Patent Publication Number: US-2022229332-A1

Title: Liquid crystal display device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of PCT Application No. PCT/JP2020/038780, filed Oct. 14, 2020, and based upon and claiming the benefit of priority from Japanese Patent Application No. 2019-189202, filed Oct. 16, 2019, the entire contents of all of which are incorporated herein by reference. 
    
    
     FIELD 
     The present invention relates to a liquid crystal display device capable of transmission display and reflection display. 
     BACKGROUND 
     A transflective liquid crystal display device capable of displaying images in both transmission mode and reflection mode has been known as a liquid crystal display device that is improved in outdoor visibility. In the transflective liquid crystal display device, a reflective metal film provided inside a liquid crystal cell is patterned to form a reflection area and a transmission area and combine reflection display by the reflection area and transmission display by the transmission area. In addition, a transparent step film or the like is provided in the reflection area to vary a cell gap (multigap) between the reflection area and the transmission area and thus optimize the optical characteristics (patent literature 1 (Jpn. Pat. Appln. KOKAI Publication No. 2003-262852) and patent literature 2 (Jpn. Pat. Appln. KOKAI Publication No. 2003-270627), for example). 
     In the liquid crystal display device having a multigap, steps are formed between the reflection area and the transmission area to easily cause an alignment failure at the boundary of the steps and a light leakage from the boundary. Thus, the following problems arise. The alignment failure makes an image rough and the light leakage reduces the contrast of display. In addition, when a user applies pressure to a display area with his or her finger or a pen (when the display area is pressed), the alignment failure is continued and the traces of the pressure will be left (patent literature 3 (International Publication No. 2005/111708)). 
     In order to solve the above problems, various methods are proposed, such as separating a pixel electrode (forming a slit) in a step portion between a reflection area and a transmission area in one pixel to form the reflection area and the transmission area independently (patent literature 4 (Japanese Patent No. 3900123)), controlling the height (patent literature 5 (Japanese Patent No. 4432371)) and inclination (patent literature 6 (Japanese Patent No. 3903980)) of a protrusion formed in the transmission area to control alignment, controlling alignment by an opening (hole) of the electrode in the reflection area of the electrode and a protrusion in the transmission area (patent literature 7 (Japanese Patent No. 4182748)), forming a recess in the reflection area and placing the protrusion in the recess (patent literature 8 (Japanese Patent No. 4123208)), and the like. 
     However, the following problems arise. When a pixel electrode is separated by a slit between a reflection area and a transmission area in one pixel and when the alignment of the reflection area is controlled by a protrusion, an opening (hole) of the electrode and the like, the reflection area needs to be sufficiently large (for example, the area of the reflection area is 30% or more larger than that of the pixel electrode) and the brightness of transmission display is lowered. Similarly, even when the alignment is controlled by the height and shape of a protrusion in the transmission area without increasing the area of the reflection area, the height and area of the protrusion are increased to lower the brightness of transmission display. 
     SUMMARY 
     According to an aspect of the present invention, there is provided a liquid crystal display device comprising: 
     first and second substrates; 
     a liquid crystal layer interposed between the first and second substrates and set in vertical alignment (VA) when no electric field is applied; 
     a switching element provided on the first substrate; 
     a connection electrode provided on the first substrate, connected to the switching element, and extending in a first direction; 
     a first reflection film provided above the switching element with an insulating film therebetween; 
     a first pixel electrode provided above the first reflection film with an insulating film therebetween and overlapping the first reflection film in planar view; 
     a second pixel electrode located adjacent to the first pixel electrode in the first direction; 
     first and second contacts which connect the first and second pixel electrodes to the connection electrode; 
     a first thickness adjusting layer provided on the second substrate and overlapping the first reflection film in planar view; 
     a common electrode provided on the second substrate and the first thickness adjusting layer; and 
     first and second protrusions provided on the common electrode and corresponding to the first and second pixel electrodes, respectively, 
     wherein the first protrusion is located to shift toward the first thickness adjusting layer from a center of the first pixel electrode in the first direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a liquid crystal display device according to a first embodiment. 
         FIG. 2  is a plan view of a liquid crystal display panel according to the first embodiment. 
         FIG. 3  is a sectional view of the liquid crystal display panel taken along line A-A′ of  FIG. 2 . 
