is not formed at the injection port, and the liquid crystal molecules are randomly aligned at the injection port. For this reason, the liquid crystal display panel 10 in the VA mode also has a problem that the light leaks from the injection port portion as in the conventional case and the contrast is lowered. For this reason, as shown in FIG. 8, a vertical alignment film is disposed at the injection port portion to suppress light leakage at the injection port portion.
JP 2000-258784 A

  However, when the vertical alignment film 12 is arranged at the injection port portion, the following problems occur. The polarizing plate 14 attached to the VA mode liquid crystal display panel 10 is arranged in a crossed Nicols state and is normally black. At this time, as shown in FIG. 8, the liquid crystal molecules 13 are aligned perpendicularly to the substrate 11 by the vertical alignment film 12 in the display region and the injection port, and thus have no anisotropy. Therefore, when no voltage is applied, the light transmitted through the polarizing plate 14 on the non-viewing side is transmitted through the liquid crystal layer without changing the polarization state, and thus does not pass through the polarizing plate 14 on the viewing side.

  Further, the sealing material 15 for sealing the injection port and the sealing material (not shown) for fixing both the substrates 11 do not have anisotropy. For this reason, light is not transmitted as described above even in the region where the sealing material 15 and the sealing material are disposed. Therefore, the transmittance of the region where the sealing material 15 and the sealing material are disposed and the region where the vertical alignment film 12 is disposed are substantially equal.

  For this reason, it cannot be confirmed how much the sealing material 15 has been pulled in at the inlet. If the sealing material 15 is excessively drawn and reaches the display area, a display defect occurs. In addition, if the sealing material is not drawn sufficiently, the liquid crystal may leak to the outside.

  The present invention has been made against the background of the above problems, and an object of the present invention is to provide a liquid crystal display panel capable of confirming the amount of sealing material drawn.

  The liquid crystal display panel according to the first aspect of the present invention is a liquid crystal display panel in which liquid crystal is sandwiched between a pair of opposed substrates, and an alignment film provided on the opposing surfaces of the pair of substrates. And a sealing material that is provided in a frame shape so as to surround the display region, and that fixes the pair of substrates, and a sealing material that seals the injection port, and the alignment film Has a projection provided corresponding to the injection port, and the projection is provided with a first window from the distal end to the proximal end of the projection. Thereby, the drawing-in amount of the sealing material can be confirmed.

  The liquid crystal display panel according to the second aspect of the present invention is the above liquid crystal display panel, wherein the alignment film is a vertical alignment film. The present invention is particularly effective in such a case.

  The liquid crystal display panel according to a third aspect of the present invention is the above-described liquid crystal display panel, wherein the first window portion is provided substantially at the center of the inlet. Thereby, it is possible to determine a defective panel in which the sealing material is excessively drawn.

  The liquid crystal display panel according to a fourth aspect of the present invention is the above-described liquid crystal display panel, wherein the width of the first window portion is not more than half of the width of the inlet. Thereby, while reducing the light leakage from a 1st window part, the drawing-in amount of a sealing material can be confirmed easily visually.

  In the liquid crystal display panel according to a fifth aspect of the present invention, in the above liquid crystal display panel, the length of the first window is substantially equal to the length of the protrusion. Thereby, it is possible to determine a defective panel in which the sealing material is excessively drawn.

  The liquid crystal display panel according to a sixth aspect of the present invention is the above-described liquid crystal display panel, wherein the first window portion includes a plurality of openings arranged intermittently. Thereby, the amount of entrainment of the sealing material can be easily confirmed.

  In the liquid crystal display panel according to a seventh aspect of the present invention, in the above liquid crystal display panel, the protrusion is further provided with a second window portion disposed so as to be in contact with the sealing material. The window portion is provided closer to the display area than the second window portion. Thereby, it is possible to easily determine whether or not the sealing material has been pulled in.

  ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal display panel which can confirm the drawing-in amount of a sealing material can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, these figures and description illustrate this invention, and do not restrict | limit the scope of the present invention. It goes without saying that other embodiments may belong to the category of the present invention as long as they are consistent with the present invention.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view showing a configuration of a liquid crystal display panel 100 according to the present embodiment. FIG. 2 is a schematic cross-sectional view showing the configuration of the liquid crystal display panel 100 according to the present embodiment. As shown in FIGS. 1 and 2, the liquid crystal display panel 100 according to this embodiment includes an element substrate 101, a counter substrate 102, a sealing material 103, an injection port 104, a vertical alignment film 105, a protrusion 106, and a sealing material. 107, a window portion 108, a liquid crystal 109, and a polarizing plate 110.

  As shown in FIGS. 1 and 2, the liquid crystal display panel 100 according to the present embodiment has a configuration in which a liquid crystal 109 is sealed between an element substrate 101 and a counter substrate 102 which are arranged to face each other. The element substrate 101 and the counter substrate 102 are rectangular transparent insulating substrates made of glass or the like. The element substrate 101 and the counter substrate 102 are bonded together by a sealing material 103 formed in a rectangular frame shape. A distance between the element substrate 101 and the counter substrate 102 is defined by a spacer (not shown) provided in a region partitioned by the sealing material 103. A liquid crystal 109 is sealed in a region defined by the element substrate 101, the counter substrate 102, and the sealing material 103.

  On the inner surface of the element substrate 101, gate lines (scanning lines) (not shown) are formed in the horizontal direction and source lines (signal lines) (not shown) are formed in the vertical direction, and TFTs are formed near the intersections of the gate lines and the source lines. Is provided. In addition, a plurality of pixel electrodes are formed in a matrix between the gate line and the source line. The gate electrode of the TFT is connected to the gate line, the source electrode is connected to the source line, and the drain electrode is connected to the pixel electrode. A region where the pixel electrode is formed becomes a display region.

  On the other hand, a common electrode (not shown) and color filters of R (red), G (green) and B (blue) are formed on the counter substrate 102. The common electrode is actually a rectangular transparent electrode formed on substantially the entire surface of the counter substrate 102 so as to face the pixel electrode. A transparent conductive film such as ITO (Indium Tin Oxide) is used as the common electrode.

  Further, as shown in FIG. 1, the element substrate 101 is formed so as to extend beyond the counter substrate 102. A drive circuit (not shown) is mounted on the extended portion. Display is performed by applying a voltage between the electrodes provided on the element substrate 101 and the counter substrate 102 to change the arrangement of liquid crystal molecules between the two electrodes and controlling the amount of transmitted light.

  The sealing material 103 is provided in a frame shape so as to surround a display area composed of a plurality of pixel electrodes. An injection port 104 is provided in a part of the sealing material 103. The liquid crystal 109 is injected between the element substrate 101 and the counter substrate 102 through the injection port 104.

  The injection port 104 is sealed with a sealing material 107. As the sealing material 107, a thermosetting resin or a UV curable resin having no anisotropy can be used. The sealing material 107 is not only disposed so as to block the injection port 104 on the side end surfaces of the element substrate 101 and the counter substrate 102, but is drawn from the injection port 104 to between the element substrate 101 and the counter substrate 102. . Thereby, even if the sealing material 107 arranged on the side end face is removed, the liquid crystal 109 is prevented from leaking to the outside by the sealing material 107 drawn between the two substrates.

  As shown in FIG. 2, a vertical alignment film 105 is stacked on the electrodes provided on the element substrate 101 and the counter substrate 102 in a region partitioned by the sealant 103. The vertical alignment film 105 is provided so as to correspond to a display area composed of a plurality of pixel electrodes, and is formed in a substantially rectangular shape. With this vertical alignment film 105, the molecules of the liquid crystal 109 are aligned perpendicularly to the element substrate 101 and the counter substrate 102.

  The vertical alignment film 105 is provided with a protrusion 106 extending from the substantially rectangular vertical alignment film at a position corresponding to the injection port 104. The protrusion 106 is provided to prevent light leakage at the injection port 104 and suppress a decrease in contrast. The protrusion 106 is made of the same vertical alignment film material as that of the vertical alignment film 105. Due to the protrusion 106, the liquid crystal 109 molecules in the injection port 104 are also aligned perpendicularly to the element substrate 101.

