JP2006058651A - Liquid crystal display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which satisfactorily performs liquid display in different display modes on one display screen, has high durability against external stress such as impact, can keep a wide effective display area within the display screen, and has flexibility in arrangement design in display regions for different display modes. <P>SOLUTION: The liquid crystal display panel 1 has a plurality of display regions for displaying information in different display modes on one display screen, wherein the plurality of display regions are segmented by a sealing material 4 (4a) arranged between a pair of panel substrates 2, 3 having at least a transparent electrode and an alignment layer, and further, and the plurality of display regions are formed by making different gap dimensions in the plane between the pair of panel substrates 2, 3 constituting the respective display regions. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display panel having a plurality of display areas in the same plane on which information is displayed in different liquid crystal display modes.

  In general, as a liquid crystal display panel, a TN (Twisted Nematic) type liquid crystal display panel, an MTN (Multi-Domain Twisted Nematic) type liquid crystal display panel that locally changes the retardation value of the liquid crystal layer and eliminates the entire coloring caused by the retardation, There are known HTN (High Quality Twisted Nematic) type liquid crystal display panels and STN (Super Twisted Nematic) type liquid crystal display panels that use a liquid crystal having a high retardation value to make the background blacker and improve the appearance.

  Each of these liquid crystal display panels is configured to enclose liquid crystal between a pair of panel substrates arranged to face each other, but the gap dimension between the pair of liquid crystal display panels is the same as that of the liquid crystal display panel. It varies depending on the display method (display mode) using the characteristics of the liquid crystal appropriately selected according to the purpose of use.

  For example, as a display body that employs a method in which electrodes are arranged in a grid pattern and desired information is displayed in a full dot display (hereinafter simply referred to as “full dot display”), a retardation plate is recently added to an STN liquid crystal display panel. A liquid crystal display panel to which an optical compensation function member such as the above is added is widely used (a display mode using this liquid crystal display panel is referred to as “FSTN mode”). In the FSTN mode, an optimum display can be performed when the gap size of the STN type liquid crystal display panel is set to a relatively narrow value of 5 to 7 μm. However, the tolerance of the gap dimension is strict, and it is desirable that the specification be suppressed to ± 0.1 μm from the viewpoint of preventing color unevenness.

  In addition, as a display body that employs a method of displaying a bar graph or a character such as a water pressure gauge or a fuel gauge in a segment display (hereinafter also referred to as a “segment display”), the TN liquid crystal display panel and the HTN liquid crystal display are used. Display panels, MTN liquid crystal display panels, and the like are widely used (display modes using these liquid crystal display panels are sequentially referred to as “TN mode”, “HTN mode”, and “MTN mode”). In each of these display modes, the gap size of each liquid crystal display panel is set to 6 to 12 μm, which is wider than that of the STN type liquid crystal display panel to ensure light shielding and prevent light leakage in the background. Yes. Since the gap dimension can be set relatively wide in this way, the tolerance is relatively gradual, and a uniform background color can be obtained even by setting it to ± 0.3 μm.

  By the way, a liquid crystal display panel having a display area for full dot display and a display area for segment display in the same display surface, such as an instrument panel or a navigation system of an automobile, in other words, For example, a liquid crystal display panel having a display for full dot display mode and a display for segment display is often used in the same device.

  In a liquid crystal display panel having such two different display bodies, in order to obtain an optimal display for both full dot display and segment display, the gap dimension between the panel substrates is made different for each display body. There is a need.

  Therefore, conventionally, a pair of independent panel substrates is prepared for each display body, and the two sets of panel substrates are coupled in either the vertical or horizontal direction, and the display panel of the liquid crystal display device has its The display areas are arranged in parallel.

