Abstract:
A liquid crystal display device is provided which includes a substrate having a pixel electrode; and a color filter substrate having a color filter layer on a transparent substrate while having an alignment film formed on an uppermost layer thereof, the substrate and the color filter substrate each having a display region having a plurality of sub-pixels formed thereon, in which the color filter substrate has a liquid crystal layer thickness-adjustment layer formed of a transparent resin layer being partially formed on an inner side of the alignment film; and the liquid crystal layer thickness-adjustment layer has a trench being formed along and between adjacent ones of the sub-pixels, the bottom position of the trench of the liquid crystal layer thickness-adjustment layer being lower than a height of the color filter layer from a surface of the transparent substrate, and the transparent resin layer existing on the bottom of the trench.

Description:
This application claims the benefit of Japanese Patent Application No. 2008-118146, filed on Apr. 30, 2008, and Japanese Patent Application No. 2008-210318, filed on Aug. 19, 2008. The entire disclosures of the prior applications are hereby incorporated by reference herein in their entirety. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of achieving a good display quality, a high aperture ratio and a high display luminance even when a multi-gap layer (liquid crystal layer thickness-adjustment layer) formed of a transparent resin layer is provided on a color filter substrate. 
     2. Related Art 
     In recent years, as a liquid crystal display device used for portable apparatuses typified by cellular phones, a transflective type liquid crystal display devices employing both transmissive and reflective display modes has been widely used. The transflective type liquid crystal display device includes, within each pixel, a transmissive portion (transmissive region) having a transparent electrode and a reflective portion (reflective region) having a reflective layer. In a dark place, a backlight is turned on so that images are displayed using transmissive portions of individual pixels. On the other hand, in a bright place, images are displayed on reflective portions of the individual pixels using an external light without turning on the backlight. Therefore, since electronic apparatuses using the transflective type liquid crystal display device need not always turn on the backlight, an advantage can be obtained that the power consumption thereof can be reduced considerably. 
     The transflective type liquid crystal display device has an optical path difference between the reflective portion and the transmissive portion. This is because in the reflective display mode, light incident from the outside is emitted to the outside in a manner that it makes a round-trip in the liquid crystal panel, while in the transmissive display mode, light from an internal light source such as a backlight passes through the liquid crystal panel to be emitted to the outside. For the purpose of controlling the optical path difference, a method is generally performed in which a so-called multi-gap layer formed of a transparent resin layer is provided to the reflective portion of the transparent substrate so that an optical path in the reflective portion is adjusted by the multi-gap layer so that the length thereof becomes substantially equal to that of an optical path in the transmissive portion. In addition, in a general transmissive type liquid crystal display device, a multi-gap layer formed of a transparent resin layer is often formed in order to protect the color filter layer and improve the flatness. 
     However, when such a multi-gap layer is formed, a step is formed in a boundary region of the reflective portion in which the multi-gap layer exists and the transmissive portion in which the multi-gap layer does not exist. Moreover, when an electrode, a color filter layer, a multi-gap layer, a common electrode, a light shielding film, and the like are formed on a transparent substrate, and an material for alignment film is then applied by a roller, a surplus material for alignment film may remain close to a boundary of the step between the reflective portion and the transmissive portion due to the multi-gap layer, and thus, thickness unevenness of the alignment film may occur. Therefore, in JP-A-2006-267993, there is disclosed a transflective type liquid crystal display device in which a trench is formed in a multi-gap layer for each sub-pixel so as to extend along a signal line thereby to form a pathway for a surplus material for alignment film so that the congestion of the material for alignment film is suppressed. 
     A transflective type liquid crystal display device disclosed in JP-A-2006-267993 will be described with reference to  FIGS. 9 to 11 . In the drawings below used in this specification for explanation purposes, individual layers or individual members are appropriately depicted with different reduced scales in order to make them large enough to be recognized on the drawings but not necessarily proportional to the actual size thereof. 
       FIG. 9  is a cross-sectional view of the transflective type liquid crystal display device disclosed in JP-A-2006-267993 corresponding to one sub-pixel.  FIG. 10  is a fragmentary plan view of a color filter substrate of the transflective type liquid crystal display device disclosed in JP-A-2006-267993.  FIG. 11A  is a cross-sectional view taken along the line XIA-XIA in  FIG. 10 .  FIG. 11B  is a cross-sectional view taken along the line XIB-XIB in  FIG. 10 . 
