JP2007156346A - Liquid crystal panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal panel that can display an high definition images and reduce the electrostatic discharge damages (electrostatic flaws). <P>SOLUTION: The liquid crystal panel 10 comprises polarizers 11 and 12, a common glass 13 and a segment glass 14 interposed in between the polarizers 11 and 12, a spacer 15 for holding the common glass 13 and segment glass 14 at a specified interval, and a liquid crystal layer 16 interposed in between the common glass 13 and segment glass 14. The segment glass 14 has an upper electrode 14 disposed in an upper region 14a, a lower electrode 42 disposed in the lower region 14b, and a dummy electrode 43 disposed in the left-side region 14c and the right-side region 14d to connect an upper terminal region 14f in the upper region 14a to a lower terminal region 14g in the lower region 14b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal display panel, and more particularly to a DSTN liquid crystal display panel.

  Conventionally, a liquid crystal display panel (LCD) is used as a flat panel display (FPD). Currently, with the increasing needs for flat panel displays, there is a demand for higher definition of images in liquid crystal display panels used in flat panel displays. In order to increase the definition of an image in the liquid crystal display, it is necessary to increase the number of ITO wirings in the liquid crystal display panel and shorten the distance between the ITO wirings (to a fine pitch).

  There is a DSTN (Dual-scan Super Twisted Nematic) type (DSTN liquid crystal display) as a liquid crystal display panel with high-definition images, but this DSTN liquid crystal display is an improved version of the simple matrix type STN liquid crystal display. Is an improvement. Here, the simple matrix method means that pixels are arranged by sending electrodes on two glass plates with liquid crystal interposed between them in vertical and horizontal grids, and sending electrical signals at the same time in the vertical and horizontal directions. This is a method of lighting (see, for example, Patent Document 1).

The DSTN liquid crystal display is included in the simple matrix type STN liquid crystal display, but in order to improve the response speed, the liquid crystal panel electrode in the segment glass is divided into two vertically and the liquid crystal panel electrodes divided into two vertically are simultaneously formed. I have control. In such a DSTN liquid crystal display, the liquid crystal panel electrodes divided into upper and lower parts use separate drive circuits, so that the display time per dot can be made longer at the same horizontal scanning frequency than the normal STN liquid crystal display. Therefore, the contrast and response speed of the image can be improved. In addition, since the DSTN liquid crystal display can be manufactured at a lower cost than the active matrix TFT liquid crystal display, the DSTN liquid crystal display is used for a low-priced notebook personal computer, a mobile phone display, or the like.
JP 2001-011450 A

  However, the liquid crystal panel electrode (upper electrode 61 and lower electrode 62) divided vertically into the segment glass 64 of the DSTN liquid crystal display has a distance D (center of 10 μm at both terminals 61a and 62a at the central portion of the active area 64e. It arrange | positions so that it may oppose through a gap) (FIG. 6). Since the distance D (center gap) between these terminals 61a and 62a is usually as short as 10 μm, electrostatic breakdown (electrostatic flaw) occurs in the central portion of the active area 64e.

  Here, when static electricity (charge) is applied to the electrode, the electric field E is expressed by the following formula (1) from the formula of the line charge.

E = ρ / 2πε ₀ r (1)
However, (rho) shows the electric charge currently charged to the electrode of 1 m in length, (epsilon) ₀ shows the dielectric constant in the vacuum of an electrode, and r shows distance.

From the above formula (1), it can be seen that the electric field E increases as the distance r decreases. For example, the electrode 72 as shown in FIG. 7, an electrode 71 which spacing is arranged such that D ₁ of the and the electrode 72, arrangement and the interval between the electrode 72 becomes shorter D ₂ than D ₁ In the configuration including the provided electrode 73, when static electricity is applied to the electrode 72 and the electrode 72 is charged and a potential difference is generated between the adjacent electrodes 71 and 73, the electrode 72 and the electrode having a short inter-electrode distance. A discharge 70 occurs between 73.

  That is, it can be seen that the shorter the center gap D, the more likely it is to discharge and cause electrostatic breakdown (electrostatic flaws).

  An object of the present invention is to provide a liquid crystal display panel capable of realizing high definition of an image and reducing the occurrence of electrostatic breakdown (electrostatic flaw).

  In order to achieve the above object, a liquid crystal display panel according to claim 1 comprises two glass substrates comprising a common glass substrate and a segment glass substrate, and a liquid crystal layer interposed between the two glass substrates. In the liquid crystal display panel provided, the segment glass substrate includes an upper electrode disposed in an upper region, a lower electrode disposed in a lower region so as to face the upper electrode with a predetermined interval, and the upper region And a terminal electrode that connects the lower region.

  The liquid crystal display panel according to claim 2 is the liquid crystal display panel according to claim 1, wherein the predetermined interval is 1.0 to 60 μm.

