JP2006337590A - Color liquid crystal display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color liquid crystal display panel of which the thickness of a liquid crystal layer interposed between a pair of substrates in a display region is further uniformized. <P>SOLUTION: A color filter layer 19 has a dummy color filter 19D which corresponds to overlapping portions L with a light shielding layer 18 of respective color filters 19R, 19G, 19B, squeezed out of dot conforming regions S onto the light shielding layer 18, and which is formed with a height nearly equal to that of the overlapping portions L and with a frame shape on the light shielding layer 18 arranged outside the display region. The dummy color filter 19D is arranged on the outside of the display region so as to be aligned and extended over at least two dots width. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a color liquid crystal display panel that performs full dot color display using a color filter.

  In a liquid crystal display device that performs full-dot color display, each pixel (pixel) is divided into three sub-pixels, and color filters corresponding to the three primary colors of red (R), green (G), and blue (B) are provided for each pixel. A color liquid crystal display panel arranged in the above is used. Further, in the color liquid crystal display panel, a light-shielding layer that shields light between the dots in the display area is provided in order to prevent light color mixing between the color filters.

  By the way, in the conventional liquid crystal display device, when an image is displayed on the color liquid crystal display panel, display unevenness may occur around the display area of the color liquid crystal display panel (see, for example, Patent Document 1). ). This is because the flattening layer 103 covering the surface of the light shielding layer 101 and the color filter layer 102 formed on the substrate 100 in the vicinity of the boundary between the display region and the non-display region of the color liquid crystal display panel shown in FIG. This is because a portion having a non-uniformity occurs. Specifically, in the display area, an overlapping portion L ′ of the color filter 102 protruding from the dot corresponding area S ′ corresponding to each dot on the light shielding layer 101 with the light shielding layer 101 is generated. For this reason, in the vicinity of the boundary between the display area and the non-display area, there is a portion where the height of the planarization layer 103 decreases from the display area toward the non-display area.

Therefore, when a portion where the height of the flattening layer 103 is uneven is generated in the display area of the color liquid crystal display panel, the liquid crystal layer sandwiched between the pair of substrates of the color liquid crystal display panel. Since the thickness (also referred to as a gap) in the display area becomes non-uniform, the above-described display unevenness occurs around the display area.
Japanese Patent Laid-Open No. 1-269917

  Therefore, the present invention has been proposed in view of such a conventional situation, and a color that makes it possible to further uniform the thickness in the display region of the liquid crystal layer sandwiched between a pair of substrates. An object is to provide a liquid crystal display panel.

In order to achieve this object, the invention according to claim 1 of the present invention includes any one of a pair of substrates disposed opposite to each other, a liquid crystal layer sandwiched between the pair of substrates, and a pair of substrates. A light-shielding layer that is formed on one inner surface and divides a dot-corresponding region corresponding to a dot in the display region; a single-layer portion disposed in the dot-corresponding region; and an overlapping portion disposed on the light-shielding layer. A color liquid crystal display panel comprising a color filter layer having a light shielding layer and a planarizing layer covering a surface on which the light shielding layer and the color filter layer are formed, on the light shielding layer provided outside the display region, A color liquid crystal display panel characterized in that a frame-like dummy color filter having substantially the same height as the overlapping portion is provided.
The invention according to claim 2 of the present invention is the color liquid crystal display panel according to claim 1, characterized in that dummy color filters are provided side by side for at least two dots outside the display area.

  As described above, according to the present invention, the surface of the flattening layer in the display region can be further flattened, and thus the thickness of the liquid crystal layer sandwiched between the pair of substrates in the display region is further increased. It can be made uniform.

  In addition, according to the present invention, when the color liquid crystal display panel is manufactured, such a dummy color filter can be formed by the same process as the color filter in the display region, which is very advantageous in manufacturing.

  Hereinafter, a color liquid crystal display panel to which the present invention is applied will be described in detail with reference to the drawings. In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.

  A color liquid crystal panel to which the present invention is applied is used in a liquid crystal display device 1 that performs full dot color display as shown in FIG. Specifically, the liquid crystal display device 1 includes a color liquid crystal display panel 10 to which the present invention is applied, polarizing plates 2 and 3 disposed on the back side and the front side across the color liquid crystal display panel 10, and a back side. And a backlight 4 disposed on the opposite side of the color liquid crystal display panel 10 with the polarizing plate 2 interposed therebetween.