     The transflective type liquid crystal display device  10 E includes an array substrate (substrate) AR and a color filter substrate CF. The array substrate AR includes an interlayer film  12 , which is formed as necessary on a transparent substrate  11  such as a glass substrate, and a pixel electrode  13  formed thereon. A reflecting plate  14  is provided at the boundary of the interlayer film  12  on the left side of  FIG. 9  and the pixel electrode  13 , and this left portion corresponds to a reflective portion (reflective region)  15 . Moreover, a portion on the right side of  FIG. 9  where the reflecting plate  14  is not provided corresponds to a transmissive portion (transmissive region)  16 . Further, an alignment film  17  is formed on a surface of the pixel electrode  13 . In  FIG. 9 , a switching element, a gate insulating film, a passivation film, and the like are not illustrated. 
     A color filter substrate CF is disposed so as to face an array substrate AR having the pixel electrode  13 , a gap between the array substrate AR and the color filter substrate CF is defined, for example, by a columnar rib (not illustrated), and liquid crystals LC are filled between the substrates. In the color filter substrate CF, as illustrated in  FIG. 10 , color filter layers  19  corresponding to three colors of F (red), G (green) and blue (B) arranged in a stripe form are arranged on a transparent substrate  18 , such as a glass substrate, close to the array substrate AR. Moreover, on the color filter substrate CF, a multi-gap layer (also referred to as an overcoat layer)  20  formed of a transparent resin with a predetermined width is provided to the reflective portion  15  in order to adjust a cell gap between the reflective portion  15  and the transmissive portion  16 . 
     The color filter layers  19  of the three colors R, C and B are formed with a predetermined gap  21   e  between them. The multi-gap layer  20  is formed to be located across adjacent ones of the reflective portions  15 . Furthermore, since the color filter layers  19  of the three colors R, C and B form one pixel (one pixel), a trench  22   e  with a predetermined width is formed in the multi-gap layer  20  for each pixel in a width direction thereof so as to reach the transparent substrate  11 . The trench  22   e  extends along the gap  21   e  of the adjacent color filter layers  19  and has a width larger than the gap  21   e.  In  FIG. 10 , the line denoted by a two-dot chain line is the outline of the multi-gap layer  20  when the trench  22   e  is not formed. Since the multi-gap layer  20  is formed with a resist according to a well-known photolithographic method, the trench  22   e  is formed at the same time with this. On the surfaces of the multi-gap layer  20  and the color filter layers  19 , a common electrode  23  and an alignment film  24  are sequentially formed. 
     Then, liquid crystals LC are filled between the color filter substrate CF and the array substrate AR with the color filter substrate CF being disposed to face the array substrate AR, whereby a transflective type liquid crystal display device  10 E disclosed in JP-A-2006-267993 is obtained. 
     According to the above-described transflective type liquid crystal display device  10 E, although due to presence of the multi-gap layer  20 , a step is formed at a boundary region of the reflective portion  15  and the transmissive portion  16 , because when an material for alignment film is applied by a roller, a surplus material for alignment film may spread into the trench  22   e,  thickness unevenness of the alignment film  24  does not occur. However, since the alignment direction of liquid crystal molecules by the alignment film  24  in the X part (see  FIG. 11A ) of the inclined surfaces of the trench  22   e  is different from the alignment direction in the flat part of the multi-gap layer  20 , the X part becomes an abnormal alignment region of liquid crystal molecules, which is called a disclination. Therefore, although this part of the trench  22   e  is shielded by the light shielding film  25  similar to the gap  21   e  between the adjacent color filter layers  19 , since this part does not contribute to display, there is a problem that the aperture ratio of the liquid crystal display device decreases. Such a problem is particularly so because the step of the trench  22   e  may increase in the case of a display panel configured to perform color display in a transmissive display mode and monochromatic display in a reflective display mode and having no color filter layer on the reflective portion. As a result, the display quality may deteriorate greatly compared with the case of a display panel configured to perform color display in both transmissive display mode and reflective display mode. 
     SUMMARY 
     The invention aims to solve at least part of the above-described problems and can be actualized as a form or an application described below. 