  A liquid crystal display panel according to a third aspect is the liquid crystal display panel according to the first or second aspect, wherein the terminal electrode is disposed in a side region of the segment glass substrate.

  According to the liquid crystal display panel of claim 1, since the terminal electrode connects the upper region and the lower region, it is possible to realize high definition of the image and reduce the occurrence of electrostatic breakdown (electrostatic scratch). be able to.

  According to the liquid crystal display panel of the third aspect, since the terminal electrode is disposed in the side region of the segment glass substrate, high definition of the image can be reliably realized.

  Hereinafter, a liquid crystal display panel according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing a configuration of a liquid crystal display panel according to an embodiment of the present invention.

  In FIG. 1, the liquid crystal display panel 10 holds polarizing plates 11 and 12, a common glass 13 and a segment glass 14 interposed between the polarizing plates 11 and 12, and a gap between the common glass 13 and the segment glass 14 at a predetermined interval. And a liquid crystal layer 16 interposed between the common glass 13 and the segment glass 14.

  An electrode (20 in FIG. 2) made of a transparent conductive film such as an ITO film is formed in the lateral direction (direction A) on the side of the common glass 13 in contact with the liquid crystal layer 16 (lower surface). An alignment film 17 is formed on 20. In addition, the common glass 13 is obtained from mother glass by multi-cavity of 4 vertical x 5 horizontal.

  On the contact surface (upper surface) side of the segment glass 14 with the liquid crystal layer 16, an electrode (FIG. 3) made of a transparent conductive film such as an ITO film in a direction substantially perpendicular to the lateral direction (direction A) (direction B in FIG. 3), and the alignment film 18 is formed on the formed electrode 30. In addition, the segment glass 14 is obtained from mother glass by multi-chamfering of 4 vertical x 5 horizontal.

  FIG. 4 is a diagram illustrating a wiring pattern of the electrodes 30 formed on the segment glass 14 in FIG.

  In FIG. 4, the segment glass 14 includes an upper electrode 41 disposed in the upper region 14a so that the interval C is 20 μm, and a lower electrode 42 disposed in the lower region 14b so that the interval C is 20 μm. The dummy terminal electrode 43 is disposed in the left region 14c and the right region 14d and connects the upper terminal area 14f in the upper region 14a and the lower terminal area 14g in the lower region 14b. Here, the upper electrode 41 and the lower electrode 42 are disposed such that both terminals 41a and 42a face each other with a distance D (center gap) of 10 μm at the center portion of the active area 14e.

  5A and 5B are diagrams for explaining the flow of static electricity. FIG. 5A shows a case where static electricity is applied to the upper electrode 61 of the segment glass 64 in the conventional liquid crystal display panel, and FIG. The case where static electricity is applied to the upper electrode 41 of the segment glass 14 is shown.

  When static electricity is applied to a predetermined position 50 of the upper electrode 61 of the conventional segment glass 64, as shown in FIG. 5A, the electrostatic charge is first transmitted to the entire upper electrode 61 to which static electricity is applied ( Arrow D). Thereafter, the charge transmitted to the entire upper electrode 61 to which static electricity has been applied moves (discharges) from the upper electrode 61 to which static electricity has been applied to another upper electrode 61 in the upper terminal area 64f (arrow E). Thereafter, the charges that have moved to the other upper electrode 61 move from the upper terminal area 64f toward the central portion of the active area 64e (arrow F). In the conventional segment glass 64, since the upper region 64a and the lower region 64b are not connected, the applied electrostatic charge can move only within the upper region 64a of the segment glass 64. Therefore, a potential difference is generated between the upper electrode 61 and the lower electrode 62. When the generated potential difference exceeds the static electricity resistance of the segment glass 64, a discharge occurs between the terminals 61a and 62a, and electrostatic breakdown (static Electric flaws) occur.

  On the other hand, when static electricity is applied to the predetermined position 50 of the upper electrode 41 of the segment glass 14 according to the present invention, as shown in FIG. (Arrow D). Thereafter, the charge transmitted to the entire upper electrode 41 to which static electricity is applied moves (discharges) from the upper electrode 41 to which static electricity is applied to another upper electrode 41 in the upper terminal area 14f (arrow E). Thereafter, the charges that have moved to the other upper electrode 41 to which static electricity has been applied move from the upper terminal area 14f toward the central portion of the active area 14e (arrow F), and in addition, the dummy terminal electrode 43 is moved to the upper terminal area. It moves from the area 14f through the active area 14e toward the lower terminal area 14g (arrow G). The charges that have moved through the dummy terminal electrode 43 move (discharge) from the dummy terminal electrode 43 to the lower electrode 42 in the lower terminal area 14g (arrow H). Thereafter, the electric charge moved to the lower electrode 42 moves from the lower terminal area 14g toward the central portion of the active area 14e (arrow I).