  Among them, the pair of polarizing plates 2 and 3 is a color liquid crystal display panel 10 so as to perform display in a normally black mode that gives a black level when no voltage is applied, or in a normally white mode that gives a white level when no voltage is applied. The mutual polarization directions with respect to are set.

  The backlight 4 includes a light guide plate 4a made of a flat transparent acrylic resin or the like, and a light source 4b made of a cathode fluorescent tube, an LED (Light Emitting Diode) or the like, and light emitted from the light source 4b. Is emitted to the back side of the color liquid crystal display panel 10 while surface emitting light with the light guide plate 4a.

  The color liquid crystal display panel 10 includes a back side substrate 11 and a front side substrate 12 which are disposed to face each other, and a liquid crystal layer 13 sandwiched between the back side substrate 11 and the front side substrate 12. . The back side substrate 11 and the front side substrate 12 are made of transparent glass or the like. Further, between the back side substrate 6 and the front side substrate 7, the facing distance between the back side substrate 6 and the front side substrate 7 is uniformly maintained by the spacers 14 dispersed in the liquid crystal layer 13, and the peripheral portions are sealed with the sealing material 15. Has been.

  Transparent electrodes 16 and 17 are provided on the mutually opposing surfaces (inner surfaces) of the back side substrate 11 and the front side substrate 12, respectively. The transparent electrodes 16 and 17 are made of a transparent conductive material such as ITO (Indium-Tin Oxide). Although not shown, alignment films are provided on the inner surfaces of the rear substrate 11 and the front substrate 12 to cover the transparent electrodes 16 and 17, respectively. These alignment films control the alignment of the liquid crystal layer 13. For example, when a TN (Twisted Nematic) system is adopted, the alignment films are aligned in a state where the liquid crystal molecules of the liquid crystal layer 13 are twisted by about 90 °. Is done. Further, when an STN (Super Twisted Nematic) system is adopted, the liquid crystal molecules of the liquid crystal layer 13 are aligned in a state twisted by about 180 ° to 270 ° by these alignment films.

  The liquid crystal layer 13 is made of, for example, nematic liquid crystal containing an optical rotatory substance. The alignment state of the liquid crystal layer 13 changes in response to an electric field due to the dielectric anisotropy of the liquid crystal molecules. Therefore, the polarization state of the light passing through the color liquid crystal display panel 10 can be changed by switching the driving voltage applied between the transparent electrodes 16 and 17 to an on or off state.

  The color liquid crystal display panel 10 employs, for example, a passive matrix driving method. In this case, the transparent electrodes 16 and 17 are arranged in a plurality of stripes at predetermined intervals, respectively, and have a structure in which the transparent electrodes 16 and 17 are arranged orthogonally between the back substrate 11 and the front substrate 12. .

  In addition, dots are formed at positions where these transparent electrodes 16 and 17 intersect, and a plurality of these dots are arranged in a matrix, thereby forming a display area of the color liquid crystal display panel 10 as a whole. ing. Further, a drive driver (not shown) for controlling a drive voltage applied between the electrodes 16 and 17 of each dot is provided outside the display area. The drive driver controls the lighting of each dot, whereby an arbitrary image can be displayed in full dots on the display area.

  The color liquid crystal display panel 10 to which the present invention is applied is not necessarily limited to the one adopting the above-described passive matrix drive method, and may be one adopting an active matrix drive method (for example, TFT method). Good. In this case, one of the transparent electrodes 16 and 17 is a solid electrode formed over the entire surface of the substrate, and the other is a plurality of pixel electrodes arranged in a matrix corresponding to each dot. Further, each dot D is provided with an active element such as a TFT (Thin Film Transistor) to control lighting of each dot.

  As shown in FIGS. 2 and 3, the color liquid crystal display panel 10 to which the present invention is applied has dots corresponding to the dots in the display area on the surface (inner surface) facing the liquid crystal layer 13 of the back substrate 11. The light shielding layer 18 that defines the corresponding region S, and the color filters 19R corresponding to the three primary colors of red (R), green (G), and blue (B) are provided in each dot corresponding region S partitioned by the light shielding layer 18. The color filter layer 19 in which 19G and 19B are periodically arranged and the planarization layer 20 covering the surface on which the light shielding layer 18 and the color filter layer 19 are formed are provided. The transparent electrode 16 is formed on the surface flattened by the flattening layer 20.