  However, in the liquid crystal display panel having such a configuration, the joint portion between both panel substrates is easily cracked or damaged by an external stress such as contact. And in order to prevent this, if it is set as the structure which arrange | positions so that the display area may be arranged in parallel within the display surface of a liquid crystal display panel, providing a gap | interval between two sets of panel substrates, the external shape of a liquid crystal display panel The effective display area for the dimensions is reduced. In addition, since the display interval of each display mode is widened, the sense of unity between the displays is reduced. Furthermore, if the minimum gap size is to be set, it is preferable to form the connecting portion in a straight line, but with such a configuration, the arrangement design of the display area for full dot display and the display area for segment display The degree of freedom is limited.

  Another method is to adopt the same display mode at the expense of the display characteristics of either one of the display mode for full dot display and the display mode for segment display. Both the display content of the display and the display content (character) of the segment display have been displayed.

  Specifically, an STN liquid crystal display panel having a gap size set to 5 to 7 μm is adopted as the display body, and 1/32 in a part of the display area of the STN liquid crystal display panel in the STN mode. Full dot display is performed with time-division driving of about 1/100 Duty, and characters are displayed with static driving or time-division driving of about 1/2 to 1/4 Duty in other areas.

  When performing display as shown in this conventional example, as described above, the STN type liquid crystal display panel is originally suitable for full dot display, so that optimum visibility is obtained in the display area of full dot display. Can do. However, in the display area for displaying the segment display, the display quality has many problems. That is, the liquid crystal used in the STN type liquid crystal display panel has a higher twisting voltage than the liquid crystal used in the TN type liquid crystal display panel or the HTN type liquid crystal display panel suitable for segment display, and therefore, the drive voltage becomes high. In addition, when an appropriate high voltage is set to improve the display quality of the display area where segment display is performed, the drive voltage in the display area of full dot display is expected to exceed the operating breakdown voltage of the LSI. . In order to reduce the driving voltage due to the limitation on the driving withstand voltage of LSI, it is conceivable to use a low-voltage liquid crystal. However, if the low duty is driven with this specification, the driving voltage will be too low. There were problems in terms of contrast and responsiveness. Furthermore, the STN type liquid crystal has a greater light-blocking temperature dependency than the TN, MTN, and HTN type liquid crystal, and depending on the ambient temperature when performing liquid crystal display with display content suitable for segment display. There was also a problem that the background color was not displayed well.

  Accordingly, the present invention can satisfactorily perform liquid crystal display in which display modes are different within the same display surface, and is resistant to external stress such as impact, and ensures a wide effective display area within the display surface. In addition, an object of the present invention is to provide a liquid crystal display panel having a high degree of freedom in layout design of display areas in different display modes.

  In order to achieve the above-described object, the present invention is characterized in that, in a panel having a plurality of display areas in which information is displayed in different display modes within the same display surface, the plurality of display areas include a transparent electrode and an alignment film. The plurality of display areas are formed with different in-plane gap dimensions between the pair of panel substrates constituting each display area. It is in the point. And the liquid crystal which shows each different characteristic is enclosed in the surface of a pair of panel board | substrate which comprises each display area of the said several display area, It is characterized by the above-mentioned. Further, at least one display area of the plurality of display areas is characterized in that an opposing surface of at least one of the pair of panel substrates is excavated.

  According to the liquid crystal display panel of the present invention, each display region can be partitioned and formed with a gap size optimum for the display mode of the information and the characteristics of the liquid crystal to be sealed between a pair of panel substrates arranged opposite to each other. In addition, it is possible to satisfactorily perform liquid crystal display in which display modes are different within the same display surface.

  In addition, since the plurality of display areas are defined by a sealing material disposed between the pair of panel substrates, a coupling portion is not formed between the display areas as in the prior art. The structure is robust against external stress.

  Furthermore, since only the sealing material is arranged between the display areas of different display modes, a large effective display area in the display surface can be secured, and furthermore, the sealing material that partitions each display area Regardless of whether they are linear or curved, they can be arranged freely and simply, and the degree of freedom in designing the arrangement of display areas in different display modes can be increased.

