JP4607237B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid crystal display device used in a display unit of information equipment and the like and a manufacturing method thereof, and more particularly to a transflective liquid crystal display device used in low power consumption equipment such as a portable information terminal and a manufacturing method thereof.

  In recent years, an active matrix liquid crystal display device including a thin film transistor (TFT) for each pixel has been widely used as a display device for all purposes. Under such circumstances, a transflective liquid crystal display device capable of display in both reflection and transmission modes is used as a display device for a mobile terminal or a notebook PC. It has become like this.

  Here, a conventional liquid crystal display device will be described. FIG. 31 shows a cross-sectional configuration of the reflective liquid crystal display device described in Non-Patent Document 1. As shown in FIG. 31, a liquid crystal 106 is sealed between a pair of substrates 102 and 104 arranged to face each other. The alignment state of the liquid crystal 106 is a bend alignment called ROCB. A reflective electrode 116 having a mirror-like and flat reflective surface is formed on the surface of one substrate 102 on the liquid crystal 106 side. A common electrode 142 made of a transparent conductive film is formed on the surface of the other substrate 104 on the liquid crystal 106 side. On the panel outer side (observer side) of the other substrate 104, a retardation film (¼ wavelength plate) 120, a polarizing plate 122, and an optical path control film 124 are arranged in this order.

  The incident external light is bent by the optical path control film 124, reaches the reflective electrode 116, is reflected, and is emitted to the viewer side. Since the optical path control film 124 that diffuses and transmits the light is provided, the optical path of the light reflected on the surface of the optical path control film 124 and the optical path of the light that passes through the optical path control film 124 and reflected on the surface of the reflective electrode 116 Is different. For this reason, when an observer looks at a display screen, a display and external light do not overlap, and a clear display image can be observed.

  FIG. 32 shows a configuration of a transflective liquid crystal display device described in Non-Patent Document 2. FIG. 32A shows a configuration of almost one pixel of the transflective liquid crystal display device, and FIG. 32B is a cross-sectional configuration of the transflective liquid crystal display device cut along line XX in FIG. Is shown. As shown in FIGS. 32A and 32B, the pixel region is divided into a transmissive region T and a reflective region R. An insulator (resin layer) 130 is formed in the reflective region R of the TFT substrate 102 so that the cell thickness of the reflective region R is half that of the transmissive region T. On the insulator 130, a reflective electrode 116 having an uneven surface is formed. A projection 132 for regulating the alignment of the vertical alignment type liquid crystal 106 is formed at the center of the transmission region T of the counter substrate 104. A pair of quarter-wave plates 120 are respectively arranged on the panel outside of the TFT substrate 102 and the counter substrate 104. A pair of polarizing plates 122 are arranged on the outer side of each quarter-wave plate 120.

  This liquid crystal display device is the same as the liquid crystal display device shown in FIG. 31 in that the reflective electrode 116 is formed on the surface of the substrate 102 on the liquid crystal 106 side, but the reflective surface of the reflective electrode 116 is uneven. External light incident from the observer side is scattered and reflected by the reflective electrode 116 and is emitted to the observer side.

  FIG. 33A shows a state in which no voltage is applied to the liquid crystal 106, and FIG. 33B shows a state in which a predetermined voltage is applied to the liquid crystal 106. As shown in FIG. 33 (a), in a state where no voltage is applied, the liquid crystal molecules are aligned perpendicular to the substrate surface, so that the liquid crystal 106 does not exhibit an optical effect on light. When performing reflective display, the light transmitted through the polarizing plate 122 is transmitted through the quarter-wave plate 120 and incident on the liquid crystal 106, reflected by the reflective electrode 116, and then transmitted through the quarter-wave plate 120 again. That is, when the light passes through the quarter-wave plate 120 twice, its polarization state is rotated by 90 °. Therefore, this light is absorbed by the polarizing plate 122. For this reason, black is displayed in the reflection mode.

  In addition, when performing transmissive display, the light transmitted through the polarizing plate 122 on the backlight unit 188 side is transmitted through the ¼ wavelength plate 120 and enters the liquid crystal 106, and the ¼ wavelength plate 120 on the viewer side is transmitted. To Penetrate. That is, when the light passes through the quarter-wave plate 120 twice, its polarization state is rotated by 90 °. Therefore, this light is absorbed by the polarizing plate 122 on the viewer side. For this reason, black is displayed in the transmission mode.

  On the other hand, in a state where a predetermined voltage is applied, the liquid crystal molecules tilt with respect to the substrate surface, so that the liquid crystal 106 exhibits a predetermined optical effect on light. As shown in FIG. 33B, the polarization state of the light transmitted through the polarizing plate 122 is changed by the liquid crystal 106. For this reason, white is displayed in both the reflection and transmission modes.

JP 2000-56326 A JP 2000-171789 A JP 2002-202511 A JP-A-6-175126 JP-A-7-311383 JP-A-11-281972

SID96 Digest, p. 618-621 Asia Display / IDW'01, p. 133 (2001)

  In the configuration of the reflective liquid crystal display device as shown in FIG. 31, the combined use with the transmissive type has not been realized so far. This is because in the reflective type, the alignment state of the liquid crystal 106 is a hybrid alignment on the assumption that light passes through the liquid crystal 106 twice. In the hybrid orientation, there is a problem that the birefringence is small for use as a transmission type, and sufficient white display cannot be performed. In addition, the transmission type has a problem that viewing angle characteristics are low.

  On the other hand, in the transflective liquid crystal display device shown in FIGS. 32 and 33, it has been proposed to form the surface of the reflective electrode 116 in an uneven shape. However, in order to manufacture a transflective liquid crystal display device having an uneven reflective electrode 116, in addition to the normal manufacturing process of a transmissive liquid crystal display device, formation and patterning of a resin layer, formation of the reflective electrode 116, etc. This process is further required. For this reason, the problem that the manufacturing cost of a liquid crystal display device will raise arises.

  An object of the present invention is to provide a liquid crystal display device and a method for manufacturing the liquid crystal display device that can obtain good display characteristics without increasing the manufacturing cost.