     Application 1 and 2 
     A liquid crystal display device, including: a substrate having a pixel electrode; and 
     a color filter substrate having a color filter layer on a transparent substrate while having an alignment film formed as an uppermost layer thereof, a display region having a plurality of sub-pixels formed thereon, wherein: 
     the color filter substrate has a liquid crystal layer thickness-adjustment layer (multi-gap layer) formed of a transparent resin layer being partially formed so as to overlap with the plurality of sub-pixels; and the liquid crystal layer thickness-adjustment layer has a trench being formed along and between adjacent ones of the sub-pixels, the bottom of the trench of the liquid crystal layer thickness-adjustment layer being lower than a height of the color filter layer from a surface of the transparent substrate, and the transparent resin layer existing on the bottom of the trench. 
     In the liquid crystal display device according to Application 1, the bottom of the trench of the liquid crystal layer thickness-adjustment layer is partly flat. 
     According to such a configuration, when a trench is formed in a liquid crystal layer thickness-adjustment layer formed of a transparent resin layer so that a pathway for a surplus material for alignment film is constructed by the trench, the surplus one of the material for alignment film to be applied on the surface of the transparent resin layer can escape from both sides of the transparent resin layer. Therefore, according to the liquid crystal display device of the invention, it is possible to suppress the disorder of liquid crystal molecule alignment due to the step of the liquid crystal layer thickness-adjustment layer (multi-gap layer). Thus, occurrence of thickness unevenness of the alignment film can be suppressed, and so-called alignment defects such as distortion or non-uniformity of the alignment of the liquid crystal molecules can be reduced, whereby a liquid crystal display device having a good display quality can be obtained. In addition, when the bottom position of the trench of the liquid crystal layer thickness-adjustment layer is lower than the height of the color filter layer from the surface of the transparent substrate and the transparent resin layer exists on the bottom of the trench, the depth of the trench can be decreased compared with the known example. Therefore, it is possible to decrease the area of the inclined portion of the step due to the trench formed in the liquid crystal layer thickness-adjustment layer and to thus decrease the area of a disclination occurring region. Therefore, according to the liquid crystal display device of the invention, it is possible to obtain a liquid crystal display device having a high aperture ratio and a good display quality. 
     Application 3 and 4 
     In the liquid crystal display device according to Application 1, the sub-pixels has a color filter layer of different color in each sub-pixel, and the color filter layer has a predetermined gap between each sub-pixel, wherein the width of the trench is larger than the width of the gap. 
     In the liquid crystal display device according to Application 1, the color filter substrate has a light shielding film being formed so as to overlap with the trench formed in the liquid crystal layer thickness-adjustment layer in plan view. 
     According to such a configuration, the area of a portion of the trench formed in the liquid crystal layer thickness-adjustment layer to be shielded can be decreased compared with the known example. Therefore, according to the liquid crystal display device of the invention, it is possible to obtain a liquid crystal display device having a high aperture ratio and good contrast ratio. 
     Application 5 
     In the liquid crystal display device according to Application 2, the trench formed in the liquid crystal layer thickness-adjustment layer has a width smaller than that of the light shielding film. 
     According to such a configuration, when the width of the trench formed in the liquid crystal layer thickness-adjustment layer is smaller than the width of the light shielding film, it is possible to shield the entire portions of the trench formed in the liquid crystal layer thickness-adjustment layer. Therefore, according to the liquid crystal display device of the invention, it is possible to completely shield the disclination occurring region and thus to obtain a liquid crystal display device having a good display quality. 
     Application 6 
     In the liquid crystal display device according to Application 1, the liquid crystal display device further includes a plurality of pixels each being formed of the plurality of sub-pixels, wherein the trench formed in the liquid crystal layer thickness-adjustment layer is formed for each of the pixels. 
     According to such a configuration, in a liquid crystal display panel having, for example, color filter layers corresponding to three colors of R, Q and B, one pixel (also referred to as one pixel) is formed by three sub-pixels corresponding to respective colors R, G and B. When the trench formed in the liquid crystal layer thickness-adjustment layer is formed for each pixel, it is not necessary to form the trench in the liquid crystal layer thickness-adjustment layer for each of the sub-pixels. Thus, it is not necessary to form a light shielding member for each of the sub-pixels. Therefore, according to the liquid crystal display device of the invention, it is possible to obtain a liquid crystal display device having a high aperture ratio and a high display luminance. 
