JP4499461B2 - Liquid crystal display panel and large liquid crystal display device - Google Patents

Description

  The present invention relates to a liquid crystal display panel and a large liquid crystal display device, and in particular, a liquid crystal display panel in which a chiral nematic liquid crystal having a liquid crystal alignment in a planar alignment or a focal conic alignment is sandwiched between a pair of substrates, and a large size using the liquid crystal display panel The present invention relates to a liquid crystal display device.

  Conventionally, a liquid crystal display panel has been widely used as a display screen of a personal computer, a portable information terminal or the like because it is thin and light and consumes less power.

  In this liquid crystal display panel, a plurality of transparent electrodes are provided on the inner surfaces of a pair of substrates facing each other, and both the substrates are integrally formed by a sealing material disposed on the peripheral edge of the inner surfaces of both substrates. Yes. As the sealing material, a black or gray sealing material in which a black dye or pigment is mixed in a resin material such as an epoxy thermosetting resin is mainly used. Liquid crystal is sealed inside the substrates and the sealing material, and a portion where the liquid crystal is sealed serves as a display area for displaying on the liquid crystal display panel.

  In recent years, chiral nematic liquid crystal has been used as the liquid crystal of such a liquid crystal display panel.

  This chiral nematic liquid crystal is a liquid crystal obtained by adding a chiral agent (optically active substance) to nematic liquid crystal, and has a spiral structure in which the alignment direction of the liquid crystal rotates at regular intervals.

  When a spiral nematic liquid crystal has a planar arrangement in which the spiral axis of the chiral nematic liquid crystal is substantially perpendicular to both substrates, it reflects light of a specific wavelength corresponding to the direction of twist of the spiral axis. The phenomenon of reflecting light of a specific wavelength in this planar arrangement is called selective reflection. On the other hand, when the spiral axis of chiral nematic liquid crystal is a focal conic arrangement in which the spiral axis is random or non-perpendicular to both substrates, the liquid crystal as a whole exhibits a weak scattering state and reflects light of a specific wavelength. It is designed to transmit light.

  In the chiral nematic liquid crystal display panel using the chiral nematic liquid crystal, a voltage is applied to the chiral nematic liquid crystal through each transparent electrode so that the planar arrangement and the focal conic arrangement of the chiral nematic liquid crystal can be switched. An arbitrary chiral nematic liquid crystal is used as a planar arrangement to cause selective reflection, and light is scattered in a portion of the focal conic arrangement (see, for example, Patent Documents 1 and 2).

  According to such a chiral nematic liquid crystal display panel, display can be performed by switching the planar arrangement and the focal conic arrangement of the chiral nematic liquid crystal. Therefore, a desired display is possible without using a backlight for irradiating the liquid crystal display panel with light or a polarizing plate for transmitting or blocking light in a predetermined polarization direction. The use of chiral nematic liquid crystal display panels has attracted attention in portable information terminals and the like where further reduction in thickness and reduction in power consumption are desired.

  Here, for example, in an STN or TFT type liquid crystal display panel that performs negative display with a dark background and a bright display, the arrangement of the liquid crystal sealing region and the seal material inside the seal is achieved by using a conventional black seal material. The boundary with the region can be obscured.

  However, in the chiral nematic liquid crystal display panel, since the seal material such as black or gray has a color different from the selective reflection color of the liquid crystal encapsulated region, the arrangement region of the liquid crystal encapsulated region and the seal material 11 as shown in FIG. The boundary between and becomes clear. For this reason, when the arrangement area of the sealing material 11 is visible when the chiral nematic liquid crystal display panel 12 is used as a display screen, the boundary line of the display area is clearly recognized, and the display screen is not good and the display screen is narrow. It will be visible. Therefore, when the chiral nematic liquid crystal display panel 12 is mounted on a display device, the arrangement area of the sealing material 11 has to be hidden as a non-display area.

  Furthermore, the selective reflection color obtained in the chiral nematic liquid crystal display panel 12 is a glittery lame tone and has a different texture from the non-glossy color of the sealing material 11. The visual impression will be very different. For this reason, the boundary line of the liquid crystal sealing region is clearer, and when the arrangement region of the sealing material 11 is seen, it looks bad.