  The object is to provide a pair of opposed substrates, a liquid crystal sealed between the pair of substrates and aligned substantially perpendicular to the substrate when no voltage is applied, and an outer side of the pair of substrates. A pair of quarter-wave plates, a pair of polarizing plates respectively disposed on the outside of the pair of quarter-wave plates, and a substantially flat reflecting surface, and is incident from one side of the pair of substrates. A pixel region including a reflective region including a reflective plate that reflects light and a transmissive region that transmits light incident from the other side of the pair of substrates to one side of the pair of substrates; This is achieved by a liquid crystal display device.

  As described above, according to the present invention, it is possible to realize a liquid crystal display device capable of obtaining good display characteristics without increasing the manufacturing cost.

It is a figure which shows the basic composition of the liquid crystal display device by the 1st Embodiment of this invention. It is a figure which shows schematic structure of the liquid crystal display device by Example 1-1 of the 1st Embodiment of this invention. It is a figure which shows the structure of the liquid crystal display device by Example 1-1 of the 1st Embodiment of this invention. It is a figure which shows the structure of the conventional liquid crystal display device. It is a figure which shows the modification of a structure of the liquid crystal display device by Example 1-1 of the 1st Embodiment of this invention. It is a figure which shows the structure of the liquid crystal display device by Example 1-2 of the 1st Embodiment of this invention. It is a figure which shows the structure of the conventional liquid crystal display device. It is a figure which shows arrangement | positioning of the polarizing plate etc. of the liquid crystal display device by Example 1-2 of the 1st Embodiment of this invention. It is a block diagram which shows the drive method of the liquid crystal display device by Example 1-3 of the 1st Embodiment of this invention. It is a figure which shows the structure of the liquid crystal display device by Example 1-4 of the 1st Embodiment of this invention. It is a figure which shows the modification of a structure of the liquid crystal display device by Example 1-4 of the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device used as the premise of the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device used as the premise of the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device by the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device by the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device by the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device by the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device by the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device by the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device by the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the liquid crystal display device by the 2nd Embodiment of this invention. It is a figure for demonstrating the liquid crystal display device by the 2nd Embodiment of this invention. It is a figure for demonstrating the liquid crystal display device by the 2nd Embodiment of this invention. It is a figure which shows arrangement | positioning of the reflective protrusion of the liquid crystal display device by Example 2-1 of the 2nd Embodiment of this invention. It is a photograph which shows the structure of the liquid crystal display device by Example 2-1 of the 2nd Embodiment of this invention. It is the orientation photograph at the time of displaying white by reflection mode. It is an orientation photograph when white is displayed in the transmission mode. It is a graph which shows the result of having measured the reflective characteristic of the liquid crystal display device by Example 2-1 of the 2nd Embodiment of this invention. It is a graph which shows the result of having measured the reflective characteristic of the liquid crystal display device by Example 2-1 of the 2nd Embodiment of this invention. It is a graph which shows the result of having measured the transmission characteristic of the liquid crystal display device by Example 2-1 of the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the conventional liquid crystal display device. It is a figure which shows the structure of the conventional liquid crystal display device. It is sectional drawing which shows the structure of the conventional liquid crystal display device.

[First Embodiment]
A liquid crystal display device according to a first embodiment of the present invention and a manufacturing method thereof will be described with reference to FIGS. In this embodiment, the excellent points of the two liquid crystal display devices already described as conventional examples are extracted and combined, and further devised so that it is not necessary to change the manufacturing process of a normal transmission type liquid crystal display device. It is.

  FIG. 1 is a cross-sectional view schematically showing the basic configuration of the liquid crystal display device according to the present embodiment. FIG. 1A shows an optical path for reflective display, and FIG. 1B shows an optical path for transmissive display. As shown in FIGS. 1A and 1B, a liquid crystal 6 is sealed between the TFT substrate 2 and the counter substrate 4 that are arranged to face each other. The alignment state of the liquid crystal 6 is vertical alignment. The TFT substrate 2 has a metal reflector 54 formed on the glass substrate 10 and having a substantially flat reflecting surface. For the reflection plate 54, for example, an electrode such as a storage capacitor electrode is used. An insulating film 30 is formed on the reflection plate 54. A substantially flat and transparent pixel electrode 16 is formed on the insulating film 30. The counter substrate 4 has a transparent common electrode 42 formed on the glass substrate 11.

  A quarter wavelength plate 51, a polarizing plate 86, and an optical path control film (light scattering layer) 52 are arranged in this order on the panel outer side (observer side) of the counter substrate 4. A quarter wavelength plate 50 and a polarizing plate 87 are arranged in this order on the outside of the panel of the TFT substrate 2. The polarizing axes of both polarizing plates 86 and 87 are orthogonal to each other. A backlight unit 88 is disposed further outside the polarizing plate 87.

  When no voltage is applied, the liquid crystal molecules are aligned substantially perpendicular to the substrate surface, so that the liquid crystal 6 does not exhibit an optical effect on light. When the reflective display is performed, the incident external light is reflected by the reflection plate 54. Here, the light that has passed through the polarizing plate 86 passes through the quarter-wave plate 51 and enters the liquid crystal 6, is reflected by the reflective electrode 16, and then passes through the quarter-wave plate 51 again. That is, when the light passes through the quarter-wave plate 51 twice, its polarization state is rotated by 90 °. Therefore, this light is absorbed by the polarizing plate 86. For this reason, black is displayed in the reflection mode.

  Further, when performing transmissive display, the light transmitted through the polarizing plate 87 on the backlight unit 88 side is transmitted through the ¼ wavelength plate 50 and is incident on the liquid crystal 6, and is transmitted through the ¼ wavelength plate 51. That is, when the light passes through the quarter-wave plates 50 and 51 twice, its polarization state is rotated by 90 °. Therefore, this light is absorbed by the polarizing plate 86 on the viewer side. For this reason, black is displayed in the transmission mode.