     Application 7 
     In the liquid crystal display device according to Application 1, the trench formed in the liquid crystal layer thickness-adjustment layer has sidewalls thereof having an inclination angle between 60 and 85 degree with respect to the transparent substrate. 
     According to such a configuration, when the inclination angle of the sidewalls of the trench formed in the liquid crystal layer thickness-adjustment layer with respect to the transparent substrate is equal to or smaller than 60 degree, the area of the alignment disorder region increases, and thus, it is not desirable. When the inclination angle is equal to or greater than 85 degree, the material for alignment film becomes hard to flow therein. The greater the inclination angle of the sidewalls of the trench formed in the liquid crystal layer thickness-adjustment layer with respect to the substrate, the easier it becomes to decrease the area of the sidewalls of the trench where alignment disorder is likely to occur. Thus, it is possible to decrease the area in plan view of the trench to be shielded. Therefore, according to the liquid crystal display device of the invention, it is possible to obtain a liquid crystal display device having a high aperture ratio and a high display luminance. 
     Application 8 and 9 
     In the liquid crystal display device according to Application 1, in each sub-pixel, the color filter layer is not disposed only in a part of the region where the liquid crystal layer thickness-adjustment layer is formed. In the liquid crystal display device according to Application 1, in each sub-pixel, the color filter layer is not disposed over the entire of the region where the liquid crystal layer thickness-adjustment layer is formed. 
     According to such a configuration, when a portion without the color filter layer is provided on a region on which the liquid crystal layer thickness-adjustment layer is formed, it is possible to adjust a difference in absorbance of the color filter layer for each color so that images can look natural to human eyes. Further, the portion without the color filter layer can be used for monochromatic display. Therefore, according to the liquid crystal display device of the invention, it is possible to obtain a liquid crystal display device capable of displaying with a wide range of color tone. 
     Application 10 
     In the liquid crystal display device according to Application 1, each of the plurality of sub-pixels includes a reflective region and a transmissive region, and the liquid crystal layer thickness-adjustment layer is formed in the reflective region. 
     According to such a configuration, since the liquid crystal layer thickness-adjustment layer is formed in the reflective region, it is possible to equalize the optical path length of the reflective portion and the transmissive portion so that an image displayed on the reflective portion has the same color tone as the image displayed on the transmissive portion. In addition, since the liquid crystal display device of the invention is able to perform monochromatic display in the reflective display mode, in this case, the image displayed on the reflective portion can be easily perceived. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a schematic plan view of a color filter substrate of a transflective type liquid crystal display device according to a first embodiment, corresponding to four pixels. 
         FIG. 2A  is a cross-sectional view taken along the line IIA-IIA in  FIG. 1 ,  FIG. 2B  is a cross-sectional view taken along the line IIB-IIB in  FIG. 1 , and  FIG. 2C  is a cross-sectional view taken along the line IIC-IIC in  FIG. 1 . 
         FIG. 3  is a schematic plan view of a color filter substrate of a transflective type liquid crystal display device according to Modification 1, corresponding to four pixels. 
         FIG. 4A  is a cross-sectional view taken along the line IVA-IVA in  FIG. 3 ,  FIG. 4B  is a cross-sectional view taken along the line IVB-IVB in  FIG. 3 , and  FIG. 4C  is a cross-sectional view taken along the line IVC-IVC in  FIG. 3 . 
         FIG. 5  is a cross-sectional view of the portion corresponding to  FIG. 4A  for explaining the relationship between an inclination angle and a light shielding width of an inclined surface of a trench according to Modification 2. 
         FIG. 6  is a schematic plan view of a color filter substrate of a transflective type liquid crystal display device according to Modification 3, corresponding to four pixels. 
         FIG. 7  is a schematic plan view of a color filter substrate of a transflective type liquid crystal display device according to a second embodiment, corresponding to four pixels. 
         FIG. 8  is a cross-sectional view taken along the line VIII-VIII in  FIG. 7 . 
         FIG. 9  is a cross-sectional view of a known transflective type liquid crystal display device corresponding to one sub-pixel. 
         FIG. 10  is a fragmentary plan view of a color filter substrate of the known transflective type liquid crystal display device. 