         FIG. 4  is a schematic diagram illustrating the conditions of the liquid crystal display panel. 
         FIG. 5  is a graph showing the relationship between a distance between a thickness adjusting layer and a protrusion and surface pressure recovery time. 
         FIG. 6  is a modification to the graph of multigap shown in  FIG. 5 . 
         FIG. 7  is a schematic diagram of a liquid crystal display panel according to a modification. 
         FIG. 8  is a plan view of a liquid crystal display panel according to a second embodiment. 
         FIG. 9  is a sectional view of the liquid crystal display panel taken along line A-A′ of  FIG. 8 . 
         FIG. 10  is a schematic diagram of the liquid crystal display panel according to the second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments will be described below with reference to the drawings. The drawings are schematic or conceptual, and the dimension, ratio, or the like in each of the drawings is not necessarily the same as the actual one. The drawings may include portions that differ in the relationship in dimensions and in the ratio even though the portions are the same. Some of the embodiments exemplify a device and a method for embodying the technical concept of the present invention, and the technical concept is not specified by the shape, configuration, placement, etc. of the components. In the following descriptions, the elements having the same function and configuration are denoted by the same sign and their descriptions will be repeated only when necessary. 
     [1] FIRST EMBODIMENT 
     [1-1] Overall Configuration of Liquid Crystal Display Device 
       FIG. 1  is a block diagram of a liquid crystal display device  1  according to a first embodiment of the present invention. The liquid crystal display device  1  includes a liquid crystal display panel  2 , a backlight (illumination device)  3 , a scan line driving circuit  4 , a signal line driving circuit  5 , a common electrode driver  6 , a voltage generation circuit  7  and a control circuit  8 . 
     The liquid crystal display panel  2  includes a pixel array in which a plurality of pixels PX are arranged in a matrix. The liquid crystal display panel  2  includes a plurality of scan lines GL 1  to GLm each extending in the row direction and a plurality of signal lines SL 1  to SLn each extending in the column direction. The letters “m” and “n” each indicate an integer of two or more. Pixels PX are placed in intersection areas between the scan and signal lines GL and SL. 
     The backlight  3  is a surface light source that irradiates the back surface of the liquid crystal display panel  2  with light. As the backlight  3 , for example, a direct type or a side light (edge light) type LED backlight is used. 
     The scan line driving circuit  4  is electrically connected to the scan lines GL. Upon receiving a control signal from the control circuit  8 , the scan line driving circuit  4  sends scan signals to the liquid crystal display panel  2  to turn on/off the switching elements included in the pixels PX. 
     The signal line driving circuit  5  is electrically connected to the signal lines SL. The signal line driving circuit  5  receives a control signal and display data from the control circuit  8 . In response to the control signal, the signal line driving circuit  5  sends gradation signals (drive voltages) corresponding to the display data to the liquid crystal display panel  2 . 
     The common electrode driver  6  generates a common voltage Vcom and applies it to the common electrode in the liquid crystal display panel  2 . The voltage generation circuit  7  generates various voltages necessary for the operation of the liquid crystal display device  1  and applies them to the respective circuits. 
     The control circuit  8  collectively controls the operation of the liquid crystal display device  1 . The control circuit  8  externally receives image data DT and control signal CNT. Based on the image data DT, the control circuit  8  generates various control signals and sends the control signals to each of the circuits. 
     [1-2] Configuration of Liquid Crystal Display Panel  2   
     The liquid crystal display panel  2  according to the present embodiment is a transflective liquid crystal display panel capable of transmission display and reflection display. 
       FIG. 2  is a plan view of the liquid crystal display panel  2  according to the first embodiment.  FIG. 3  is a sectional view of the liquid crystal display panel  2  taken along line A-A′ in  FIG. 2 . In  FIG. 2 , a portion corresponding to one pixel is extracted and actually, a plurality of pixels each corresponding to the pixel shown in  FIG. 2  are arranged in a matrix. 
     The liquid crystal display panel  2  includes a TFT substrate  10  on which a switching element (TFT), a pixel electrode and the like are formed, and a color filter substrate (CF substrate)  11  on which a color filter, a common electrode and the like are formed and which is opposed to the TFT substrate  10 . Each of the TFT and CF substrates  10  and  11  is configured by a transparent substrate (for example, a glass substrate or a plastic substrate). 
