Patent Description:
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 (refer to patent literatures <NUM> and <NUM>, 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 <NUM>).

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 <NUM>), controlling the height (patent literature <NUM>) and inclination (patent literature <NUM>) 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 <NUM>), forming a recess in the reflection area and placing the protrusion in the recess (patent literature <NUM>), and the like.

Document <CIT> discloses a liquid crystal display and a pixel structure. The pixel structure has a pair of substrates, a liquid crystal layer, pixel regions, a patterned organic material layer, and a shielding layer. The liquid crystal layer is disposed between the pair of substrates. The pixel regions are provided on the substrates, and each of the pixel regions is defined by at least two common lines and at least one data line and includes at least two sub-pixel regions. Each pixel region has a pixel electrode which has a main slit adjacent to the border between the two sub-pixel regions. The patterned organic material layer is disposed on one of the substrates and corresponds to one of the sub-pixel regions. The shielding layer is placed corresponding to the main slit.

Document <CIT> discloses a liquid crystal device which uses liquid crystal having negative dielectric constant anisotropy.

Document <CIT> discloses a transflective liquid crystal display device that prevents display failure, such as an afterimage and unevenness like stains, and achieves a bright display with a wide viewing angle in both transmissive display and reflective display.

Document <CIT> discloses a liquid crystal display panel (LCD panel) and to a pixel structure in an LCD panel.

Document <CIT> discloses a liquid crystal display device in which a liquid crystal layer is interposed between a pair of substrates, and display is performed in predetermined dot regions. A plurality of sub-dot regions is provided in each dot region, the plurality of sub-dot regions being electrically connected to each other through their connecting portions. Each sub-dot region is provided with an alignment regulating device to regulate the alignment direction of the vertically aligned liquid crystal molecules, such that the liquid crystal molecules are inclined substantially in a radial direction around the alignment regulating device. Each alignment regulating device is arranged so as to deviate from the center of the sub-dot region.

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 <NUM>% 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.

The present invention provides a liquid crystal display device capable of inhibiting display quality from lowering without lowering the brightness of transmission display.

According to an aspect of the present invention, there is provided a liquid crystal display device comprising:.

Further aspects and features of the present invention are set out in the dependent claims.

According to the present invention, a liquid crystal display device capable of inhibiting display quality from lowering without lowering the brightness of transmission display, can be provided.

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.

<FIG> is a block diagram of a liquid crystal display device <NUM> according to a first embodiment of the present invention. The liquid crystal display device <NUM> includes a liquid crystal display panel <NUM>, a backlight (illumination device) <NUM>, a scan line driving circuit <NUM>, a signal line driving circuit <NUM>, a common electrode driver <NUM>, a voltage generation circuit <NUM> and a control circuit <NUM>.

The liquid crystal display panel <NUM> includes a pixel array in which a plurality of pixels PX are arranged in a matrix. The liquid crystal display panel <NUM> includes a plurality of scan lines GL1 to GLm each extending in the row direction and a plurality of signal lines SL1 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 <NUM> is a surface light source that irradiates the back surface of the liquid crystal display panel <NUM> with light. As the backlight <NUM>, for example, a direct type or a side light (edge light) type LED backlight is used.

The scan line driving circuit <NUM> is electrically connected to the scan lines GL. Upon receiving a control signal from the control circuit <NUM>, the scan line driving circuit <NUM> sends scan signals to the liquid crystal display panel <NUM> to turn on/off the switching elements included in the pixels PX.

The signal line driving circuit <NUM> is electrically connected to the signal lines SL. The signal line driving circuit <NUM> receives a control signal and display data from the control circuit <NUM>. In response to the control signal, the signal line driving circuit <NUM> sends gradation signals (drive voltages) corresponding to the display data to the liquid crystal display panel <NUM>.

The common electrode driver <NUM> generates a common voltage Vcom and applies it to the common electrode in the liquid crystal display panel <NUM>. The voltage generation circuit <NUM> generates various voltages necessary for the operation of the liquid crystal display device <NUM> and applies them to the respective circuits.

The control circuit <NUM> collectively controls the operation of the liquid crystal display device <NUM>. The control circuit <NUM> externally receives image data DT and control signal CNT. Based on the image data DT, the control circuit <NUM> generates various control signals and sends the control signals to each of the circuits.