  On the other hand, in a state where a predetermined voltage is applied, the liquid crystal molecules are inclined with respect to the substrate surface. For this reason, the liquid crystal 6 exhibits birefringence, which is an optical effect, and the polarization state of transmitted light changes. When performing reflective display, the incident external light is transmitted through the liquid crystal 6 to change its polarization state, and is transmitted through the polarizing plate 86. For this reason, white or gray is displayed in the reflection mode. When performing transmissive display, the light incident from the backlight unit 88 is also transmitted through the liquid crystal 6 to change its polarization state, and is transmitted through the polarizing plate 86. For this reason, white or gray is displayed in the transmission mode.

  In this embodiment, since an electrode such as a storage capacitor electrode formed on a general TFT substrate 2 is used as the reflector 54, there is no additional manufacturing process. Here, when the backlight unit 88 is lit as a transmissive type, the reflection of external light on the reflection plate 54 is hardly noticed. This is because no voltage is applied when black is displayed in the transmissive mode and when black is displayed in the reflective mode, and there is no reflection of external light when black is displayed in the transmissive mode. It is.

  As the optical path control film 52, a film that scatters only light incident at an incident angle within a predetermined range is used. For example, light incident from the sun is scattered by the optical path control film 52 and reflected by the reflection plate 54. The reflected light is used for display and emitted to the viewer side. Thereby, even in the case of a light source such as the sun, for example, display can be performed using light reflected by the reflection plate 54 while avoiding surface reflection. It is desirable that the reflected light is not scattered when it passes through the optical path control film 52 again.

  Hereinafter, description will be made using specific examples.

(Example 1-1)
A liquid crystal display device according to Example 1-1 of this embodiment will be described with reference to FIGS. FIG. 2 shows a schematic configuration of the liquid crystal display device according to the present embodiment. As shown in FIG. 2, the liquid crystal display device includes a TFT substrate 2 including a gate bus line and a drain bus line formed so as to cross each other via an insulating film, and a TFT and a pixel electrode formed for each pixel. have. Further, the liquid crystal display device includes a counter substrate 4 on which a common electrode is formed, and a liquid crystal (not shown) sealed between both the substrates 2 and 4.

  The TFT substrate 2 includes a gate bus line driving circuit 80 on which driver ICs for driving a plurality of gate bus lines are mounted, and a drain bus line driving circuit 82 on which driver ICs for driving a plurality of drain bus lines are mounted. Is provided. These drive circuits 80 and 82 are configured to output scanning signals and data signals to predetermined gate bus lines or drain bus lines based on predetermined signals output from the control circuit 84. A polarizing plate 86 is disposed on the substrate surface opposite to the element formation surface of the TFT substrate 2, and a backlight unit 88 is attached to the surface of the polarizing plate 86 opposite to the TFT substrate 2. On the other hand, a polarizing plate 87 arranged in crossed Nicols with the polarizing plate 86 is attached to the surface of the counter substrate 4 opposite to the common electrode forming surface.

  FIG. 3 shows a configuration of almost one pixel of the liquid crystal display device according to the present embodiment. As shown in FIG. 3, on the TFT substrate 2 of the liquid crystal display device, a plurality of gate bus lines 12 extending in the left-right direction in the drawing are formed substantially in parallel with each other (two are shown in FIG. 3). A plurality of drain bus lines 14 that cross the gate bus line 12 through an insulating film (not shown) and extend in the vertical direction in the drawing are formed substantially parallel to each other (two are shown in FIG. 3). A TFT 20 is formed in the vicinity of each intersection position of the gate bus line 12 and the drain bus line 14. A region surrounded by the gate bus line 12 and the drain bus line 14 is a pixel region. A storage capacitor bus line 18 extending substantially parallel to the gate bus line 12 is formed across substantially the center of the pixel region. A storage capacitor electrode 19 is formed for each pixel region on the storage capacitor bus line 18.

  In the pixel region, a pixel electrode 16 made of a transparent conductive film such as ITO (Indium Tin Oxide) is formed. The pixel electrode 16 has a rectangular outer periphery, and is separated by a plurality of electrode units 60 smaller than the pixel region, electrode extraction portions (slits) 62 formed between adjacent electrode units 60, and slits 62. It has the connection electrode 64 which electrically connects the electrode unit 60 mutually. In the configuration shown in FIG. 3, twelve electrode units 60 having a substantially square outer periphery are formed in one pixel. On the outer periphery of the electrode unit 60, a plurality of spaces 66 are formed which are cut from each end substantially parallel to the gate bus line 12 or the drain bus line. On the other hand, on the counter substrate, a BM 68 that shields an area outside the pixel area is formed.

  FIG. 4 shows a configuration of a conventional liquid crystal display device for comparison with the present embodiment. Unlike the conventional liquid crystal display device shown in FIG. 4, the liquid crystal display device according to this embodiment is made of the storage capacitor electrode 19 (or the same formation material as the gate electrode of the TFT 20) made of the same formation material as the source / drain electrodes of the TFT 20. This is characterized in that no BM 68 ′ is formed on the storage capacitor bus line 18). In the conventional configuration, the BM 68 ′ is provided in order to prevent external light from being reflected by the storage capacitor electrode 19 (or the storage capacitor bus line 18), but in this embodiment, the storage capacitor electrode 19 (or storage capacitor) is provided. A capacitive bus line 18) is used as a reflector.

  FIG. 5 shows a modification of the configuration of the liquid crystal display device according to this embodiment. As shown in FIG. 5, in this modification, in addition to the storage capacitor electrode 19 (or storage capacitor bus line 18) being used as a reflector, a circular reflector 54 is separately provided in the pixel region. ing. The reflection plate 54 is made of the same material as that of the gate electrode or source / drain electrode of the TFT 20, and is disposed so as to overlap the center of the electrode unit 60 when viewed in the direction perpendicular to the substrate surface. Further, the reflecting plate 54 is in an electrically floating state. Although not shown, Lumisty (registered trademark) manufactured by Sumitomo Chemical Co., Ltd. was used for the optical path control film 52.