  The display area is partitioned in a checkered pattern by the stripe-shaped light shielding layer 18, and each rectangular area partitioned by the light shielding layer 18 forms a dot corresponding area S corresponding to each dot. ing. In the color liquid crystal display panel 10, the stripe-shaped light shielding layer 18 shields light between the dots in the display region, thereby preventing light from being mixed from adjacent dots, thereby improving the contrast. Can do. Further, a solid light shielding layer 18 surrounding the display area in a frame shape is provided in the non-display area outside the display area.

  In each dot-corresponding region S partitioned by the light shielding layer 18, any one of the red (R), green (G), and blue (B) color filters 19R, 19G, and 19B is a single layer portion. It is formed to become. Each color filter 19R, 19G, 19B has a structure periodically arranged in a stripe shape. In this color liquid crystal display panel 10, one unit pixel (referred to as a pixel) is constituted by three adjacent dots (referred to as sub-pixels) in which red, green, and blue color filters 19R, 19G, and 19B are arranged. ing. And the display color of each pixel is controlled by controlling the drive voltage applied between the said electrodes 16 and 17 for every three dots of each pixel.

  The color filter layer 19 has a configuration in which the color filters 19R, 19G, and 19B are periodically arranged in a stripe shape, but is not necessarily limited to such a configuration. 19R, 19G, and 19B may be arranged periodically in a mosaic pattern.

  Incidentally, the color liquid crystal display panel 10 to which the present invention is applied is provided with a dummy color filter 19D as shown in FIGS. 4A and 4B in order to further flatten the surface of the flattening layer 20 in the display region. Yes. This dummy color filter 19D corresponds to the overlapping portion L of each of the color filters 19R, 19G, 19B protruding from the dot corresponding area S on the light shielding layer 18 with the light shielding layer 18, and the light shielding layer in the non-display area. 18 is provided with a dummy color filter 19D formed in a rectangular frame shape at substantially the same height as the overlapping portion L.

  The dummy color filter 19D is provided outside the display area and arranged at least for two dots. Specifically, on the light shielding layer 18 in the non-display area that surrounds the periphery of the display area, a dummy color filter 19D for two dots arranged at the same interval as the arrangement of the dot corresponding areas S in the display area is provided. Yes.

  In this case, the lower position of the flattening layer 20 is shifted from the vicinity of the boundary between the display region and the non-display region toward the non-display region, so that the surface of the flattening layer 20 in the display region is flattened as compared with the conventional case. be able to.

  Thereby, in the color liquid crystal display panel 10 to which the present invention is applied, the thickness in the display region of the liquid crystal layer 13 sandwiched between the pair of substrates 11 and 12 can be made more uniform. Therefore, in the liquid crystal display device 1 using the color liquid crystal display panel 10, it is possible to prevent display unevenness from occurring around the display area when an image is displayed.

  By the way, when such a dummy color filter 19D is provided for only one dot outside the display area, the level of the flattening layer 20 can be shifted to the outside of the display area. This is insufficient for flattening in the display area. On the other hand, when the dummy color filter 19D is provided for two dots or more outside the display area, the position where the planarization layer 20 is lowered can be appropriately shifted outside the display area.

  In addition, if the number of dummy color filters 19D is increased, the position where the planarizing layer 20 is lowered can be shifted to the outside of the display area as a matter of course. However, when the number of dummy color filters 19D is increased, a portion that does not contribute to the flattening in the display region of the flattening layer 20 gradually appears. 2 pixels) of dummy color filters 19D are preferably arranged outside the display area. That is, the dummy color filter 19D is preferably arranged side by side outside the display area in the range of 2 to 6 dots.

  From the above, in the color liquid crystal display panel 10 to which the present invention is applied, the dummy color filter 19D for at least 2 dots, preferably 6 dots (for 2 pixels) is arranged side by side outside the display area, so that it is flat. The planarization of the display layer 20 in the display region can be performed more effectively.

  Further, in the color liquid crystal display panel 10 to which the present invention is applied, such a dummy color filter 19D can be formed by the same process as the color filters 19R, 19G, and 19B.