     The liquid crystal layer  12  is filled between the TFT and CF substrates  10  and  11 . Specifically, the liquid crystal layer  12  is sealed in a display area surrounded by the TFT and CF substrates  10  and  11  and a sealing member (not shown). The sealing member is made of an ultraviolet-curing resin, a thermosetting resin, an ultraviolet-heat combination-type curing resin, or the like, and is applied to the TFT substrate  10  or the CF substrate  11  in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. 
     The liquid crystal materials of the liquid crystal layer  12  vary in optical characteristics as the alignment of liquid crystal molecules is manipulated in accordance with an electric field applied between the TFT and CF substrates  10  and  11 . The liquid crystal display panel  2  of the present embodiment is set in a vertical alignment (VA) mode using a VA type liquid crystal. That is, a negative (N-type) nematic liquid crystal having negative dielectric anisotropy is used as the liquid crystal layer  12 . The liquid crystal layer  12  is vertically aligned in an initial state. When no voltage (no electric field) is applied to the liquid crystal layer  12 , the major axes (directors) of liquid crystal molecules is aligned substantially vertically with respect to the main surface of the substrate. When a voltage is applied to the liquid crystal layer  12 , the major axes of the liquid crystal molecules tilt toward the horizontal direction with respect to the main surface of the substrate. 
     First is a description of the configuration alongside the TFT substrate  10 . A switching element  13  is provided for each pixel on the liquid crystal layer  12  side of the TFT substrate  10 . As the switching element  13 , for example, a thin film transistor (TFT) and an n-channel TFT are used. As will be described later, the TFT  13  includes a gate electrode functioning as a scan line, a gate insulating film provided on the gate electrode, a semiconductor layer provided on the gate insulating film, and a source electrode and a drain electrode which are provided on the semiconductor layer so as to be spaced from each other. 
     A gate electrode GL is provided on the TFT substrate  10  to extend in the X direction. The gate electrode GL functions as a scan line GL. A plurality of pixels of one row arranged in the X direction are connected in common to one scan line GL. A gate insulating film  14  is provided on the TFT substrate  10  and the gate electrode GL. 
     On the gate insulating film  14 , a semiconductor layer  15  is provided for each pixel. For example, amorphous silicon is used as the semiconductor layer  15 . 
     On the semiconductor layer  15  and the gate insulating film  14 , a source electrode  16  and a drain electrode  17  are provided so as to be spaced from each other in a Y direction (which is orthogonal to the X direction). The source electrode  16  and drain electrode  17  each overlap the semiconductor layer  15 . In order to improve electrical connection between the source electrode  16  and the semiconductor layer  15 , an n + -type semiconductor layer into which high-concentration n-type impurities are doped may be provided between them. Similarly, an n + -type semiconductor layer may be provided between the drain electrode  17  and the semiconductor layer  15 . 
     A connection electrode  18  is provided on the gate insulating film  14  to extend in the Y direction. The connection electrode  18  is electrically connected to the drain electrode  17 . 
     Signal lines SL are provided on the gate insulating film  14  to extend in the Y direction. The signal lines SL are each placed at a boundary between adjacent two pixels in the X direction. A plurality of pixels for one row arranged in the Y direction are connected in common to one signal line SL. The signal line SL is electrically connected to the source electrode  16 . 
     An insulating film  19  is provided on the source electrode  16 , drain electrode  17 , connection electrode  18 , signal lines SL and gate insulating film  14 . 
     Reflecting films  20 - 1  and  20 - 2  are provided on the insulating film  19 . The reflecting film  20 - 1  extends in the X direction to cover the TFT  13 . The reflecting film  20 - 2  extends in the X direction to cover a TFT of a pixel adjacent to the pixel in the Y direction. The reflecting films  20 - 1  and  20 - 2  have a function of reflecting external light that is incident from the display surface side. 
     An insulating film  21  is provided on the insulating film  19  and the reflecting films  20 - 1  and  20 - 2 . 
     Pixel electrodes  22 - 1  and  22 - 2  are provided on the insulating film  21 . The pixel electrodes  22 - 1  and  22 - 2  are separated by a slit ST and arranged side by side in the Y direction. In planar view, the pixel electrode  22 - 1  overlaps the reflecting film  20 - 1 . In planar view, the pixel electrode  22 - 2  overlaps the reflecting film  20 - 2 . The planar view is viewing a pixel from above (from the substrate  11  side). 