  Further, the protrusion 106 of the vertical alignment film 105 is provided with a window 108 extending from the tip of the protrusion 106 toward the base end. The window 108 is formed in a slit shape by cutting out the vertical alignment film material of the protrusion 106. That is, the window part 108 is a part where the vertical alignment film material is not disposed in the protrusion part 106. Therefore, the window 108 does not have a function of preventing light leakage like the protrusion 106, and light incident from the back surface is transmitted. In the slit-shaped window 108, the amount of the sealing material 107 drawn can be confirmed.

  Polarizing plates 110 are attached to the outer surfaces of the element substrate 101 and the counter substrate 102, respectively. The polarizing plate 110 is arranged in a crossed Nicols state so that the absorption axes thereof are orthogonal to each other. As shown in FIG. 2, in the present embodiment, the absorption axis of the counter-viewing side polarizing plate 110 a is arranged in the z direction, and the absorption axis of the viewing side polarizing plate 110 b is arranged in the x direction.

  Here, the light transmission state of each region when no voltage is applied will be described. As described above, in the present embodiment, the absorption axis of the non-viewing-side polarizing plate 110a is disposed in the z direction, and the absorption axis of the viewing-side polarizing plate 110b is disposed in the x direction. Therefore, when the light irradiated from the non-viewing side passes through the anti-viewing side polarizing plate 110a, it becomes linearly polarized light having a vibration direction in the x direction.

  As described above, in the region where the vertical alignment film 105 and the protrusion 106 are formed, the liquid crystal 109 molecules are aligned perpendicular to the element substrate 101. For this reason, the liquid crystal 109 does not have anisotropy, and the linearly polarized light in the x direction incident on the liquid crystal 109 is transmitted as it is and is incident on the viewing side polarizing plate 110b. The linearly polarized light in the x direction incident on the viewing side polarizing plate 110b is absorbed because the absorption axis of the viewing side polarizing plate 110b is arranged in the x direction. For this reason, light does not transmit in the region where the vertical alignment film 105 and the protrusion 106 are formed.

  Here, with reference to FIG. 3, the light transmission state in the region where the sealing material 107 is drawn from the injection port 104 will be described. FIG. 3 is a cross-sectional view showing the configuration of the window 108 of the liquid crystal display panel 100 according to the present invention. As shown in FIG. 3, in the window part 108 where the vertical alignment film material is not formed, the liquid crystal 109 molecules are randomly aligned. For this reason, the liquid crystal 109 of the window 108 has anisotropy, and the polarization state of the linearly polarized light in the x direction incident on the liquid crystal 109 changes. Therefore, the vibration direction component shifted from the absorption axis of the viewing side polarizing plate 110b among the light incident on the viewing side polarizing plate 110b is transmitted. For this reason, light is transmitted through the region of the window portion 108 where the vertical alignment film material is not formed.

  Thus, in the window part 108, the light irradiated from the back surface permeate | transmits. However, a sealing material 107 having no anisotropy is drawn into the part of the injection port 104 between the element substrate 101 and the counter substrate 102 from the injection port 104. For this reason, in the region where the sealing material 107 is drawn, light is not transmitted, similarly to the region where the vertical alignment film 105 and the protrusion 106 are provided. For this reason, a part of the window portion 108 through which light is transmitted is shielded by the sealing material 107. Accordingly, it is possible to confirm the amount of the sealing material 107 drawn in the window portion 108.

  Here, the configuration of the window 108 provided on the protrusion 106 of the vertical alignment film 105 will be described with reference to FIG. As shown in FIG. 4, the window 108 is formed in a slit shape at the approximate center in the width direction of the inlet 104. Further, the window 108 has a length substantially the same as the length of the protrusion 106. That is, the slit-shaped window 108 is formed from the tip of the protrusion 106 to the base end. More specifically, the protrusion 106 is formed from the end of the element substrate 101 to the end of the vertical alignment film 105 corresponding to the display region. That is, the window 108 is formed up to a position corresponding to the inner periphery of the sealing material 103 formed in a frame shape.