Japanese Patent Laid-Open No. 2002-107713 JP 2003-295223 A

  The present invention has been made in view of these points, and is a liquid crystal display panel using a chiral nematic liquid crystal, and can display a display screen wider than an actual liquid crystal encapsulated region and a large liquid crystal display. An object is to provide an apparatus.

  In order to achieve the above object, the liquid crystal display panel according to the first aspect of the present invention is characterized in that an electrode is provided on the inner surfaces of a pair of substrates facing each other, and the sealing material disposed on the inner surfaces of the two substrates In the liquid crystal display panel in which both substrates are integrally formed, and chiral nematic liquid crystal in which the liquid crystal alignment becomes a planar alignment or a focal conic alignment by an applied voltage is enclosed inside the both substrates and the sealing material, The color of the sealing material has a color difference of 6 or less compared to the selective reflection color obtained by selective reflection in the planar arrangement, or the peak wavelength of the spectral spectrum of the color of the sealing material and the peak wavelength of the spectral spectrum of the selective reflection color The difference is 20 nm or less, and is a glossy lame color.

  Here, the color difference is a numerical value representing a difference between two colors, and specifically, refers to a linear distance ΔE * ab between two color coordinates positioned in the CIE1976L * a * b * color space.

  According to the first aspect of the present invention, since the texture of the color of the sealing material and the texture of the selective reflection color can be made the same, the boundary between the liquid crystal sealing area and the arrangement area of the sealing material can be obscured. it can.

  The liquid crystal display panel according to claim 2 is characterized in that the particle size of the coloring material for coloring the sealing material in a glossy lame color is equal to or smaller than the gap size of the two substrates. is there.

  According to the second aspect of the invention, the particles of the coloring material can be evenly arranged between the two substrates, and the sealing material can be made uniform in color as a whole.

  The liquid crystal display panel according to the third aspect of the invention is characterized in that a pearl pigment is used as the colorant.

  According to the third aspect of the present invention, the sealing material can be colored in a glossy lame color with the pearl pigment.

  The liquid crystal display panel according to claim 4 is characterized in that a conductive material is used as the colorant, and a predetermined electrode between the two substrates is conducted by the conductive colorant. There is in point.

  According to the fourth aspect of the present invention, by connecting the predetermined electrode on one substrate and the predetermined electrode on the other substrate through the coloring material, the coloring material can be used without using a dedicated conductive material. Thus, a predetermined electrode between both substrates can be made conductive.

  Furthermore, the large-sized liquid crystal display device according to the invention described in claim 5 is characterized in that a plurality of liquid crystal display panels according to any one of claims 1 to 4 are arranged in parallel on a plane. In the point.

  According to the invention described in claim 5, since the texture of the color of the sealing material and the selective reflection color can be made the same, it is difficult to recognize the boundary between the arrangement area of the sealing material and the liquid crystal sealing area. Adjacent portions of the liquid crystal display panels can also be made inconspicuous.

  As described above, according to each liquid crystal display panel according to the present invention, it is difficult to recognize the boundary line between the liquid crystal sealing region and the sealing material arrangement region, so that the liquid crystal display panel is used as a display screen. In the case of mounting, the appearance of the seal material is not bad even when the seal material arrangement area is visible, and the display screen can be made wider than the actual display area by showing the seal material arrangement area.

  Further, according to the large-sized liquid crystal display device according to the present invention, even if the arrangement region of the sealing material and the adjacent portion of each liquid crystal display panel can be seen, it does not look bad and the display screen can look good.

  Hereinafter, an embodiment of a liquid crystal display panel according to the present invention will be described with reference to FIGS. In this embodiment, a liquid crystal display panel using chiral nematic liquid crystal will be described as a reflective liquid crystal display panel that does not use a polarizing plate, but the present invention is not limited to this.

  FIG. 1 is a schematic cross-sectional view showing a liquid crystal display panel according to the present embodiment.