The liquid crystal display panel <NUM> according to the present embodiment is a transflective liquid crystal display panel capable of transmission display and reflection display.

<FIG> is a plan view of the liquid crystal display panel <NUM> according to the first embodiment. <FIG> is a sectional view of the liquid crystal display panel <NUM> taken along line A-A' in <FIG>. In <FIG>, a portion corresponding to one pixel is extracted and actually, a plurality of pixels each corresponding to the pixel shown in <FIG> are arranged in a matrix.

The liquid crystal display panel <NUM> includes a TFT substrate <NUM> on which a switching element (TFT), a pixel electrode and the like are formed, and a color filter substrate (CF substrate) <NUM> on which a color filter, a common electrode and the like are formed and which is opposed to the TFT substrate <NUM>. Each of the TFT and CF substrates <NUM> and <NUM> is configured by a transparent substrate (for example, a glass substrate or a plastic substrate).

The liquid crystal layer <NUM> is filled between the TFT and CF substrates <NUM> and <NUM>. Specifically, the liquid crystal layer <NUM> is sealed in a display area surrounded by the TFT and CF substrates <NUM> and <NUM> 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 <NUM> or the CF substrate <NUM> in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like.

The liquid crystal materials of the liquid crystal layer <NUM> 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 <NUM> and <NUM>. The liquid crystal display panel <NUM> 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 <NUM>. The liquid crystal layer <NUM> is vertically aligned in an initial state. When no voltage (no electric field) is applied to the liquid crystal layer <NUM>, 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 <NUM>, 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 <NUM>. A switching element <NUM> is provided for each pixel on the liquid crystal layer <NUM> side of the TFT substrate <NUM>. As the switching element <NUM>, for example, a thin film transistor (TFT) and an n-channel TFT are used. As will be described later, the TFT <NUM> 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 <NUM> 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 <NUM> is provided on the TFT substrate <NUM> and the gate electrode GL.

On the gate insulating film <NUM>, a semiconductor layer <NUM> is provided for each pixel. For example, amorphous silicon is used as the semiconductor layer <NUM>.

On the semiconductor layer <NUM> and the gate insulating film <NUM>, a source electrode <NUM> and a drain electrode <NUM> are provided so as to be spaced from each other in a Y direction (which is orthogonal to the X direction). The source electrode <NUM> and drain electrode <NUM> each overlap the semiconductor layer <NUM>. In order to improve electrical connection between the source electrode <NUM> and the semiconductor layer <NUM>, 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 <NUM> and the semiconductor layer <NUM>.

A connection electrode <NUM> is provided on the gate insulating film <NUM> to extend in the Y direction. The connection electrode <NUM> is electrically connected to the drain electrode <NUM>.

Signal lines SL are provided on the gate insulating film <NUM> 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 <NUM>.

An insulating film <NUM> is provided on the source electrode <NUM>, drain electrode <NUM>, connection electrode <NUM>, signal lines SL and gate insulating film <NUM>.

Reflecting films <NUM>-<NUM> and <NUM>-<NUM> are provided on the insulating film <NUM>. The reflecting film <NUM>-<NUM> extends in the X direction to cover the TFT <NUM>. The reflecting film <NUM>-<NUM> extends in the X direction to cover a TFT of a pixel adjacent to the pixel in the Y direction. The reflecting films <NUM>-<NUM> and <NUM>-<NUM> have a function of reflecting external light that is incident from the display surface side.

An insulating film <NUM> is provided on the insulating film <NUM> and the reflecting films <NUM>-<NUM> and <NUM>-<NUM>.

Pixel electrodes <NUM>-<NUM> and <NUM>-<NUM> are provided on the insulating film <NUM>. The pixel electrodes <NUM>-<NUM> and <NUM>-<NUM> are separated by a slit ST and arranged side by side in the Y direction. In planar view, the pixel electrode <NUM>-<NUM> overlaps the reflecting film <NUM>-<NUM>. In planar view, the pixel electrode <NUM>-<NUM> overlaps the reflecting film <NUM>-<NUM>. The planar view is viewing a pixel from above (from the substrate <NUM> side).