  The sealing material 107 has a low compatibility with the sealing material 103 and tends to repel. For this reason, as shown in FIG. 1, the sealing material 107 has the largest amount of pulling in the central portion in the width direction of the injection port 104, and is not pulled much in the vicinity of the sealing material 103.

  Therefore, by forming the window portion 108 substantially at the center in the width direction of the injection port 104 up to the end portion of the vertical alignment film 105, the sealing material 107 is excessively drawn to reach the display region, resulting in a display defect. Can be determined. That is, when the window portion 108 is completely shielded from light by the sealing material 107, it can be determined that the sealing material 107 has reached the display area.

  The width of the window 108 is preferably less than or equal to half the width of the inlet 104. For example, when the width of the inlet 104 is 5 to 10 mm, the width of the window 108 can be set to 1 to 3 mm. Thereby, while suppressing the light leak in the window part 108, the drawing-in amount of the sealing material 107 can be confirmed visually.

  Note that the shape of the window 108 is not limited to the above example. With reference to FIG.5 and FIG.6, the other shape of the window part 108 is demonstrated. 5 and 6 are diagrams showing another example of the shape of the window portion 108. 5 and 6, the same components as those in FIG. 4 are denoted by the same reference numerals.

  As shown in FIG. 5, the window part 108 may be formed from a plurality of openings arranged intermittently. The plurality of openings are arranged from the distal end of the protrusion 106 toward the proximal end. That is, the openings of the plurality of alignment films are arranged from the edge of the substrate to the edge of the display area in a straight line along the injection direction, that is, the length direction of the protrusion 106, with a constant interval. By doing in this way, the drawing-in amount of the sealing material 107 can be easily confirmed visually by the position of the opening shielded by the sealing material 107. That is, by forming the openings intermittently, the window portion 108 can be used as a scale for confirming the amount of the sealing material 107 drawn.

  For example, when only the first opening is shielded by the sealing material 107, the amount of the sealing material 107 drawn is insufficient, and it can be determined that the liquid crystal 109 leaks. Further, when the sealing material 107 is shielded from light up to the fourth opening, the amount of the sealing material 107 drawn is too large to reach the display region, and it can be determined that the display panel is defective.

  Moreover, it is good also as a structure which provides two or more window parts. For example, as shown in FIG. 6, a first window 111 may be provided at approximately the center in the width direction of the inlet 104, and two second windows 112 may be provided so as to contact the sealing material 103. That is, the second window 112 is provided closer to the sealing material near the injection port than the first window 111.

  At this time, the first window 111 has a length substantially the same as the length of the protrusion 106. That is, the first window 111 is formed from the end of the element substrate 101 to the end of the vertical alignment film 105 corresponding to the display region. Further, the second window 112 formed along the sealing material 103 is shorter than the first window 111. In other words, the first window 111 is provided closer to the display area than the second window 112.

  As described above, the sealing material 107 has the largest pulling amount in the center portion in the width direction of the injection port 104 and is not pulled much in the vicinity of the sealing material 103. Therefore, there is a high possibility that the entrapment amount of the sealing material 107 is maximized in the region where the first window 111 is formed. For this reason, the sealing member 107 is excessively drawn by the first window portion 111 and reaches the display area, so that it is possible to determine a panel that has a display defect.

  Further, in the region where the second window portion 112 is formed, there is a high possibility that the amount of the sealing material 107 drawn in is the smallest. For this reason, the length of the 2nd window part 112 is made into the length which wants to draw in the sealing material 107 at the minimum, and the panel with which the drawing-in amount of the sealing material 107 is insufficient can be determined. Note that when the amount of the sealing material 107 is appropriate, the second window portion 112 is shielded from light by the sealing material 107, so that an increase in light leakage can be suppressed.

  In the present embodiment, a vertical alignment liquid crystal display panel has been described, but the present invention is not limited to this. For example, the present invention can be applied to other types of liquid crystal display panels such as a TN mode.