  The in-plane gap dimension adjustment between the pair of panel substrates is performed by adjusting the pair of panel substrates together with the gap dimension of the display area having the narrowest gap dimension as an appropriate dimension among the plurality of display areas. With respect to the other display areas, an appropriate gap dimension can be secured by excavating the facing surface of at least one of the pair of panel substrates.

  FIG. 1 is a conceptual cross-sectional view showing characteristic components of the liquid crystal display panel of the present embodiment, and FIG. 2 is a conceptual plan view thereof.

  The liquid crystal display panel 1 of the present embodiment is a liquid crystal display panel 1 having two display areas in which information is displayed in different display modes within the same display surface, and the two display areas are arranged to face each other. A pair of panel substrates 2 and 3 are partitioned by a sealant 4, and each display region takes into account the characteristics of the liquid crystal sealed in the plane between the panel substrates 2 and 3 in each display region. The desired gap dimensions are formed with different widths.

  In the present invention, the gap dimension means an average value of the in-plane gap dimension between the panel substrates 2 and 3 in each display region. As will be described later, there is a display method (MTN mode) that dare to use the fine uneven shape of the opposing surfaces of the pair of panel substrates 2 and 3 depending on the case, and there is a tolerance range for the gap dimension in the surface. For this reason, the gap dimension does not necessarily have to be the same at any location in the plane.

  More specifically, the liquid crystal display panel 1 of the present embodiment has a pair of panel substrates 2 and 3 made of glass substrates that are arranged to face each other substantially parallel across the narrowest gap dimension among the plurality of display regions. is doing. One panel substrate 3 of the pair of panel substrates 2 and 3 has an area corresponding to a display region (hereinafter, referred to as a wide gap region) in which the gap dimension is widely formed on the opposing surface. A concave portion is formed by excavating from a region corresponding to a display region (hereinafter referred to as a narrow gap region) formed with a small size. The wide gap region of the panel substrate 3 can be processed into a concave shape by etching the surface of the glass substrate as the panel substrate 3 using hydrofluoric acid, for example. In the present embodiment shown in FIG. 1, a case is shown in which only one of the opposing surfaces of the panel substrate 3 in the wide gap region (the panel substrate positioned below in the figure) is processed into a concave shape. However, the opposing surfaces of the pair of panel substrates 2 and 3 constituting the wide gap region may be processed into a concave shape.

  A transparent electrode (not shown) made of indium tin oxide (hereinafter referred to as ITO) or the like is laminated on the opposing surfaces of the panel substrates 2 and 3. An alignment film (not shown) is provided on the surface of the panel substrates 2 and 3 on which the transparent electrodes are formed, in order to arrange the liquid crystal in a certain form between the electrodes facing each other. Are stacked. The pair of panel substrates 2 and 3 are bonded and integrated on the outer periphery between the opposing surfaces of the pair of panel substrates 2 and 3 and the boundary between the two display regions in the narrow gap region. The sealing material 4 is disposed. The arrangement position of the sealing material 4 (4a) that partitions the two display regions is not limited to the boundary portion in the narrow gap region, but may be the boundary portion in the wide gap region. However, in the manufacturing process of the liquid crystal display panel 1, the sealing material is formed on the surface of the panel substrate 2 (3) before bonding the substrates, and is disposed on the outer periphery between the opposing surfaces of the pair of panel substrates 2 and 3. It is preferable that the sealing material 4 (4a) for partitioning the two display areas is disposed in the narrow gap region because it can be made the same as the height of the sealing material 4 and is simple.

  In the plane, liquid crystal (not shown) having an optimum specification of the gap size of each display region is sealed. As a result, two types of liquid crystal layers are formed in the plane of the pair of panel substrates 2 and 3.

  In addition, in FIG. 1, the arrangement | positioning relationship between a pair of panel board | substrates 2 and 3 and the sealing material 4 is shown, and illustration of the said other component is abbreviate | omitted.

  The liquid crystal display panel 1 configured in this way is divided between a pair of opposed panel substrates 2 and 3 with a gap size optimal for the display mode of information and the characteristics of the liquid crystal to be sealed. The liquid crystal display can be satisfactorily performed by changing the display mode within the same display surface.