  As described above, the segment glass 14 of the liquid crystal display panel 10 has a configuration in which the dummy terminal electrode 43 connects the upper terminal area 14f in the upper region 14a and the lower terminal area 14g in the lower region 14b. Even when static electricity is applied to a predetermined position 50 of 41, the electrostatic charge is moved not only to the upper electrode 41 but also to the lower electrode 42 to reduce the potential difference between the upper electrode 41 and the lower electrode 42. Therefore, the occurrence of electrostatic breakdown (electrostatic flaw) due to the discharge between the terminals 41a and 42a can be reduced.

  Next, specific examples according to the present invention will be described.

  A transparent conductive film formed on the entire surface is patterned, an alignment film is applied, rubbing is performed, a seal and paste are printed on each glass surface, and a 0.7 mm thick common glass and segment glass are prepared. The prepared common glass and segment glass were combined through a spacer, liquid crystal was injected into the gap between the two glasses, and pressure was applied while heating to a predetermined liquid crystal layer thickness to cure the seal.

  As a result, the number of pixels is 96 × vertical × 237, the size of the pixel is 0.22 mm × 0.325 mm, the pixel pitch is 0.24 mm × 0.345 mm, the width of the wiring area is 1 mm, the panel A simple matrix driving liquid crystal display panel having a vertical size of 52.56 mm × 67.7 mm and a transparent conductive film (electrode) resistance value of 30Ω / □ was produced.

  In addition, as the segment glass, a glass having a dummy terminal electrode (Example) and a glass having no dummy terminal electrode (Comparative Example) were used.

  Table 1 shows the results of static driving by applying a voltage of 1.68 V and 64 Hz to the manufactured liquid crystal display panel and viewing it in the entire display state. The display mode was a monochrome mode with a transflective retardation film.

  From Table 1, when the dummy terminal electrode is provided on the segment glass (Example), the occurrence rate of electrostatic flaws (black circles) can be significantly reduced as compared with the case where the dummy terminal electrode is not provided on the segment glass (Comparative Example). I understand.

  Further, even when a voltage of 5.00 V was applied to the liquid crystal display panel provided with the dummy terminal electrodes, no electrostatic flaw was generated. From this, it can be seen that when the dummy terminal electrode is provided on the segment glass, the resistance to static electricity can be improved three times or more.

  According to the present embodiment, the dummy terminal electrodes 43 are disposed in the left side region 14c and the right side region 14d of the segment glass 14, and the upper terminal area 14f in the upper region 14a and the lower terminal area 14g in the lower region 14b are connected. Since they are connected, it is possible to realize high definition of the image of the liquid crystal display panel 10 and to reduce the occurrence of electrostatic breakdown (electrostatic scratches) due to the discharge between the terminals 41a and 42a.

  In the present embodiment, multiple chamfering is performed by extracting a plurality of glasses from a single mother glass. However, the present invention is not limited to this, and even when single chamfering is performed by extracting one glass from a single mother glass. Good.

It is sectional drawing which shows roughly the structure of the liquid crystal display panel which concerns on embodiment of this invention. It is a figure explaining the common glass 13 in FIG. It is a figure explaining the segment glass 14 in FIG. It is a figure explaining the wiring pattern of the electrode 30 formed in the segment glass 14 in FIG. It is a figure explaining the flow of an electrostatic charge, (a) shows the case where static electricity is applied to the upper electrode 61 of the segment glass 64 in the conventional liquid crystal display panel, (b) shows the segment glass 14 in FIG. A case where static electricity is applied to the upper electrode 41 is shown. It is a figure explaining the wiring pattern of the electrode formed in the segment glass 64 in the conventional liquid crystal display panel. It is a figure explaining the electric discharge which generate | occur | produces between the electrodes in the conventional liquid crystal display panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid crystal display panel 11 Polarizing plate 12 Polarizing plate 13 Common glass 14 Segment glass 14a Upper area | region 14b Lower area | region 14c Left side area | region 14d Right side area | region 14f Upper terminal area 14g Lower terminal area 41 Upper electrode 42 Lower electrode 43 Dummy terminal electrode

Claims (3)

  In a liquid crystal display panel comprising two glass substrates comprising a common glass substrate and a segment glass substrate, and a liquid crystal layer interposed between the two glass substrates, the segment glass substrate is disposed in an upper region. An upper electrode, a lower electrode disposed in a lower region so as to face the upper electrode with a predetermined interval, and a terminal electrode connecting the upper region and the lower region. LCD display panel.   The liquid crystal display panel according to claim 1, wherein the predetermined interval is 1.0 to 60 μm.   The liquid crystal display panel according to claim 1, wherein the terminal electrode is disposed in a side region of the segment glass substrate.

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