         FIG. 11A  is a cross-sectional view taken along the line XIA-XIA in  FIG. 10 , and  FIG. 11B  is a cross-sectional view taken along the line XIB-XIE in  FIG. 10 . 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Exemplary embodiments will be described herein below with reference to the accompanying drawings. The following embodiments are merely examples for embodying the invention and clarifying a technical spirit of the invention. This, however, is not intended to restrict the invention to the certain embodiments but other embodiments included in the claims are equally applicable to the invention. In the following descriptions, the same constituent elements as those of the known transflective type liquid crystal display device  10 E illustrated in  FIGS. 9 to 11  will be denoted by the same reference numerals. Moreover, since the array substrate (substrate) of the transflective type liquid crystal display device described in the following embodiments has the same configuration as that of the known liquid crystal display device illustrated in  FIG. 9  except that the color filter layer is not formed in the reflective portion, detailed description thereof will be omitted. 
     First Embodiment 
       FIG. 1  is a schematic plan view of a color filter substrate of a transflective type liquid crystal display device according to a first embodiment, corresponding to four pixels.  FIG. 2A  is a cross-sectional view taken along the line IIA-IIA in  FIG. 1 ,  FIG. 2B  is a cross-sectional view taken along the line IIB-IIB in  FIG. 1 , and  FIG. 2C  is a cross-sectional view taken along the line IIC-IIC in FIG. 
     As illustrated in  FIG. 1 , in a color filter substrate CF of a transflective type liquid crystal display device  10 A according to this embodiment, a reflective portion  15  for performing monochromatic display and a transmissive portion  16  having therein respective color filter layers  19  corresponding to colors R, G and B arranged in a stripe form are arranged in a matrix form. In the transflective type liquid crystal display device  10 A having the color filter layers  19  corresponding to three colors of R, G and B, one pixel is formed by three sub-pixels corresponding to the colors of R, G and B. In addition, in the reflective portion (reflective region)  15 , in order to adjust a cell gap between the reflective portion  15  and the transmissive portion (transmissive region)  16 , a multi-gap layer (liquid crystal layer thickness-adjustment layer)  20  formed of a transparent resin with a predetermined width is provided in a direction intersecting the striped color filter layers  19  of the three colors. The color filter layers  19  of the three colors R, G and B are formed with a predetermined gap  21   a  between them (see  FIG. 2B ). The multi-gap layer  20  is formed to be located across adjacent ones of the reflective portions  15 . Furthermore, since in this example, the color filter layers  19  of the three colors R, C and B form one pixel, a trench  22   a  with a predetermined width is formed for each pixel in a width direction thereof. It should be noted that the trench  22   a  with a predetermined width may be formed for each sub-pixel in a width direction thereof. In this way, a pathway of a surplus material for alignment film is formed, and thus, congestion of the material for alignment film is suppressed. A columnar spacer  28  functions as a spacer for separating the array substrate AR from the color filter substrate CF. Since the columnar spacer  28  can be disposed at any location with the optimum accuracy by a photolithographic method, it is possible to improve display performance compared with a case where beads-like spacers are sprayed. For example, the columnar spacer  28  is disposed on an extended line of a boundary of the color filter layers corresponding to G and B offset from the center of the reflective portion  15 . With this, it is possible to obtain a uniform cell thickness in the reflective portion  15  and make the columnar spacer  28  hard to be seen. 
     The bottom of the trench  22   a  formed in the multi-gap layer  20  according to this embodiment is partly flat. As illustrated in  FIGS. 2A and 2C , differently from the trench  22   e  formed in the multi-gap layer  20  of the known transflective type liquid crystal display device  10 E, the bottom position of the trench  22   a  is lower than a height of the color filter layer  19  of the transmissive portion  16  from a surface of the transparent substrate  18 , and a transparent resin layer exists on the bottom of the trench  22   a.  Here, a height of the bottom of the trench  22   a  of the multi-gap layer  20  from the surface of the transparent substrate  18  is defined as h 1 , a height of a top surface of the multi-gap layer  20  from said surface is defined as h 2 , and a height of the color filter layer  19  from said surface is defined as h 3 , respectively. Then, because the multi-gap layer  20  has a function of adjusting the cell gap between the reflective portion  15  and the transmissive portion  16 , the multi-gap layer  20  needs to satisfy a relationship of h 2 &gt;h 3 . 