     The pixel electrode  22 - 1  is electrically connected to the connection electrode  18  by a contact  23 - 1 . The pixel electrode  22 - 2  is electrically connected to the connection electrode  18  by a contact  23 - 2 . 
     A pixel area PA is defined by the pixel electrodes  22 - 1  and  22 - 2  and corresponds to an area of the combination of the pixel electrodes  22 - 1  and  22 - 2 . An area where the pixel electrode  22 - 1  and the reflecting film  20 - 1  overlap, is a reflection area RA 1 . An area where the pixel electrode  22 - 2  and the reflecting film  20 - 2  overlap, is a reflection area RA 2 . In the pixel area PA, an area of the combination of the reflection area RA 1  and RA 2 , is a reflection area of the entire pixel. In the pixel area PA, an area where neither of the reflecting films  20 - 1  and  20 - 2  is provided, is a transmission area TA. The cell gap of the transmission area TA is defined as “d.” The cell gap is the thickness of the liquid crystal layer and is defined by the distance between the pixel electrode and the common electrode. 
     Although not shown, an alignment film is provided on the pixel electrodes  22 - 1  and  22 - 2  and the insulating film  21  to control the alignment of the liquid crystal layer  12 . The alignment film vertically aligns the liquid crystal molecules in the initial state of the liquid crystal layer  12 . 
     Next is a description of the configuration alongside the CF substrate  11 . A color filter  24  is provided on the liquid crystal layer  12  side of the CF substrate  11 . The color filter  24  is any one of a red filter, a green filter and a blue filter. 
     Thickness adjusting layers  25 - 1  and  25 - 2  are provided on the color filter  24 . The thickness adjusting layer  25 - 1  has approximately the same size (area) as the reflecting film  20 - 1 , and is placed so as to overlap the reflecting film  20 - 1  in planar view. The thickness adjusting layer  25 - 2  has approximately the same size (area) as the reflecting film  20 - 2 , and is placed so as to overlap the reflecting film  20 - 2  in planar view. The height (thickness) of each of the thickness adjusting layers  25 - 1  and  25 - 2  is defined as “t.” 
     A common electrode  26  is provided on the color filter  24  and the thickness adjusting layers  25 - 1  and  25 - 2 . The common electrode  26  is provided in common to a plurality of pixels. 
     Protrusions  27 - 1  and  27 - 2  are provided on the common electrode  26 . The protrusion  27 - 1  is disposed so as to overlap the contact  23 - 1  in planar view. The protrusion  27 - 2  is disposed so as to overlap the contact  23 - 2  in planar view. The projections  27 - 1  and  27 - 2  have a function of controlling the alignment of the liquid crystal layer  12 . The protrusions  27 - 1  and  27 - 2  are provided to correspond to the pixel electrodes  22 - 1  and  22 - 2 , respectively. 
     The protrusion  27 - 1  is disposed closer to the center of the pixel than the thickness adjusting layer  25 - 1 . The protrusion  27 - 2  is disposed closer to the center of the pixel than the thickness adjusting layer  25 - 2 . The distance between the protrusion  27 - 1  and the thickness adjusting layer  25 - 1  and the distance between the protrusion  27 - 2  and the thickness adjusting layer  25 - 2  are defined as “L.” 
     In the present embodiment, a multi-domain (alignment division) system, namely, a multi-domain vertical alignment (MVA) mode is applied to the liquid crystal display panel  2 . In the MVA mode, one pixel is divided into a plurality of areas (domains), and the direction in which liquid crystal molecules are inclined in each of the areas is changed. The protrusions  27 - 1  and  27 - 2  control the direction in which the liquid crystal molecules are inclined. That is, the liquid crystal molecules are inclined radially about each of the protrusions  27 - 1  and  27 - 2 . The use of the MVA mode makes it possible to decrease the viewing angle dependence greatly and increase the viewing angle. 
     Instead of the protrusions  27 - 1  and  27 - 2 , openings formed in the common electrode  26  may be used. In this case, the openings have substantially the same size as the protrusions  27 - 1  and  27 - 2 . 