(Example 1-2)
Next, a liquid crystal display device according to Example 1-2 of this embodiment will be described with reference to FIGS. FIG. 6 shows a configuration of almost one pixel of the liquid crystal display device according to the present embodiment. FIG. 7 shows a configuration of a conventional liquid crystal display device for comparison with the present embodiment. In this embodiment, unlike the conventional liquid crystal display device, the BM 68 ′ on the storage capacitor electrode 19 made of the same material as that of the source / drain electrodes of the TFT 20 is not formed. Further, in this embodiment, the alignment regulating protrusion 70 is provided on the counter substrate side. The protrusion 70 is disposed substantially at the center of the electrode unit 60. Further, the projection 70 on the storage capacitor electrode 19 is formed in a cross shape. As a result, liquid crystal alignment is performed on the storage electrode 19 used as a reflector, and a reflective display with excellent viewing angle characteristics can be realized.

  FIG. 8 shows the arrangement of polarizing plates and the like of the liquid crystal display device according to this example. As shown in FIG. 8, a polarizing plate (for example, SEG1425, AG150) 86 and a polarizing plate (for example, SEG1425) 87 that are arranged in crossed Nicols with respect to the liquid crystal layer 6 are disposed. A quarter wave plate 51 is disposed between the liquid crystal layer 6 and the polarizing plate 86. A quarter-wave plate 50 is disposed between the liquid crystal layer 6 and the polarizing plate 87. For the quarter-wave plates 50 and 51, for example, an ARTON film having an in-plane retardation of 140 nm is used. A TAC film 72 having a negative phase difference is disposed between the liquid crystal layer 6 and the quarter wavelength plate 51 in order to improve viewing angle characteristics. Further, an optical film 74 such as PCF 350 is disposed outside the polarizing plate 87. The upper side in the figure is the observer side, and the lower side in the figure is the light source side.

  The angle formed by the optical axis (slow axis) 91 of the quarter-wave plate 50 and the absorption axis 90 of the polarizing plate 87 is approximately 45 °. That is, when the light emitted from the light source passes through the polarizing plate 87 and the quarter-wave plate 50 in this order, it becomes circularly polarized light. The angle formed by the optical axis 94 of the quarter-wave plate 51 and the absorption axis 95 of the polarizing plate 86 is approximately 45 °. The optical axes 91 and 94 of the quarter-wave plates 50 and 51 are substantially orthogonal to each other. In order to realize the symmetry of the viewing angle and to optimize the viewing angle characteristics in the vertical and horizontal directions with respect to the display screen, the polarizing plates 86 and 87 and the quarter wave plates 50 and 51 are arranged as follows. ing.

  The absorption axis 90 of the polarizing plate 87 is arranged in a direction of 150 ° counterclockwise with respect to the right side of the display screen. The optical axis 91 of the quarter-wave plate 50 is arranged in a 15 ° direction counterclockwise with respect to the right side of the display screen. The optical axis 94 of the quarter-wave plate 51 is arranged in a 105 ° direction counterclockwise with respect to the right side of the display screen. The absorption axis 95 of the polarizing plate 86 is arranged in a direction of 60 ° counterclockwise with respect to the right side of the display screen.

(Example 1-3)
Next, a liquid crystal display device according to Example 1-3 of this embodiment will be described with reference to FIG. In the embodiments so far, the same voltage is applied to the reflection type and the transmission type. However, light passes only once in the transmission region, whereas light passes twice in the reflection region. For this reason, the optical effect in the reflective area is twice that of the transmissive area. For example, when white is displayed in the transmissive area, the reflective area is yellowish. In the case of transmissive display, the reflection region is hidden behind the storage capacitor electrode 19 and cannot be seen. However, in the case of reflective display, this yellowish phenomenon becomes a problem. For this reason, in this embodiment, the drive voltage is lowered when performing reflective display.

  FIG. 9 is a block diagram showing a driving method of the liquid crystal display device according to the present embodiment. Switching between the transmission type and the reflection type may be performed by the user or in conjunction with ON / OFF of the backlight, both of which are shown in FIG. When used as a transmission type, the maximum drive voltage is set to, for example, 5 V, which is the same as a normal drive voltage. When used as a reflection type, the maximum drive voltage is set to, for example, 3 V, which is lower than the normal drive voltage. These drive voltages are selected so that Δn in the reflective type is approximately half of Δn in the transmissive type when displaying the same gradation. Further, only by adjusting the voltage, the gradation characteristics are different between the transmissive display and the reflective display. For this reason, the relationship between the gradation and the applied voltage is adjusted as appropriate so that the gradation characteristics of the transmissive display and the reflective display are the same.

(Example 1-4)
Next, a liquid crystal display device according to Example 1-4 of the present embodiment and a manufacturing method thereof will be described with reference to FIGS. FIG. 10 shows a partial configuration of a pixel of the liquid crystal display device according to this embodiment. As shown in FIG. 10, an opening in which a protective film (not shown) is opened over most of the storage capacitor electrode 19 made of a laminated film in which aluminum (Al) and titanium (Ti) are formed in this order. A part (contact hole) 76 is formed. In the opening 76, the upper Ti layer of the storage capacitor electrode 19 is also removed by etching, and the surface of the lower Al layer is exposed as a reflective surface. Further, the electrode unit 60 (pixel electrode 16 or connection electrode 64 in FIG. 10) formed on the protective film is electrically connected to the storage capacitor electrode 19 through the opening 76.

  The storage capacitor electrode 19 and the opening 76 are formed as follows. On the insulating film formed on the entire surface of the gate bus line and the storage capacitor bus line, an Al layer and a Ti layer are formed in this order to form a laminated film. Next, the laminated film is patterned into a predetermined shape to form the storage capacitor electrode 19. Next, a protective film, which is an insulating layer, is formed on the entire surface of the substrate on the storage capacitor electrode 19. Next, the protective film on the storage capacitor electrode 19 is removed to form an opening 76, and then the Ti layer exposed through the opening 76 is removed by etching. As a result, the Al layer of the storage capacitor electrode 19 is exposed. Thereafter, ITO is formed and patterned, and for example, the pixel electrode 16 or the connection electrode 64 in FIG. 10 is formed so as to cover the exposed Al layer.