     On the other hand, in the transflective type liquid crystal display device  10 A according to this embodiment, the height h 1  of the bottom of the trench  22   a  of the multi-gap layer  20  from the surface of the transparent substrate  13  is lower than the height h 2  of the color filter layer  19  and satisfies a relationship of h 3 &gt;h 1 . In addition, since the transparent resin layer exists on the bottom of the trench  22   a,  a relationship of h 1 &gt;0 is satisfied. That is, in the transflective type Liquid crystal display device  10 A according to this embodiment, a relationship of h 2 &gt;h 3 &gt;h 0 &gt;0 is satisfied. 
     On the other hand, in the known transflective type liquid crystal display device  10 E, since the transparent resin layer does not exist on the bottom of the trench  22   e  formed in the multi-gap layer  20  (see  FIG. 11A ), a relationship of h 1 =0 is satisfied. Therefore, when the condition of h 2 &gt;h 3 &gt;h 1 &gt;0 is satisfied as in the case of this embodiment, it is possible to decrease the step of the trench  22   a  formed in the multi-gap layer  20  to be smaller than the step of the trench  22   e  of the known transflective type liquid crystal display device  1 E. Accordingly, in accordance with the transflective type liquid crystal display device  10 A according to this embodiment, particularly in a display panel configured to perform color display in a transmissive display mode and monochromatic display in a reflective display mode, it is possible to decrease the area of an inclined portion having the step due to the trench  22   a  formed in the multi-gap layer  20 . Consequently, it is possible to decrease the area of a disclination occurring region and to thus obtain a liquid crystal display device having a good display quality. 
     Modification 1 
     Although the transflective type liquid crystal display device  10 A according to the above embodiment has been described with respect to an example where the bottom of the trench  22   a  formed in the multi-gap layer  20  is partly flat in a row direction, the trench may have a V shape in cross-sectional view as long as the transparent resin layer exists on the bottom of the trench and the condition of h 2 &gt;h 3 &gt;h 0 &gt;0 is satisfied.  FIG. 3  is a schematic plan view of a color filter substrate of a transflective type liquid crystal display device according to this modification, corresponding to four pixels.  FIG. 4A  is a cross-sectional view taken along the line IVA-IVA in  FIG. 3 ,  FIG. 4B  is a cross-sectional view taken along the line IVB-IVB in  FIG. 3 , and  FIG. 4C  is a cross-sectional view taken along the line IVC-IVC in  FIG. 3 . Since a transflective type liquid crystal display device  10 B according to this modification has the same configuration as that of the transflective type liquid crystal display device  10 A according to the above embodiment, except that a trench  22   b  formed in the multi-gap layer  20  has a V shape in cross-sectional view, the same constituent elements as those of the transflective type liquid crystal display device  10 A according to the above embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted. In the case of the transflective type liquid crystal display device  10 B according to this modification, it is possible to obtain the same operation and effect as the transflective type liquid crystal display device  10 A according to the above embodiment. 
     Modification 2 
     The trenches  22   a  and  22   b  formed in the multi-gap layer  20  have inclined portions (sidewalls) thereof having an inclination angle of preferably 60 to 85 degree with respect to the transparent substrate  18 . When the inclination angle of the inclined portions of the trenches  22   a  and  22   b  formed in the multi-gap layer  20  with respect to the transparent substrate  18  is equal to or smaller than 60 degree, the area of an alignment disorder region increases, and thus, it is not desirable. When the inclination angle is greater than 85 degree, the material for alignment film becomes hard to flow therein. 
       FIG. 5  is a cross-sectional view of the portion corresponding to  FIG. 4A , for explaining the relationship between an inclination angle and a light shielding width of an inclined surface of a trench. For example, as illustrated in  FIG. 5 , when a width of a portion of the light shielding film  25  to be shielded, corresponding to an inclined portion of the trench having a larger inclination angle (θ 1 ) with respect to the transparent substrate  18  is defined as W 1  and a width of a portion of the light shielding film  25  to be shielded, corresponding to an inclined portion of the trench having a smaller inclination angle (θ 2 ) is defined as W 2 , a relationship of W 1 &lt;W 2  is always satisfied. Therefore, particularly, when the inclination angle is increased close to 85 degree, the area in plan view of the inclined portions of the trenches  22   a  and  22   b  is relatively decreased. Thus, the area of a region where alignment of liquid crystal molecules is disordered is decreased, whereby the area of a disclination occurring region can be decreased. Furthermore, since the area of a region to be shielded by the light shielding film  25  is decreased, it is possible to decrease the width of the light shielding film  25 , so that an aperture ratio is increased, and a liquid crystal display device having a high display luminance can be obtained. Here, it is to be noted that the light shielding film  25  between the reflective portion  15  and the transmissive portion  16  is not always necessary. In this way, the aperture ratio can be increased, and a liquid crystal display device having a high display luminance can be obtained. 