     Although not shown, an alignment film is provided on the common electrode  26  and the protrusions  27 - 1  and  27 - 2  to control the alignment of the liquid crystal layer  12 . The alignment film vertically aligns the liquid crystal molecules in the initial state of the liquid crystal layer  12 . 
     A polarizing plate  28  is stacked on the TFT substrate  10  opposite to the liquid crystal layer  12 , and a polarizing plate  29  is stacked on the CF substrate  11  opposite to the liquid crystal layer  12 . The polarizing plates  28  and  29  are placed such that their transmission axes are orthogonal to each other, that is, in a crossed nicols state. A ¼ wavelength plate may be provided between the TFT substrate  10  and the polarizing plate  28 . A ¼ wavelength plate may be provided between the CF substrate  11  and the polarizing plate  29 . 
     Examples of Materials 
     As the gate electrode GL, source electrode  16 , drain electrode  17  and signal lines SL, for example, any one of aluminum (Al), molybdenum (Mo), chromium (Cr) and tungsten (W), or an alloy containing one or more of these is used. The connection electrode  18 , pixel electrodes  22 - 1  and  22 - 2 , contacts  23 - 1  and  23 - 2 , and the common electrode  26  are formed of a transparent electrode, and, for example, indium tin oxide (ITO) is used. As the reflecting films  20 - 1  and  20 - 2 , for example, aluminum (Al) is used. The gate insulating film  14  and the insulating films  19  and  21  are formed of a transparent insulating material, such as silicon nitride (SiN). The thickness adjusting layers  25 - 1  and  25 - 2  are made of a transparent resin. The protrusions  27 - 1  and  27 - 2  are made of a transparent resin. 
     [1-3] Conditions of Liquid Crystal Display Panel  2   
     Next is a description of the conditions of the liquid crystal display panel  2 .  FIG. 4  is a schematic diagram illustrating the conditions of the liquid crystal display panel  2 . 
     In  FIG. 4 , in the pixel, an area in which the pixel electrode  22 - 1  is provided is a partial pixel area PA 1  and an area in which the pixel electrode  22 - 2  is provided is a partial pixel area PA 2 . The area corresponding to the combination of the partial pixel areas PA 1  and PA 2  is a pixel area PA. The boundary between the partial pixel areas PA 1  and PA 2  corresponds to the center line C of the pixel. 
     In the partial pixel area PA 1 , an area in which the reflecting film  20 - 1  (and the thickness adjusting layer  25 - 1 ) is provided is a reflecting area RA 1  and an area in which the reflecting film  20 - 1  is not provided is a transmitting area TA 1 . In the partial pixel area PA 2 , an area in which the reflecting film  20 - 2  (and the thickness adjusting layer  25 - 2 ) is provided is a reflecting area RA 2  and an area in which the reflecting film  20 - 2  is not provided is a transmitting area TA 2 . An area corresponding to the combination of the reflecting areas RA 1  and RA 2  is a reflecting area RA of the entire pixel. An area corresponding to the combination of the transmitting areas TA 1  and TA 2  is a transmitting area TA of the entire pixel. 
     In planar view, the protrusion  27 - 1  is displaced from the center of the partial pixel area PA 1  in the Y direction toward the reflecting area RA 1 . In planar view, the protrusion  27 - 2  is displaced from the center of the partial pixel area PA 2  in the Y direction toward the reflecting area RA 2 . 
     The following are specific definitions. The distance between the protrusion  27 - 1  and the end of the partial pixel area PA 1  closer to the reflecting area RA 1  is defined as a 1 . The distance between the protrusion  27 - 1  and the other end of the partial pixel area PA 1  (the end closer to the center line of the pixel) is defined as a 2 . The distances a 1  and a 2  have the relation of “a 1 &lt;a 2 .” 
     The distance between the protrusion  27 - 2  and the end of the partial pixel area PA 2  closer to the reflecting area RA 2  is defined as a 3 . The distance between the protrusion  27 - 2  and the other end of the partial pixel area PA 2  (the end closer to the center line of the pixel) is defined as a 4 . The distances a 3  and a 4  have the relation of “a 3 &lt;a 4 .” Preferably, the distances a 3  and a 4  have the relation of “a 1 ≈a 3 ” and “a 2 ≈a 4 ” in order to equalize the upper and lower viewing angle dependence in the Y direction. 