  In this embodiment, the liquid crystal display panel 1 is configured to perform full dot display in the narrow gap region on the same display surface and perform segment display in the other wide gap region.

  Specifically, STN liquid crystal suitable for full dot display is sealed in the plane in the narrow gap region, and liquid crystal suitable for segment display, for example, TN liquid crystal, is sealed in the plane in the wide gap region. It is realized with. In the specification of the present embodiment, these gap dimensions can be freely set within the optimum gap dimension of the liquid crystal used in each display mode described above.

  In general, examples of a display mode in which it is desirable to use a narrow gap region include an STN mode (preferable gap size: 4 to 7 μm) and a field sequential mode (preferable gap size of 2 to 3 μm). Therefore, the gap dimension in the plane of the narrow gap region may be freely designed in the range of 2 to 7 μm according to the type of liquid crystal to be sealed. In that case, it is desirable to suppress the tolerance to a maximum value of 0.1 μm or less.

  On the other hand, display modes that desirably use a wide gap region include TN mode (preferable gap size: 8 to 12 μm), MTN mode (preferable gap size: 8 to 10 μm), and HTN mode (11 to 12 μm). Can be illustrated.

  Therefore, the in-plane gap size of the wide gap region may be freely designed in the range of 8 to 12 μm according to the type of liquid crystal to be sealed. In this case, it is desirable to suppress the tolerance to a maximum value of 0.7 μm or less.

  In each display area, by performing display in the STN mode and the TN mode, the characteristics of each sealed liquid crystal can be fully utilized. In other words, optimum visibility can be obtained in a narrow gap region in which full dot display is performed in the STN mode, and excellent light shielding properties and contrast and responsiveness are excellent in a wide gap region in which segment display is performed in the TN mode. Display can be made. Further, since the plurality of display areas are partitioned by the sealing material 4 disposed between the pair of panel substrates 2 and 3, no coupling portion is formed between the display areas as in the prior art. Therefore, it is possible to prevent the joint from being cracked by an external stress such as an impact, resulting in a robust structure. Furthermore, since only the sealing material 4 (4a) is arranged between the display areas of different display modes, a wide effective display area in the display surface can be secured. Furthermore, as shown in FIG. 2, the sealing material 4 (4a) for partitioning each display area is not limited to a straight line and can be arranged freely and easily. The degree of freedom can also be increased.

  The following is a liquid crystal display having a plurality of display areas in which information is displayed in different display modes on the same display surface as described above, and having different gap dimensions in the plane of each display area. A specific example of the panel will be described.

Example 1:
The liquid crystal display panel of this embodiment has a display area for performing full dot display in the FSTN mode and a display area for performing segment display in the MTN mode within the same display surface.

  The display area for performing full dot display in the FSTN mode is configured such that STN liquid crystal is sealed in a narrow gap area, and a temperature compensation phase difference plate is provided.

  The display area for performing segment display in the MTN mode is formed into a wide gap area by digging the opposing surface of the panel substrate into a concave shape by a chemical etching process using hydrofluoric acid, and the surface of the concave opposing surface is not conscious. In particular, irregularities having an average roughness (Rz) of 3 to 7 μm are formed and TN type liquid crystal is sealed in the surface.

  In the liquid crystal display panel configured as described above, optimum visibility can be obtained in the narrow gap region as described above, and various gap values can be obtained even in the wide gap region due to the unevenness formed on the substrate surface. In other words, by having various retardation values (Δn · d), it is possible to display a wide range of coloration due to retardation, and to display white and black, which are mixed colors of various colors, with excellent visibility. A good display can be performed.

Example 2:
The liquid crystal display panel of this embodiment has a display area for performing full dot display in the FSTN mode and a display area for performing segment display in the TN mode using a TN type liquid crystal to which a dye is added within the same display surface. .