It is a top view which shows the structure of the liquid crystal display panel concerning this invention. It is sectional drawing which shows the structure of the liquid crystal display panel concerning this invention. It is sectional drawing which shows the structure of the window part of the liquid crystal display panel concerning this invention. It is a figure which shows an example of the shape of the window part of the liquid crystal display panel concerning this invention. It is a figure which shows the other example of the shape of the window part of the liquid crystal display panel concerning this invention. It is a figure which shows the other example of the shape of the window part of the liquid crystal display panel concerning this invention. It is sectional drawing which shows the structure of the conventional liquid crystal display panel. It is sectional drawing which shows the structure of the conventional liquid crystal display panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Liquid crystal display panel 101 Element board | substrate 102 Opposite board | substrate 103 Sealing material 104 Inlet 105 Vertical alignment film 106 Projection part 107 Sealing material 108 Window part 109 Liquid crystal 110 Polarizing plate

Claims (7)

A method of manufacturing a liquid crystal display panel in which a liquid crystal is sandwiched between a pair of opposed substrates
A pair of polarizing plates in a crossed Nicol state disposed outside the pair of substrates;
A vertical alignment film provided on opposing surfaces of the pair of substrates;
A sealing material that has an inlet and is provided in a frame shape so as to surround the display region, and which fixes the pair of substrates;
A sealing material for sealing the inlet,
The vertical alignment film has a protrusion provided corresponding to the injection port,
The protrusion is provided with a first window from the tip of the protrusion toward the base .
The first window is provided with a plurality of openings arranged intermittently,
A method for manufacturing a liquid crystal display panel , wherein the quality of the panel is determined based on whether or not the sealing material has reached a specific opening among the plurality of openings . The method of manufacturing a liquid crystal display panel according to claim 1, wherein the plurality of openings are arranged on a straight line along a length direction of the protrusion . The method for manufacturing a liquid crystal display panel according to claim 1, wherein the first window portion is provided at a substantially center of the injection port.   The plurality of openings are arranged so as to reach the end of the display area from the end of the substrate, and when the sealing material reaches only the opening arranged first from the end of the substrate, The method for manufacturing a liquid crystal display panel according to claim 2, wherein the liquid crystal display panel is determined to be defective. A liquid crystal display panel in which liquid crystal is sandwiched between a pair of substrates disposed opposite to each other,
  A pair of polarizing plates in a crossed Nicol state disposed outside the pair of substrates;
  A vertical alignment film provided on opposing surfaces of the pair of substrates;
  A sealing material that has an inlet and is provided in a frame shape so as to surround the display region, and which fixes the pair of substrates;
  A sealing material for sealing the inlet,
  The vertical alignment film has a protrusion provided corresponding to the injection port,
  The protrusion is provided with a first window portion that extends from the distal end to the proximal end of the protrusion, and a second window portion that is shorter than the first window portion that is disposed in contact with the sealing material. And
  A liquid crystal display panel in which the first window is provided closer to the display area than the second window. The liquid crystal display panel according to claim 5 , wherein the quality of the panel is determined based on the amount of the sealing material drawn into the second window portion .   A method of manufacturing a liquid crystal display panel in which a liquid crystal is sandwiched between a pair of opposed substrates,
  A pair of polarizing plates in a crossed Nicol state disposed outside the pair of substrates;
  A vertical alignment film provided on opposing surfaces of the pair of substrates;
  A sealing material which has an injection line and is provided in a frame shape so as to surround the display region, and which fixes the pair of substrates;
  A sealing material for sealing the inlet,
  The vertical alignment film has a protrusion provided corresponding to the injection port,
  The protrusion is provided with a first window portion that extends from the distal end to the proximal end of the protrusion, and a second window portion that is shorter than the first window portion that is disposed in contact with the sealing material. And
  The first window is provided closer to the display area than the second window;
  A method for manufacturing a liquid crystal display panel, wherein the quality of the panel is determined based on the amount of the sealing material drawn into the second window.

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