       FIG. 5  is a graph showing the relationship between distance L between a thickness adjusting layer and a protrusion and surface pressure recovery time. The surface pressure means a case where a user applies pressure onto the display surface of the liquid crystal display panel  2  with his or her finger or a pen, and the surface pressure recovery time means time until a display failure, which is caused by the misalignment of a liquid crystal layer due to the surface pressure, is recovered. In  FIG. 5 , the horizontal axis represents the distance L (μm) between the thickness adjusting layer and the protrusion and the vertical axis represents the surface pressure recovery time (sec). The cell gap d of the transmitting area is 3.8 the surface pressure is 0.5 MPa, and the surface pressure hold time is 5 sec. The graph of  FIG. 5  shows (1) a flat gap, (2) a multigap and a reflecting area cell gap of 2.5 μm, and (3) a multigap and a reflecting area cell gap of 2.2 μm. The flat gap means that there is no thickness adjusting layer and thus the gap of the liquid crystal layer is uniform. 
       FIG. 6  is a modification to the graph of multigap shown in  FIG. 5 . In  FIG. 6 , the horizontal axis represents parameter L×D (μm) and the vertical axis represents surface pressure recovery time (sec). The ratio of height  t  of the thickness adjusting layer to cell gap  d  of the transmitting area is defined as D. That is, “D=t/d.” The parameter L×D is the product of the distance L between the thickness adjusting layer and the protrusion and the ratio D. By modifying the graph of  FIG. 5  using the parameters L×D, the surface pressure recovery time can be defined uniquely in a plurality of multigaps. The curve in  FIG. 6  is obtained by fitting using a function of “ax/(b−x).” 
     In the present embodiment, the liquid crystal display panel  2  is capable of recovering a display failure due to surface pressure within 30 seconds. In this case, the distance L between the thickness adjusting layer and the protrusion, the cell gap d of the transmitting area, and the height t of the thickness adjusting layer are set so as to satisfy the condition of “L×D≤4.9 μm.” 
     In the present embodiment, the area of the transmitting area is set larger than that of the reflecting area. For example, the area of the reflecting area is 30% or less of that of the partial pixel area. In other words, the area of the reflecting film  20 - 1  (or the thickness adjusting layer  25 - 1 ) is 30% or less of the area of the pixel electrode  22 - 1 . Referring to  FIG. 2 , the area of the reflecting film  20 - 1  is the area of the portion of the reflecting film  20 - 1  that overlaps the pixel electrode  22 - 1 . Similarly, the area of the reflecting film  20 - 2  (or the thickness adjusting layer  25 - 2 ) is 30% or less of the area of the pixel electrode  22 - 2 . Referring to  FIG. 2 , the area of the reflecting film  20 - 2  is the area of the portion of the reflecting film  20 - 2  that overlaps the pixel electrode  22 - 2 . 
     [1-4] Modification 
     Next is a description of a modification.  FIG. 7  is a schematic diagram of a liquid crystal display panel  2  according to the modification. 
     The configuration of a partial pixel area PA 1  is the same as that in the above-described embodiment. That is, the partial pixel area PA 1  includes a reflecting area RA 1  and a transmitting area TA 1 . The partial pixel area PA 1  is provided with a pixel electrode  22 - 1 , and the reflecting area RA 1  is provided with a reflecting film  20 - 1 . 
     The partial pixel area PA 2  is configured by the transmitting area TA 1  in its entity. The partial pixel area PA 2  is provided with a pixel electrode  22 - 2 . The partial pixel area PA 2  is provided with no reflecting area. A protrusion  27 - 2  is formed in the center of the partial pixel area PA 2 . 
     The conditions of distances a 1  and a 2  in the partial pixel area PA 1  are the same as those in the embodiment. 
     The present embodiment can also be applied to the liquid crystal display panel  2  according to the modification in which a pixel includes one reflecting area. 