  According to this embodiment, the Al layer surface is exposed at most of the storage capacitor electrode 19 functioning as a reflector. The reflectance of Al is much higher than that of Ti. For this reason, the high reflectance of Al can be used, and high display characteristics can be obtained during reflective display.

  Next, a modification of the configuration of the liquid crystal display device according to this embodiment will be described. In the configuration as shown in FIG. 10, the ITO layer and the Al layer are in direct contact. For this reason, the problem that corrosion by a battery effect may arise arises. FIG. 11 shows a configuration of a liquid crystal display device according to this modification in which this problem does not occur. As shown in FIG. 11, in the present modification, a reflection plate 54 is formed so as not to overlap the electrode unit 60 made of ITO or the connection electrode 64 when viewed in the direction perpendicular to the substrate surface. The reflection plate 54 is made of the same material as that of the gate electrode of the TFT 20 or the same material as that of the source / drain electrodes. Further, the reflecting plate 54 is in an electrically floating state. The reflection plate 54 is formed, for example, by removing the upper Ti layer in a step of forming a contact hole on the source electrode of the TFT 20 or the storage capacitor electrode 19 after the laminated film of the Al layer and the Ti layer is patterned. ing. Therefore, the reflecting surface of the reflecting plate 54 is formed of an Al layer. In this modification, it is possible to prevent the ITO layer and the Al layer from reacting. The liquid crystal on the reflection plate 54 is driven by an oblique electric field from the electrode unit 60.

  As described above, according to the present embodiment, a transflective liquid crystal display device capable of displaying in both transmissive and reflective modes can be manufactured using substantially the same manufacturing process as the transmissive liquid crystal display device. . Thereby, the manufacturing cost does not increase, and a low-cost transflective liquid crystal display device can be realized.

[Second Embodiment]
Next, a liquid crystal display device according to a second embodiment of the present invention will be described with reference to FIGS. The transflective (reflection / transmission type) liquid crystal display device performs reflection display using external light in a bright environment, and performs transmission display using a backlight in a dark environment. The reflective liquid crystal display device is difficult to see in a dark environment, and the transmissive liquid crystal display device is difficult to see in a bright environment. A transflective liquid crystal display device is widely used in portable information terminals and the like because it can select a display that is easy to see in environments with different brightness.

  In the reflection type liquid crystal display device, when the reflection film (reflection electrode) is a smooth mirror surface, the display becomes bright in the regular reflection region, and the display becomes dark in other regions. For this reason, the viewing angle dependency is strong and the display has a metallic luster. In view of this, a technique is known in which reflected light is diffused by forming irregularities having a dot-like planar shape on the surface of a reflective film to realize a display without metallic luster (see, for example, Patent Document 4). In the above-described reflective liquid crystal display device, since the reflecting surface is oriented in a random direction, when light is incident from all directions, it can be efficiently reflected to the viewer side, and a bright display can be obtained. However, when light enters from a specific direction as in an indoor environment, there is a problem that the light use efficiency is low and the display becomes dark.

  In a transmissive liquid crystal display device, a technique for forming an alignment control inclined portion by partially raising or sinking a contact surface with a liquid crystal layer on at least one of transparent electrodes, and controlling the alignment of liquid crystal with the alignment control inclined portion Is known (see, for example, Patent Document 5). In the transmissive liquid crystal display device, as shown in FIGS. 12 and 13, the orientation direction of the liquid crystal molecules 8 (indicated by the arrow A) by the orientation control inclined portion 78 and the orientation direction of the liquid crystal molecules 8 by the electric field distortion (arrow B). ), The orientation of the liquid crystal 6 is not stable, causing a problem that alignment failure occurs and the transmittance decreases.

  In a transflective liquid crystal display device, a technique is known in which a reflective portion and a transmissive portion are divided into one pixel and the electrode surface of the reflective portion is formed in a continuous wave shape (see, for example, Patent Document 6). ). In the above-described transflective liquid crystal display device, in addition to the problems that occur in the above-described reflective liquid crystal display device, the orientation angle of the liquid crystal cannot be divided within the pixel, so that the viewing angle characteristics particularly in the transmissive portion are degraded. Occurs.

  An object of the present embodiment is to provide a liquid crystal display device capable of obtaining good display characteristics in both transmission and reflection modes.

  In this embodiment mode, in a transflective liquid crystal display device, linear protrusions (protrusion rows whose planar shape is a straight line) that are alignment regulating structures are provided on a transparent electrode of one substrate, and the line The reflective film is selectively formed on the surface including the inclined surface of the projection. Here, the orientation regulating structure may be a frame-like projection instead of a linear projection as long as the planar shape is a straight line (the same applies to the depressions described below). By selecting the vertical alignment as the alignment state of the liquid crystal, the liquid crystal anchored at the substrate interface during black display does not remain without being switched. For this reason, the contrast ratio becomes high and an easy-to-view display can be realized. In addition, by providing linear protrusions on the transparent electrode of the substrate on the backlight side and selectively forming a reflective film on the surface of the linear protrusions, the front direction and the oblique direction using the inclined surface of the linear protrusions Can be efficiently reflected to the viewer side. Furthermore, the loss of transmittance can be minimized by making the linear protrusions on the reflective region. In addition, since the thickness of the liquid crystal layer is different between the reflective region and the transmissive region, it is possible to match the gradation characteristics of the reflective display and the transmissive display.

  Further, this embodiment is characterized in that a depression extending linearly is provided on one substrate, and a reflective film is selectively formed on the surface including the inclined surface of the depression. That is, the orientation direction of the liquid crystal is controlled by a depression instead of the linear protrusion, and the cross-sectional shape and the thickness of the liquid crystal layer in the reflection region are opposite to the linear protrusion, but the same as the linear protrusion. The effect can be expected.