The pixel electrode <NUM>-<NUM> is electrically connected to the connection electrode <NUM> by a contact <NUM>-<NUM>. The pixel electrode <NUM>-<NUM> is electrically connected to the connection electrode <NUM> by a contact <NUM>-<NUM>.

A pixel area PA is defined by the pixel electrodes <NUM>-<NUM> and <NUM>-<NUM> and corresponds to an area of the combination of the pixel electrodes <NUM>-<NUM> and <NUM>-<NUM>. An area where the pixel electrode <NUM>-<NUM> and the reflecting film <NUM>-<NUM> overlap, is a reflection area RA1. An area where the pixel electrode <NUM>-<NUM> and the reflecting film <NUM>-<NUM> overlap, is a reflection area RA2. In the pixel area PA, an area of the combination of the reflection area RA1 and RA2, is a reflection area of the entire pixel. In the pixel area PA, an area where neither of the reflecting films <NUM>-<NUM> and <NUM>-<NUM> 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 <NUM>-<NUM> and <NUM>-<NUM> and the insulating film <NUM> to control the alignment of the liquid crystal layer <NUM>. The alignment film vertically aligns the liquid crystal molecules in the initial state of the liquid crystal layer <NUM>.

Next is a description of the configuration alongside the CF substrate <NUM>. A color filter <NUM> is provided on the liquid crystal layer <NUM> side of the CF substrate <NUM>. The color filter <NUM> is any one of a red filter, a green filter and a blue filter.

Thickness adjusting layers <NUM>-<NUM> and <NUM>-<NUM> are provided on the color filter <NUM>. The thickness adjusting layer <NUM>-<NUM> has approximately the same size (area) as the reflecting film <NUM>-<NUM>, and is placed so as to overlap the reflecting film <NUM>-<NUM> in planar view. The thickness adjusting layer <NUM>-<NUM> has approximately the same size (area) as the reflecting film <NUM>-<NUM>, and is placed so as to overlap the reflecting film <NUM>-<NUM> in planar view. The height (thickness) of each of the thickness adjusting layers <NUM>-<NUM> and <NUM>-<NUM> is defined as "t.

A common electrode <NUM> is provided on the color filter <NUM> and the thickness adjusting layers <NUM>-<NUM> and <NUM>-<NUM>. The common electrode <NUM> is provided in common to a plurality of pixels.

Protrusions <NUM>-<NUM> and <NUM>-<NUM> are provided on the common electrode <NUM>. The protrusion <NUM>-<NUM> is disposed so as to overlap the contact <NUM>-<NUM> in planar view. The protrusion <NUM>-<NUM> is disposed so as to overlap the contact <NUM>-<NUM> in planar view. The projections <NUM>-<NUM> and <NUM>-<NUM> have a function of controlling the alignment of the liquid crystal layer <NUM>. The protrusions <NUM>-<NUM> and <NUM>-<NUM> are provided to correspond to the pixel electrodes <NUM>-<NUM> and <NUM>-<NUM>, respectively.

The protrusion <NUM>-<NUM> is disposed closer to the center of the pixel than the thickness adjusting layer <NUM>-<NUM>. The protrusion <NUM>-<NUM> is disposed closer to the center of the pixel than the thickness adjusting layer <NUM>-<NUM>. The distance between the protrusion <NUM>-<NUM> and the thickness adjusting layer <NUM>-<NUM> and the distance between the protrusion <NUM>-<NUM> and the thickness adjusting layer <NUM>-<NUM> 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 <NUM>. 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 <NUM>-<NUM> and <NUM>-<NUM> 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 <NUM>-<NUM> and <NUM>-<NUM>. The use of the MVA mode makes it possible to decrease the viewing angle dependence greatly and increase the viewing angle.

In an alternative embodiment which is not covered by the features of the appended claims, but which is useful for understanding the claimed invention, instead of the protrusions <NUM>-<NUM> and <NUM>-<NUM>, openings formed in the common electrode <NUM> may be used. In this case, the openings have substantially the same size as the protrusions <NUM>-<NUM> and <NUM>-<NUM>.