  Specifically, when the color liquid crystal display panel 10 is manufactured, after the light shielding layer 18 is formed on the back side substrate 11 described above, the application, exposure, and development of the color filters 19R, 19G, and 19B are performed in this order. Is repeated three times to form a color filter layer 19 in which striped color filters 19R, 19G, and 19B are periodically arranged. The dummy color filter 19D is formed simultaneously with the color filters 19R, 19G, and 19B by forming a pattern corresponding to the dummy color filter 19D in the mask pattern when the color filters 19R, 19G, and 19B are exposed. be able to.

  As described above, when the color liquid crystal display panel 10 is manufactured, such a dummy color filter 19D can be formed by the same process as the color filters 19R, 19G, and 19B in the display region, which is very advantageous in manufacturing. is there.

  Further, the color liquid crystal display panel 10 to which the present invention is applied may have a structure as shown in FIG. 5, for example. Specifically, in the color liquid crystal display panel 10 shown in FIG. 5, the light shielding layer 18 between the adjacent dot corresponding regions S has one color filter 19R, 19G, 19B protruding from the adjacent dot corresponding regions S. And only overlap.

  Also in this case, the dummy color filter 19D formed at substantially the same height as the overlapping portion L corresponding to the overlapping portion L of each color filter 19R, 19G, 19B protruding from the dot corresponding region S with the light shielding layer 18. By arranging at least two dots on the outside of the display area, the surface of the planarization layer 20 in the display area can be further flattened.

  In addition, the color liquid crystal display panel 10 to which the present invention is applied has a reflector on the back side of the panel, for example, in addition to a transmissive liquid crystal display device that displays images by irradiating light on the back side of the panel. Or by forming a reflective film on the back side substrate of the panel, it can also be used in a reflective liquid crystal display device that performs image display using external light reflection.

  The color liquid crystal display panel 10 to which the present invention is applied is not limited to the configuration in which the light shielding layer 18, the color filter layer 19, and the planarizing layer 20 are provided on the inner surface of the back side substrate 11. 19 and 20 may be provided on the inner surface of the front substrate 12. Also in this case, by arranging the dummy color filter 19D, the same effect as in the case of the above configuration can be obtained.

FIG. 1 is a cross-sectional view showing an example of a liquid crystal display device using a color liquid crystal display panel to which the present invention is applied. FIG. 2 is an enlarged plan view showing the vicinity of the boundary between the display area and the non-display area of the color liquid crystal display panel shown in FIG. FIG. 3 is an enlarged sectional view showing the vicinity of the boundary between the display area and the non-display area of the color liquid crystal display panel shown in FIG. 4 is a diagram showing a state of the planarization layer in the vicinity of the boundary between the display area and the non-display area of the color liquid crystal display panel shown in FIG. 1, wherein A is a plan view thereof, and B is a sectional view thereof. It is. FIG. 5 is a cross-sectional view showing another configuration of the color liquid crystal display panel shown in FIG. FIG. 6 is a cross-sectional view showing the state of the planarization layer in the vicinity of the boundary between the display area and the non-display area of the conventional color liquid crystal display panel.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device 2, 3 ... Polarizing plate 4 ... Backlight 10 ... Color liquid crystal display panel 11 ... Back side substrate 12 ... Front side substrate 13 ... Liquid crystal layer 18 ... Light shielding layer 19 ... Color filter layer 19R, 19G, 19B ... Color filter 19D ... Dummy color filter 20 ... Flattening layer

Claims (2)

A pair of substrates disposed opposite each other;
A liquid crystal layer sandwiched between the pair of substrates;
A light-shielding layer that is formed on the inner surface of one of the pair of substrates and that defines a dot corresponding area corresponding to a dot in the display area;
A color filter layer having a single layer portion disposed in the dot corresponding region and an overlapping portion disposed on the light shielding layer;
A color liquid crystal display panel comprising a planarization layer covering a surface on which the light shielding layer and the color filter layer are formed,
A color liquid crystal display panel, wherein a frame-like dummy color filter having a height substantially the same as the overlapping portion is provided on a light shielding layer provided outside the display area.   The color liquid crystal display panel according to claim 1, wherein the dummy color filter is provided outside the display area so as to be arranged at least for two dots.

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