  Furthermore, the present embodiment is characterized in that a linear protrusion is provided on the transparent electrode of one substrate, and a reflective film is selectively formed below the linear protrusion. FIG. 14 is a cross-sectional view of a liquid crystal display device having the above configuration. As shown in FIG. 14, the reflective film 56 is formed below the linear protrusion 70. Since the linear protrusion 70 acts as a dielectric, the orientation direction of the liquid crystal molecules 8 (indicated by an arrow A) due to the inclined surface of the linear protrusion 70 and the orientation direction of the liquid crystal molecules 8 due to an electric field distortion (indicated by an arrow B). The alignment of the liquid crystal 6 is more stable.

  Furthermore, in the present embodiment, the alignment regulating structures such as linear protrusions and depressions extend in a direction inclined by approximately 45 ° with respect to the pixel electrode edge, a substantially parallel direction, or a substantially orthogonal direction. It is characterized by being formed. Thereby, the light incident from these directions can be efficiently reflected to the viewer side.

  In addition, this embodiment is characterized in that the reflective film and the transparent electrode are electrically separated. For example, if a voltage can be applied only to the reflective film during reflective display and a voltage can be applied only to the transparent electrode during transmissive display, an oblique electric field can be generated at the boundary between the transmissive region T and the reflective region R. In other words, the alignment orientation of the liquid crystal can be aligned with the orientation orthogonal to the boundary portion. In addition, the reflective film and the transparent electrode having different ionization tendencies can be insulated, and deterioration due to electrolytic corrosion can be prevented.

  15 and 16 are cross-sectional views of the liquid crystal display device having the above-described configuration. FIG. 15 shows a state in which a voltage is applied to the pixel electrode 16 and no voltage is applied to the reflective film 56 on the linear protrusion 70. FIG. 16 shows a state where a voltage is applied to the reflective film 56 on the depression 71 and no voltage is applied to the pixel electrode 16. As shown in FIGS. 15 and 16, the orientation direction of the liquid crystal molecules 8 (indicated by an arrow A) due to the inclined surfaces of the linear protrusions 70 and the depressions 71 and the orientation direction of the liquid crystal molecules 8 due to electric field distortion (indicated by the arrow B) And the orientation of the liquid crystal 6 is more stable.

  Furthermore, the present embodiment is characterized in that the range of the average inclination angle of the inclined surface of the alignment regulating structure with respect to the substrate surface is approximately 0 ° or more and less than 20 °. FIG. 17 shows the relationship between the light emitted in the front direction and the average inclination angle θ of the inclined surface of the reflective film 56. The light reflected in the front direction by the inclined surface of the reflective film 56 enters from an oblique direction, and the incident angle depends on the inclination angle of the inclined surface. The refractive index of the member constituting the transflective liquid crystal display device is approximately 1.5, and the maximum incident angle θc of light incident on the reflective film 56 is approximately 40 ° from Snell's law. Since incident light is specularly reflected by the reflection film 56, in order to reflect light incident at an incident angle of 0 ° to 40 ° in the front direction, the inclined angle of the inclined surface needs to be 0 ° or more and less than 20 °. . However, since the inclination angle of the inclined surface changes continuously, if the average inclination angle indicating the average value of the inclination angle distribution is within this range, the obliquely incident light can be efficiently reflected in the front direction. .

  Furthermore, in this embodiment, another alignment regulating structure (third alignment regulating structure) is formed in the gap portion of the alignment regulating structure extending in parallel on one substrate. It is characterized by. FIG. 18 is a cross-sectional view of a liquid crystal display device having the above configuration. As shown in FIG. 18, when the reflective film 56 is electrically connected to the pixel electrode 16, the reflective film 56 and the linear protrusion 70 function as conductive protrusions. In this case, as described above, the orientation direction of the liquid crystal molecules 8 due to the inclined surface is opposite to the orientation direction of the liquid crystal molecules 8 due to the electric field distortion, so that the orientation of the liquid crystal 6 is not stable and alignment failure occurs. Therefore, a slit 62 is formed in the gap between adjacent linear protrusions 70. Thereby, the alignment regulating force is applied in the substrate plane direction, and the liquid crystal alignment on the reflective film 56 and the linear protrusion 70 is aligned in the direction of electric field distortion. The alignment regulating structure in which the reflective film 56 is not formed in the upper layer functions as a dielectric. For this reason, the orientation direction of the liquid crystal molecules 8 due to the inclined plane and the orientation direction of the liquid crystal molecules 8 due to the electric field distortion coincide, and the orientation of the liquid crystal 6 is stabilized.

  In addition, this embodiment is characterized in that a slit is formed by removing a part of the reflective film on the alignment regulating structure. FIG. 19 is a cross-sectional view of a liquid crystal display device having the above configuration. As shown in FIG. 19, the reflective film 56 on the substantially flat surface of the linear protrusion 70 is removed, and a slit 62 is formed. Further, in the present embodiment, another alignment regulating structure (second alignment regulating structure) is formed on the other substrate in the region facing the alignment regulating structure via the liquid crystal. It is characterized by. FIG. 20 is a cross-sectional view of a liquid crystal display device having the above configuration. As shown in FIG. 20, a slit 62 is formed on the counter substrate 4 in a region facing the depression 71. These slits 62 apply an alignment regulating force in the direction perpendicular to the substrate to align the liquid crystal alignment on the reflective film 56 and the linear protrusions 70 or on the reflective film 56 and the depressions 71 in the direction of electric field distortion. Thereby, the alignment of the liquid crystal 6 is stabilized.

  Furthermore, the present embodiment is characterized in that the linear protrusion has a convex cross-sectional shape and is made of a transparent material having a higher refractive index than liquid crystal. FIG. 21 is a partial cross-sectional view of a liquid crystal display device having the above configuration. As shown in FIG. 21, the reflective film 56 is formed below the linear protrusion 70. The linear protrusion 70 has a convex (trapezoidal) cross-sectional shape and is made of a transparent resin having a refractive index higher than that of the liquid crystal 6.