Although not shown, an alignment film is provided on the common electrode <NUM> and the protrusions <NUM>-<NUM> and <NUM>-<NUM> to control the alignment of the liquid crystal layer <NUM>. The alignment film vertically aligns the liquid crystal molecules in the initial state of the liquid crystal layer <NUM>.

A polarizing plate <NUM> is stacked on the TFT substrate <NUM> opposite to the liquid crystal layer <NUM>, and a polarizing plate <NUM> is stacked on the CF substrate <NUM> opposite to the liquid crystal layer <NUM>. The polarizing plates <NUM> and <NUM> are placed such that their transmission axes are orthogonal to each other, that is, in a crossed nicols state. A <NUM>/<NUM> wavelength plate may be provided between the TFT substrate <NUM> and the polarizing plate <NUM>. A <NUM>/<NUM> wavelength plate may be provided between the CF substrate <NUM> and the polarizing plate <NUM>.

As the gate electrode GL, source electrode <NUM>, drain electrode <NUM> 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 <NUM>, pixel electrodes <NUM>-<NUM> and <NUM>-<NUM>, contacts <NUM>-<NUM> and <NUM>-<NUM>, and the common electrode <NUM> are formed of a transparent electrode, and, for example, indium tin oxide (ITO) is used. As the reflecting films <NUM>-<NUM> and <NUM>-<NUM>, for example, aluminum (Al) is used. The gate insulating film <NUM> and the insulating films <NUM> and <NUM> are formed of a transparent insulating material, such as silicon nitride (SiN). The thickness adjusting layers <NUM>-<NUM> and <NUM>-<NUM> are made of a transparent resin. The protrusions <NUM>-<NUM> and <NUM>-<NUM> are made of a transparent resin.

Next is a description of the conditions of the liquid crystal display panel <NUM>. <FIG> is a schematic diagram illustrating the conditions of the liquid crystal display panel <NUM>.

In <FIG>, in the pixel, an area in which the pixel electrode <NUM>-<NUM> is provided is a partial pixel area PA1 and an area in which the pixel electrode <NUM>-<NUM> is provided is a partial pixel area PA2. The area corresponding to the combination of the partial pixel areas PA1 and PA2 is a pixel area PA. The boundary between the partial pixel areas PA1 and PA2 corresponds to the center line C of the pixel.

In the partial pixel area PA1, an area in which the reflecting film <NUM>-<NUM> (and the thickness adjusting layer <NUM>-<NUM>) is provided is a reflecting area RA1 and an area in which the reflecting film <NUM>-<NUM> is not provided is a transmitting area TA1. In the partial pixel area PA2, an area in which the reflecting film <NUM>-<NUM> (and the thickness adjusting layer <NUM>-<NUM>) is provided is a reflecting area RA2 and an area in which the reflecting film <NUM>-<NUM> is not provided is a transmitting area TA2. An area corresponding to the combination of the reflecting areas RA1 and RA2 is a reflecting area RA of the entire pixel. An area corresponding to the combination of the transmitting areas TA1 and TA2 is a transmitting area TA of the entire pixel.

In planar view, the protrusion <NUM>-<NUM> is displaced from the center of the partial pixel area PA1 in the Y direction toward the reflecting area RA1. In planar view, the protrusion <NUM>-<NUM> is displaced from the center of the partial pixel area PA2 in the Y direction toward the reflecting area RA2.

The following are specific definitions. The distance between the protrusion <NUM>-<NUM> and the end of the partial pixel area PA1 closer to the reflecting area RA1 is defined as a1. The distance between the protrusion <NUM>-<NUM> and the other end of the partial pixel area PA1 (the end closer to the center line of the pixel) is defined as a2. The distances a1 and a2 have the relation of "a1 < a2.

The distance between the protrusion <NUM>-<NUM> and the end of the partial pixel area PA2 closer to the reflecting area RA2 is defined as a3. The distance between the protrusion <NUM>-<NUM> and the other end of the partial pixel area PA2 (the end closer to the center line of the pixel) is defined as a4. The distances a3 and a4 have the relation of "a3 < a4. " Preferably, the distances a3 and a4 have the relation of "a1 ≒ a3" and "a2 ≒ a4" in order to equalize the upper and lower viewing angle dependence in the Y direction.