     [1-5] Advantageous Effects of First Embodiment 
     In the first embodiment, one pixel is divided into two partial pixel areas PA 1  and PA 2 . The partial pixel area PA 1  includes a reflecting area RA 1  provided with a reflecting film  20 - 1  and a thickness adjusting layer  25 - 1 , and a transmitting area TA 1  other than the reflecting area RA 1 . The partial pixel area PA 2  includes a reflecting area RA 2  provided with a reflecting film  20 - 2  and a thickness adjusting layer  25 - 2 , and a transmitting area TA 2  other than the reflecting area RA 2 . The boundary between the reflecting area RA 1  and the transmitting area TA 1  is stepped by the thickness adjusting layer  25 - 1 . The boundary between the reflecting area RA 2  and the transmitting area TA 2  is stepped by the thickness adjusting layer  25 - 2 . The protrusion  27 - 1  for alignment control is located to shift from the center of the partial pixel area PA 1  (pixel electrode  22 - 1 ) in the Y direction toward the thickness adjusting layer  25 - 1 . Similarly, the protrusion  27 - 2  is located to shift from the center of the partial pixel area PA 2  (pixel electrode  22 - 2 ) in the Y direction toward the thickness adjusting layer  25 - 2 . 
     Therefore, the first embodiment makes it possible to inhibit display quality from being lowered by alignment failure and to inhibit traces, which are caused by the alignment failure at the time of surface pressure, from being left, without decreasing brightness in transmission display. 
     When the area of the reflection area is small, the above advantageous effects can be obtained more effectively if the area of the reflection area is, for example, 30% or less of the area of the partial pixel area. 
     [2] SECOND EMBODIMENT 
     The second embodiment is directed to an example of a configuration example of a three-division pixel in which one pixel is divided into three partial pixels.  FIG. 8  is a plan view of a liquid crystal display panel  2  according to the second embodiment.  FIG. 9  is a sectional view of the liquid crystal display panel  2  taken along line A-A′ in  FIG. 8 . 
     Pixel electrodes  22 - 1 ,  22 - 2  and  22 - 3  are provided on an insulating film  21 . The pixel electrodes  22 - 1 ,  22 - 2  and  22 - 3  are separated by slits ST. The pixel electrode  22 - 1 , pixel electrode  22 - 3  and pixel electrode  22 - 2  are arranged in the Y direction in the order presented here. 
     The pixel electrode  22 - 3  is electrically connected to a connection electrode  18  by a contact  23 - 3 . 
     In planar view, a reflection film  20 - 1  overlaps the pixel electrode  22 - 1 . In planar view, a reflection film  20 - 2  overlaps the pixel electrode  22 - 2 . No reflection film is provided below the pixel electrode  22 - 3 . 
     A protrusion  27 - 3  is provided on a common electrode  26 . In planar view, the protrusion  27 - 3  is placed at the center of the pixel electrode  22 - 3  in the Y direction. 
     As in the first embodiment, a thickness adjusting layer  25 - 1  is provided on a color filter  24  and above the reflection film  20 - 1 . A protrusion  27 - 1  is provided on the common electrode  26  and above the pixel electrode  22 - 1 . A thickness adjusting layer  25 - 2  is provided on the color filter  24  and above the reflection film  20 - 2 . A protrusion  27 - 2  is provided on the common electrode  26  and above the pixel electrode  22 - 2 . 
       FIG. 10  is a schematic diagram of the liquid crystal display panel  2  according to the second embodiment. 
     In each pixel, an area where the pixel electrode  22 - 1  is provided is a partial pixel area PA 1 , an area where the pixel electrode  22 - 2  is provided is a partial pixel area PA 2 , and an area where the pixel electrode  22 - 3  is provided is a partial pixel area PA 3 . The partial pixel area PA 3  as a whole is configured by a transmission area TA 3 . The protrusion  27 - 3  is placed on the centerline C of the pixel. 
     The conditions of distances a 1  to a 4  shown in  FIG. 10  are the same as those in the first embodiment. The second embodiment also makes it possible to inhibit display quality from being lowered without decreasing brightness in transmission display. 
     The present invention is not limited to the foregoing embodiments. When the invention is reduced to practice, a variety of modifications can be made without departing from the spirit of the invention. The embodiments can be combined as appropriate, and advantageous effects can be obtained from the combination. Furthermore, the foregoing embodiments include a variety of inventions, and a variety of inventions can be extracted by selecting and combining a plurality of structural elements. For example, even though some of the structural elements are deleted from the embodiments, a configuration from which the structural elements are deleted can be extracted as an invention if the problem can be solved and an advantageous effect can be obtained.