  FIG. 22 is a cross-sectional view of a liquid crystal display device in which the linear protrusions 70 have a rectangular cross-sectional shape and are formed of a transparent resin having substantially the same refractive index as the liquid crystal 6. FIG. 23 is a cross-sectional view of a liquid crystal display device in which the linear protrusions 70 have a rectangular cross-sectional shape and are formed of a transparent resin having a refractive index higher than that of the liquid crystal 6. As shown in FIG. 22 and FIG. 23, when the cross-sectional shape of the linear protrusion 70 is rectangular, the incident angle θ1 and the outgoing angle θ2 are substantially equal regardless of the refractive index of the forming material. turn into. On the other hand, as shown in FIG. 21, when the linear protrusion 70 has a convex cross-sectional shape and is formed of a transparent resin having a refractive index larger than that of the liquid crystal 6, the exit angle θ2 with respect to the reflective film 56 is reflected. It becomes smaller than the incident angle θ1 with respect to the film 56. Therefore, light incident from an oblique direction is reflected in the front direction.

Hereinafter, description will be made using specific examples.
(Example 2-1)
A liquid crystal display device according to Example 2-1 of this embodiment will be described with reference to FIGS. FIG. 24 shows the arrangement of the reflective protrusions of the liquid crystal display device according to this example. FIG. 25 is a photograph showing the configuration of the liquid crystal display device according to this example. As shown in FIGS. 24 and 25, on the TFT substrate 2, a linear projection 70 and a reflective film 56 on the upper layer are formed as reflective projections. The linear protrusion 70 is formed on the pixel electrode 16 using a resist (manufactured by Shipley Far East). The cross-sectional shape of the linear protrusion 70 is convex, the average inclination angle is 8 °, and the peak height is 1.5 μm. The linear protrusion 70 is formed so as to be substantially parallel to the end of the pixel electrode 16 or at an angle of about 45 °. The reflection film 56 is selectively formed on the linear protrusion 70. The reflective film 56 is formed electrically independently for each pixel and is electrically connected to each pixel electrode 16. In addition, a slit 62 is formed in a gap between adjacent linear protrusions 70. Both the linear protrusion 70 and the slit 62 are formed on the TFT substrate 2.

  After the TFT substrate 2 and the counter substrate 4 were formed, a vertical alignment film (manufactured by JSR) was applied to both the substrates 2 and 4. Thereafter, spacers (made by Sekisui Fine Chemical Co., Ltd.) having a bead diameter of 4.5 μm were dispersed to bond both the substrates 2 and 4 to form an empty panel. A liquid crystal having a negative dielectric anisotropy (manufactured by Merck Japan) was injected into the empty panel to produce a liquid crystal display element. A right-handed circularly polarizing plate (polarizing plate and quarter-wave plate) and a left-handed circularly polarizing plate are bonded to both surfaces of the liquid crystal display element so that the slow axes of the quarter-wave plates are orthogonal to each other, thereby transflective liquid crystal A display device was produced. Orientation observation was performed in both reflection and transmission display modes. FIG. 26 is an orientation photograph when white is displayed in the reflection mode, and FIG. 27 is an orientation photograph when white is displayed in the transmission mode. In each display mode, no orientation failure was observed. This is because the formation of the slit 62 in the gap portion of the linear protrusion 70 causes the alignment regulating force to act in the substrate parallel direction and stabilizes the alignment direction.

  28 and 29 are graphs showing the results of measuring the reflection characteristics of the liquid crystal display device according to this example. FIG. 28 shows the change in reflectance with respect to the change in azimuth. The horizontal axis represents the azimuth angle, and the vertical axis represents the reflectance. A line A1 shows the reflection characteristic of the liquid crystal display device according to this embodiment, and a line A2 shows the reflection characteristic of the conventional liquid crystal display device in which an Al mirror-like reflection film is formed. Light was incident from a polar angle of 30 ° and received at a polar angle of 0 °. FIG. 29 shows a change in reflectance with respect to a change in incident angle (polar angle). The horizontal axis represents the incident angle and the inclination angle of the corresponding inclined surface, and the vertical axis represents the reflectance. The line B1 shows the reflection characteristics when light is incident on the liquid crystal display device according to the present embodiment from the direction of 45 ° azimuth, and the line B2 is from the direction of 90 ° azimuth to the liquid crystal display device according to the present embodiment. The reflection characteristics when light is incident are shown. A line B3 indicates the reflection characteristic of a conventional liquid crystal display device in which an Al mirror-like reflection film is formed.

  As shown in FIG. 28, when the light is incident from the 45 ° azimuth, the 90 ° azimuth, and the 135 ° azimuth, the azimuth angle dependency that the reflectance is increased occurs. Further, as shown in FIG. 29, it was found that as the incident angle of light becomes smaller, the reflectance becomes higher and the incident angle dependency is increased, and 15 to 30% of light is reflected in the front direction even at a considerably large incident angle. In the present embodiment, the reflective film 56 and the linear protrusion 70 are formed so as to be substantially parallel to the edge of the pixel electrode 16 or at an angle of about 45 °. If formed so as to be substantially orthogonal to the edge of the pixel electrode 16, the reflectance can be increased even if light is incident from 0 ° azimuth and 180 ° azimuth.

  FIG. 30 is a graph showing the results of measuring the transmission characteristics of the liquid crystal display device according to this example. The horizontal axis represents voltage, and the vertical axis represents transmittance. A line C1 indicates the transmission characteristics of the transflective liquid crystal display device according to this embodiment, and a line C2 indicates the transmission characteristics of the conventional transmission type liquid crystal display device in which the reflective film 56 is not formed. Light was incident at a polar angle of 180 ° and received at a polar angle of 0 °. As shown in FIG. 30, in the liquid crystal display device according to the present embodiment, since the reflective film 56 is formed on the linear protrusions 70, the amount of light transmitted through the linear protrusions 70 as compared with the conventional transmissive liquid crystal display device. The transmittance is reduced by that amount. However, in the vicinity of the saturation voltage, the rate of decrease in transmittance is small, and it has transmission characteristics comparable to that of a transmissive liquid crystal display device. Therefore, according to the present embodiment, it is possible to realize a transflective liquid crystal display device capable of performing reflective display while suppressing a decrease in transmission characteristics.