<FIG> 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 <NUM> 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>, the horizontal axis represents the distance L (um) 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 <NUM>, the surface pressure is <NUM> MPa, and the surface pressure hold time is <NUM> sec. The graph of <FIG> shows (<NUM>) a flat gap, (<NUM>) a multigap and a reflecting area cell gap of <NUM>, and (<NUM>) a multigap and a reflecting area cell gap of <NUM>. The flat gap means that there is no thickness adjusting layer and thus the gap of the liquid crystal layer is uniform.

<FIG> is a modification to the graph of multigap shown in <FIG>. In <FIG>, the horizontal axis represents parameter L × D (pm) 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> using the parameters L × D, the surface pressure recovery time can be defined uniquely in a plurality of multigaps. The curve in <FIG> is obtained by fitting using a function of "ax/(b-x).

In the present embodiment, the liquid crystal display panel <NUM> is capable of recovering a display failure due to surface pressure within <NUM> 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 ≦ <NUM>.

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 <NUM>% or less of that of the partial pixel area. In other words, the area of the reflecting film <NUM>-<NUM> (or the thickness adjusting layer <NUM>-<NUM>) is <NUM>% or less of the area of the pixel electrode <NUM>-<NUM>. Referring to <FIG>, the area of the reflecting film <NUM>-<NUM> is the area of the portion of the reflecting film <NUM>-<NUM> that overlaps the pixel electrode <NUM>-<NUM>. Similarly, the area of the reflecting film <NUM>-<NUM> (or the thickness adjusting layer <NUM>-<NUM>) is <NUM>% or less of the area of the pixel electrode <NUM>-<NUM>. Referring to <FIG>, the area of the reflecting film <NUM>-<NUM> is the area of the portion of the reflecting film <NUM>-<NUM> that overlaps the pixel electrode <NUM>-<NUM>.

Next is a description of a modification. <FIG> is a schematic diagram of a liquid crystal display panel <NUM> according to the modification.

The configuration of a partial pixel area PA1 is the same as that in the above-described embodiment. That is, the partial pixel area PA1 includes a reflecting area RA1 and a transmitting area TA1. The partial pixel area PA1 is provided with a pixel electrode <NUM>-<NUM>, and the reflecting area RA1 is provided with a reflecting film <NUM>-<NUM>.

The partial pixel area PA2 is configured by the transmitting area TA1 in its entity. The partial pixel area PA2 is provided with a pixel electrode <NUM>-<NUM>. The partial pixel area PA2 is provided with no reflecting area. A protrusion <NUM>-<NUM> is formed in the center of the partial pixel area PA2.

The conditions of distances a1 and a2 in the partial pixel area PA1 are the same as those in the embodiment.

The present embodiment can also be applied to the liquid crystal display panel <NUM> according to the modification in which a pixel includes one reflecting area.

In the first embodiment, one pixel is divided into two partial pixel areas PA1 and PA2. The partial pixel area PA1 includes a reflecting area RA1 provided with a reflecting film <NUM>-<NUM> and a thickness adjusting layer <NUM>-<NUM>, and a transmitting area TA1 other than the reflecting area RA1. The partial pixel area PA2 includes a reflecting area RA2 provided with a reflecting film <NUM>-<NUM> and a thickness adjusting layer <NUM>-<NUM>, and a transmitting area TA2 other than the reflecting area RA2. The boundary between the reflecting area RA1 and the transmitting area TA1 is stepped by the thickness adjusting layer <NUM>-<NUM>. The boundary between the reflecting area RA2 and the transmitting area TA2 is stepped by the thickness adjusting layer <NUM>-<NUM>. The protrusion <NUM>-<NUM> for alignment control is located to shift from the center of the partial pixel area PA1 (pixel electrode <NUM>-<NUM>) in the Y direction toward the thickness adjusting layer <NUM>-<NUM>. Similarly, the protrusion <NUM>-<NUM> is located to shift from the center of the partial pixel area PA2 (pixel electrode <NUM>-<NUM>) in the Y direction toward the thickness adjusting layer <NUM>-<NUM>.

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, <NUM>% or less of the area of the partial pixel area.

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> is a plan view of a liquid crystal display panel <NUM> according to the second embodiment. <FIG> is a sectional view of the liquid crystal display panel <NUM> taken along line A-A' in <FIG>.