     Modification 3 
     Although the above embodiment has been described with respect to a case where the sub-pixels of colors R, G and B are arranged in a stripe form, the above embodiment is not limited to this but may employ other arrangement structures. 
       FIG. 6  is a schematic plan view of a color filter substrate of a transflective type liquid crystal display device according to this modification, corresponding to four pixels. For example, in lieu of such a strip arrangement as illustrated in  FIG. 1 , a delta arrangement of the transflective type liquid crystal display device  10 C illustrated in  FIG. 6  or a non-illustrated mosaic arrangement may be employed. 
     Modification 4 
     The color filter layers are not limited to three colors of R, G and B. More colors including the three colors are applicable. For example, the color filter layers may be formed to correspond to four colors of R, G, B and C (cyan). In this way, images can be reproduced with a larger number of colors, i.e., at least four primary colors, than the known example capable of reproducing images with three primary colors. As a result, the color gamut is increased and a liquid crystal display device having a high display luminance can be obtained. 
     Modification 5 
     The width of the trench  22   a  formed in the multi-gap layer  20  is larger than the width of the gap  21   a  of the color filter layers  19 . For example, when the width of the gap  21   a  of the color filter layers  19  is defined as L 1  and the width of the trench  22   a  formed in the multi-gap layer  20  is defined as L 2 , a relationship of L 1 &lt;L 2  is satisfied. It is, however, preferable that the two widths are substantially equal when the aperture ratio of the reflective portion  15  corresponding to the region of the multi-gap layer  20  is considered. 
     Second Embodiment 
     The first embodiment employs a transflective type liquid crystal display device configured to perform color display in a transmissive display mode and monochromatic display in a reflective display mode. To the contrary, this embodiment is different from the first embodiment in that it employs a transflective type liquid crystal display device configured to perform color display in both transmissive display mode and reflective display mode. This embodiment will be described in detail with reference to the drawings. Description of the same elements and the like as those of the first embodiment will be omitted or simplified. 
       FIG. 7  is a schematic plan view of a color filter substrate of a transflective type liquid crystal display device according to this embodiment, corresponding to four pixels.  FIG. 8  is a cross-sectional view taken along the line VIII-VIII in  FIG. 7 . As illustrated in  FIGS. 7 and 8 , in a color filter substrate CF of a transflective type liquid crystal display device  10 D according to this embodiment, a reflective portion  15  having therein respective color filter layers  30  corresponding to colors R, G and B arranged in a stripe form and a transmissive portion  16  having therein respective color filter layers  30  corresponding to colors R, G and B arranged in a stripe form are arranged in a matrix form. In the transflective type liquid crystal display device  10 D, among colored layers of colors R, G and B constituting the color filter layers  30  of the reflective portion  15 , a region having no coloring material (non-colored region) is provided within at least one colored layer. In a transmissive type liquid crystal display device employing such a configuration, for example, by allowing the size of the non-colored regions in the respective colored layers of colors R, G and B to be different depending on the spectral characteristics of backlights, it is possible to control color balance. For example, by leaving 70 percent of the colored region for R, 30 percent of the colored region for G, and 75 percent of the colored region for B, it is possible to control color balance. When the above configuration is applied to a transflective type liquid crystal display device, by providing the non-colored region in a reflective display region where light passes across the colored layer twice, for example, it is possible to decrease a difference in contrast of colors between reflective display mode and transmissive display mode. In the case of the transflective type liquid crystal display device  10 D according to this embodiment, it is possible to obtain the same operation and effect as the transflective type liquid crystal display device  10 A according to the above embodiment. 
     While the above embodiments have been described with respect to the examples of a transflective type liquid crystal display device configured to perform color display n a transmissive display mode and monochromatic display in a reflective display mode and a transflective type liquid crystal display device configured to perform color display in both transmissive display mode and reflective display mode, the invention can be applied to a transmissive type liquid crystal display device as long as a multi-gap layer and steps or inclined portions formed by the multi-gap layer exist.