  As shown in FIG. 1, the liquid crystal display panel 1 has a pair of transparent substrates 2, and a plurality of transparent substrates 2 made of ITO (Indium Tin Oxide) or the like are formed on the mutually opposing inner surfaces. A transparent electrode 4 is provided.

  A sealing material 3 is disposed on the peripheral edge portions of the inner surfaces of the two transparent substrates 2, and the two transparent substrates 2 are bonded together by the sealing material 3. The sealing material 3 is formed of the two transparent substrates 2. 2 are arranged so as to reach the end edges 2a of the transparent substrates 2 as shown in FIG.

  A chiral nematic liquid crystal 5 is sealed as a liquid crystal inside the transparent substrate 2 and the sealing material 3, and the chiral nematic liquid crystal 5 is configured by adding a chiral agent to the nematic liquid crystal. The chiral nematic liquid crystal 5 selectively reflects light of a specific wavelength when it is in a planar arrangement, and scatters light when it is in a focal conic arrangement. A voltage is transmitted through each transparent electrode 4. By being applied, the planar arrangement and the focal conic arrangement can be switched.

  Note that the selective reflection color displayed on the liquid crystal display panel 1 by selective reflection when the chiral nematic liquid crystal 5 is planar is arranged such that the gap size between the transparent substrates 2 and the chiral nematic liquid crystal 5 rotate once on the spiral axis. An arbitrary color can be set by adjusting the liquid crystal pitch, which is the distance between them.

  A portion of the liquid crystal display panel 1 in which the chiral nematic liquid crystal 5 is sealed is a liquid crystal sealing region including a display region for displaying on the liquid crystal display panel 1.

  Further, the color of the sealing material 3 described above has a color difference of 6 or less from the selective reflection color in the liquid crystal sealing region, or the peak wavelength in the spectral spectrum of the color of the sealing material and the spectral reflection of the selective reflection color as shown in FIG. The difference from the peak wavelength in the spectrum is 20 nm or less, and it is formed so as to have a glossy lame color.

  Specifically, for example, a coloring material 6 such as a pearl pigment of an arbitrary color within 3 to 10 wt% with respect to the weight of the sealing material 3 used for each liquid crystal display panel 1 is mixed to selectively reflect the sealing material 3. The color is similar to the color, preferably the same system, and has a glossy lame color.

  As the coloring material 6, for example, a pearl pigment having an insulating property in which mica or quartz is coated with titanium oxide, iron oxide, or the like can be used. Moreover, various things, such as a pigment which consists of metal powder, and the dye which dye | stains the sealing material 3 in a glossy glitter color, can be used.

  Further, a conductive material is used as the coloring material 6, and the predetermined transparent electrode 4 on one transparent substrate 2 and the predetermined transparent electrode 4 on the other transparent substrate 2 are connected via the conductive coloring material 6. By connecting, a predetermined transparent electrode 4 can be conducted between the transparent substrates 2. For example, a conductive colorant using a metallic substance such as aluminum is used.

  As the coloring material 6 and the like mixed in the sealing material 3, it is preferable to use the coloring material 6 and the like having a particle size equal to or smaller than the gap size in consideration of the gap size of the transparent substrates 2.

  Further, by providing a light absorbing layer 8 of an arbitrary color on the back side of the liquid crystal display panel 1, when the chiral nematic liquid crystal 5 has a focal conic arrangement, light is scattered in the focal conic arrangement portion, and light is absorbed in the display area. An indication of the color of the layer 8 can be obtained.

  The present liquid crystal display panel 1 has a light absorption layer 8 obtained by scattering light with a selective reflection color in the planar arrangement portion of the chiral nematic liquid crystal 5 as a background color and an arbitrary chiral nematic liquid crystal 5 as a focal conic arrangement. The display color is used as a display color, and a desired display is performed.

  Next, the operation of this embodiment will be described.

  According to this embodiment, the color of the sealing material 3 is similar to the color of selective reflection in the liquid crystal sealing region, that is, the background color, and preferably the same color and a glossy lame color. Therefore, the boundary between the liquid crystal sealing area and the arrangement area of the sealing material 3 can be obscured.