Pixel electrodes <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> are provided on an insulating film <NUM>. The pixel electrodes <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM> are separated by slits ST. The pixel electrode <NUM>-<NUM>, pixel electrode <NUM>-<NUM> and pixel electrode <NUM>-<NUM> are arranged in the Y direction in the order presented here.

The pixel electrode <NUM>-<NUM> is electrically connected to a connection electrode <NUM> by a contact <NUM>-<NUM>.

In planar view, a reflection film <NUM>-<NUM> overlaps the pixel electrode <NUM>-<NUM>. In planar view, a reflection film <NUM>-<NUM> overlaps the pixel electrode <NUM>-<NUM>. No reflection film is provided below the pixel electrode <NUM>-<NUM>.

A protrusion <NUM>-<NUM> is provided on a common electrode <NUM>. In planar view, the protrusion <NUM>-<NUM> is placed at the center of the pixel electrode <NUM>-<NUM> in the Y direction.

As in the first embodiment, a thickness adjusting layer <NUM>-<NUM> is provided on a color filter <NUM> and above the reflection film <NUM>-<NUM>. A protrusion <NUM>-<NUM> is provided on the common electrode <NUM> and above the pixel electrode <NUM>-<NUM>. A thickness adjusting layer <NUM>-<NUM> is provided on the color filter <NUM> and above the reflection film <NUM>-<NUM>. A protrusion <NUM>-<NUM> is provided on the common electrode <NUM> and above the pixel electrode <NUM>-<NUM>.

<FIG> is a schematic diagram of the liquid crystal display panel <NUM> according to the second embodiment.

In each pixel, an area where the pixel electrode <NUM>-<NUM> is provided is a partial pixel area PA1, an area where the pixel electrode <NUM>-<NUM> is provided is a partial pixel area PA2, and an area where the pixel electrode <NUM>-<NUM> is provided is a partial pixel area PA3. The partial pixel area PA3 as a whole is configured by a transmission area TA3. The protrusion <NUM>-<NUM> is placed on the centerline C of the pixel.

The conditions of distances a1 to a4 shown in <FIG> 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.

Claim 1:
A liquid crystal display device (<NUM>) comprising:
first and second substrates (<NUM>, <NUM>);
a liquid crystal layer (<NUM>) interposed between the first and second substrates (<NUM>, <NUM>) and set in vertical alignment (VA) when no electric field is applied;
a switching element (<NUM>) provided on the first substrate (<NUM>);
a connection electrode (<NUM>) provided on the first substrate (<NUM>), connected to the switching element (<NUM>), and extending in a first direction;
a first reflection film (<NUM>-<NUM>) provided above the switching element (<NUM>) with a first insulating film (<NUM>) therebetween;
a first pixel electrode (<NUM>-<NUM>) provided above the first reflection film (<NUM>-<NUM>) with a second insulating film (<NUM>) therebetween and overlapping the first reflection film (<NUM>-<NUM>) in planar view;
a second pixel electrode (<NUM>-<NUM>) located adjacent to the first pixel electrode (<NUM>-<NUM>) in the first direction;
first and second contacts (<NUM>-<NUM>, <NUM>-<NUM>) which connect the first and second pixel electrodes (<NUM>-<NUM>, <NUM>-<NUM>) to the connection electrode (<NUM>);
a first thickness adjusting layer (<NUM>-<NUM>) provided on the second substrate (<NUM>) and overlapping the first reflection film (<NUM>-<NUM>) in planar view;
a common electrode (<NUM>) provided on the second substrate (<NUM>) and the first thickness adjusting layer (<NUM>-<NUM>); and
first and second protrusions (<NUM>-<NUM>, <NUM>-<NUM>) provided on the common electrode (<NUM>), not overlapping the first thickness adjusting layer (<NUM>-<NUM>) in planar view, and overlapping the first and second pixel electrodes (<NUM>-<NUM>, <NUM>-<NUM>) in planar view, respectively,
characterized in that
the first protrusion (<NUM>-<NUM>) is located at a position shifted toward the first thickness adjusting layer (<NUM>-<NUM>) from a center of the first pixel electrode (<NUM>-<NUM>) in the first direction.