  The display area for performing full dot display in the FSTN mode is configured such that STN liquid crystal is sealed in a narrow gap area, and a temperature compensation phase difference plate is provided.

  In addition, the display area for performing segment display in the TN mode is configured by enclosing TN type liquid crystal added with a dye in a wide gap area by digging the opposing surface of the panel substrate into a concave shape by an etching process. ing.

  Even if the TN type liquid crystal to which a dye is added has a poor smoothness of the concave facing surface etched in the wide gap region, and the tolerance of the gap size of the wide gap region reaches 0.7 μm. , It has the advantage that a uniform background color can be obtained due to its characteristics. When the tolerance is about 0.3 μm, the purpose of making the background color uniform can also be achieved by enclosing a normal TN type liquid crystal in the plane of the wide gap region.

  In any of the liquid crystal display panels configured as described above, optimum visibility can be obtained in the narrow gap region as described above, and the light shielding property is excellent in the wide gap region, and the contrast and responsiveness are good. Such as being able to perform various displays.

Example 3:
The liquid crystal display panel of this embodiment has a display area for performing segment display by static drive by a field sequential method for performing high-speed switching of a light source and a display for displaying character dots by 1/8 duty time-division drive on the same display surface. And having a region.

  In the liquid crystal display panel of this embodiment, the display area for performing the segment display by the field sequential method is TN type liquid crystal having a response speed of 5 msec in a narrow gap area. The display area for displaying character dots by time-division driving is configured by enclosing a TN type liquid crystal with a response speed of 150 msec in a wide gap area by digging the opposing surface of the panel substrate into a concave shape by etching. Yes.

  In a liquid crystal display panel configured in this manner, in a narrow gap region, by using a TN type liquid crystal having a high response speed in a field sequential method, the high speed switching of the light source follows the twist characteristics of the TN type liquid crystal. Optimum visibility can be obtained in color display. In addition, when a liquid crystal having a normal response speed is used in the narrow gap region, it becomes easier to control the driving voltage in the wide gap region than in the case of using a liquid crystal for high speed response in the narrow gap region. It is possible to obtain an effect that a display with good responsiveness can be performed.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed.

  For example, the means for adjusting the gap size in each display region is an etching method using the hydrofluoric acid even when the gap size is widened by excavating the opposing surface of the panel substrate as described above. Not exclusively. For example, excavation by a sandblast method may be used. Furthermore, the gap dimension can be narrowed by forming a thin film on the opposing surface of the panel substrate.

  Further, in the present embodiment, the case where two different display areas are arranged in the same display surface of the liquid crystal display panel has been described. However, if the liquid crystal can be sealed in the surface between the panel substrates, the same Three or more different display areas may be arranged in the display surface.

  Display body for control, security, and control of vehicles, ships, aircraft, etc. that arranges the full dot display area and segment display area on the same display surface, or a high-speed response area of several msec level and several hundred msec level The above normal response area can be used as a display for entertainment / game equipment and portable communication terminal device terminal equipment in which the normal response area is arranged in the same display surface.

Sectional conceptual diagram which shows the characteristic component part of the liquid crystal display panel of this embodiment FIG. 1 is a conceptual plan view of the liquid crystal display panel of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 2, 3 Panel board | substrate 4 Sealing material 4a (Different display area is divided) Sealing material

Claims (3)

In a liquid crystal display panel having a plurality of display areas in which information is displayed in different display modes within the same display surface,
The plurality of display areas are defined by a sealing material disposed between a pair of panel substrates having at least a transparent electrode and an alignment film,
The liquid crystal display panel, wherein the plurality of display areas are formed with different in-plane gap dimensions between a pair of panel substrates constituting each display area.   The liquid crystal display panel according to claim 1, wherein liquid crystals having different characteristics are sealed in a plane between a pair of panel substrates constituting each display area of the plurality of display areas. 3. The liquid crystal display panel according to claim 1, wherein in at least one display region of the plurality of display regions, a facing surface of at least one of the pair of panel substrates is excavated.