  Therefore, it is difficult to recognize the boundary line between the liquid crystal sealing area and the arrangement area of the sealing material 3. Therefore, when the liquid crystal display panel 1 is mounted on a display device as a display screen, the arrangement area of the sealing material 3 is Even if it can be seen, it does not look bad, and the display screen can be shown wider than it actually is by showing the arrangement area of the sealing material 3.

  Further, as shown in FIG. 4, the arrangement of the sealing material 3 is also provided in the large-sized liquid crystal display device 10 that performs display by arranging the plurality of liquid crystal display panels 1 according to the present embodiment in parallel on, for example, two columns and three rows. It is difficult to recognize the boundary between the region and the liquid crystal sealing region, and the adjacent portions of the liquid crystal display panels 1 can be made inconspicuous. Thereby, the arrangement area of the sealing material 3 and the adjacent portion of each liquid crystal display panel 1 can be seen and the appearance is not bad, and the display screen can be looked good.

  Furthermore, by setting the particle size of the coloring material 6 for coloring the sealing material 3 to be equal to or smaller than the gap size between the transparent substrates 2, the particles of the coloring material 6 are evenly arranged between the transparent substrates 2. The sealing material 3 can be made uniform in color as a whole.

  Furthermore, by using a conductive material as the coloring material 6, a predetermined transparent electrode 4 on one transparent substrate 2 and a predetermined transparent electrode on the other transparent substrate 2 through the conductive coloring material 6. 4 can be connected. Thereby, the predetermined transparent electrode 4 between the transparent substrates 2 can be made conductive by the coloring material without using a dedicated conductive material.

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

  For example, in the present embodiment, the sealing material 3 is disposed so as to reach each end of both transparent substrates 2, but is not limited thereto, and is disposed in the vicinity of the ends of both transparent substrates 2. I just need it.

Schematic sectional view showing a liquid crystal display panel according to the present invention The typical enlarged view which shows the boundary of the liquid-crystal enclosure area | region and arrangement | positioning area | region of a sealing material in the liquid crystal display panel of FIG. The graph which shows the spectral spectrum of the selective reflection color and the color of a sealing material in the liquid crystal display panel of FIG. Schematic plan view showing a large display screen constructed by arranging a plurality of the liquid crystal display panels of FIG. 1 in parallel on a plane. Schematic plan view showing the boundary between the liquid crystal sealing area and the sealing material arrangement area in a conventional chiral nematic liquid crystal display panel

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 2 Transparent substrate 2a Edge of transparent substrate 3 Sealing material 5 Chiral nematic liquid crystal 6 Coloring material 8 Light absorption layer

Claims (5)

Electrodes are provided on the inner surfaces of a pair of substrates facing each other, and both the substrates are integrally formed by a sealing material disposed on the inner surfaces of the two substrates, and applied to the inside surrounded by the substrates and the sealing material. In the liquid crystal display panel in which the chiral nematic liquid crystal in which the liquid crystal alignment becomes a planar alignment or a focal conic alignment by voltage is enclosed,
The color of the sealing material has a color difference of 6 or less compared to the selective reflection color obtained by selective reflection in the planar arrangement, or the peak wavelength of the spectral spectrum of the color of the sealing material and the spectral spectrum of the selective reflection color. A liquid crystal display panel, characterized in that a difference from a peak wavelength is 20 nm or less and a glossy lame color.   2. The liquid crystal display panel according to claim 1, wherein a particle diameter of a coloring material for coloring the sealing material into a glossy lame color is equal to or smaller than a gap dimension between the two substrates.   The liquid crystal display panel according to claim 1, wherein a pearl pigment is used as the colorant.   The liquid crystal display according to any one of claims 1 to 3, wherein a conductive material is used as the coloring material, and a predetermined electrode between the two substrates is electrically connected to the conductive coloring material. panel.   A large-sized liquid crystal display device comprising a plurality of liquid crystal display panels according to claim 1 arranged in parallel on a plane.