(Example 2-2)
Next, a liquid crystal display device according to Example 2-2 of this embodiment will be described. In this embodiment, a recess 71 is formed instead of a part of the protrusion 70, and the reflective film 56 and the pixel electrode 16 are electrically separated. In addition, a slit 62 was formed on the counter substrate 4 in a region facing the gaps between adjacent protrusions 70 or depressions 71 with the liquid crystal 6 interposed therebetween. A liquid crystal display device similar to that of Example 2-1 was produced except for the above. The recess 71 was formed using a resist so that the cross-sectional shape was concave, the average inclination angle was 8 °, and the peak height difference was 1.5 μm. Further, a reflective film 56 is formed on the protrusion 70 and the depression 71 so as to be electrically separated from the pixel electrode 16. Orientation observation was performed in both reflection and transmission display modes. As a result, in the transmissive display in the vicinity of the protrusion 70 and in the reflective display in the vicinity of the depression 71, an alignment state without alignment defects was obtained as in the alignment photographs shown in FIGS. The reflective film 56 on the projection 70 and the depression 71 and the pixel electrode 16 are electrically separated and driven separately, so that the orientation azimuth by the inclined surface of the projection 70 and the depression 71 and the orientation azimuth by the electric field distortion are the same. It was confirmed that the alignment of the liquid crystal 6 was stable.

(Example 2-3)
Next, a liquid crystal display device according to Example 2-3 of this embodiment will be described. In this embodiment, the slit 62 is formed in the reflective film 56 on the protrusion 70. Further, the slit 62 was formed on the counter substrate 4 in the region facing the liquid crystal 6 in the gap portion between the adjacent projections 70, and the slit 62 was not formed on the TFT substrate 2 in the gap portion of the projection 70. Except for the above, a liquid crystal display device similar to that of Example 2-1 was produced. Orientation observation was performed in both reflection and transmission display modes. As a result, in each display mode, an alignment state without alignment failure was obtained as in the alignment photographs shown in FIGS. Since the slit 56 was formed in the reflective film 56 on the protrusion 70, it was confirmed that the alignment azimuth by the inclined surface of the protrusion 70 coincided with the alignment azimuth by the electric field distortion, and the alignment of the liquid crystal 6 was stabilized.

(Example 2-4)
Next, a liquid crystal display device according to Example 2-4 of this embodiment will be described. In this example, a liquid crystal display device was produced in the same manner as in Example 2-2 except that the reflective film 56 on the depression 71 and the pixel electrode 16 were electrically connected. Orientation observation was performed in both reflection and transmission display modes. As a result, in each display mode, an alignment state without alignment failure was obtained as in the alignment photographs shown in FIGS. Since the slits 56 are formed on the counter substrate 4 in a region facing the depression 71 via the liquid crystal 6, the orientation direction due to the inclined surface of the depression 71 coincides with the orientation direction due to electric field distortion, and the orientation of the liquid crystal 6 is stabilized. Was confirmed.

(Example 2-5)
Next, a liquid crystal display device according to Example 2-5 of the present embodiment will be described. In this embodiment, a projection 70 having a convex cross-sectional shape is formed using a transparent resin (manufactured by JSR) having a refractive index of 1.7 that is higher than the refractive index of liquid crystal, and a reflective film 56 is selectively formed below the projection 70. Formed. Further, the slit 62 was formed on the counter substrate 4 in the region facing the liquid crystal 6 in the gap portion between the adjacent projections 70, and the slit 62 was not formed on the TFT substrate 2 in the gap portion of the projection 70. Except for the above, a liquid crystal display device similar to that of Example 2-1 was produced. Orientation observation was performed in both reflection and transmission display modes. As a result, in each display mode, an alignment state without alignment failure was obtained as in the alignment photographs shown in FIGS. By selectively forming the reflective film 56 below the protrusion 70, the protrusion 70 and the reflective film 56 function as insulating protrusions. For this reason, it was confirmed that the alignment azimuth by the inclined surface of the protrusion 70 coincided with the alignment azimuth by the electric field distortion, and the alignment of the liquid crystal 6 was stabilized.

  As described above, the liquid crystal display device according to the present embodiment can realize a bright reflective display with almost no loss of transmittance, and can realize a transmissive display with a wide viewing angle range. As a result, a liquid crystal display device that is easy to see in all environments can be realized.

The liquid crystal display device and the manufacturing method thereof according to the first embodiment described above can be summarized as follows.
(Appendix 1)
A pair of opposed substrates;
A liquid crystal sealed between the pair of substrates and aligned substantially perpendicular to the substrate when no voltage is applied;
A pair of quarter wave plates respectively disposed outside the pair of substrates;
A pair of polarizing plates respectively disposed outside the pair of quarter-wave plates;
A reflective region having a substantially flat reflective surface and having a reflector that reflects light incident from one side of the pair of substrates; and light incident from the other side of the pair of substrates. A liquid crystal display device comprising: a pixel region including a transmissive region that is transmissive to the side.

(Appendix 2)
In the liquid crystal display device according to appendix 1,
The liquid crystal display device further comprising a light scattering layer disposed on one outer side of the pair of substrates.

(Appendix 3)
In the liquid crystal display device according to attachment 2,
The light scattering layer scatters only light incident at an incident angle within a predetermined range.

(Appendix 4)
In the liquid crystal display device according to any one of appendices 1 to 3,
The liquid crystal display device, wherein the reflection plate is formed of the same material as the electrode of the thin film transistor formed for each pixel region.

(Appendix 5)
In the liquid crystal display device according to any one of appendices 1 to 4,
The liquid crystal display device, wherein the reflector is one electrode of a storage capacitor formed for each pixel region.

(Appendix 6)
In the liquid crystal display device according to any one of appendices 1 to 5,
The liquid crystal display device, wherein the reflection plate is disposed so as to overlap a pixel electrode formed in each pixel region when viewed in a direction perpendicular to a substrate surface.

(Appendix 7)
In the liquid crystal display device according to appendix 6,
The liquid crystal display device, wherein the reflection plate is electrically connected to the pixel electrode.

(Appendix 8)
In the liquid crystal display device according to appendix 6,
The liquid crystal display device, wherein the reflector is electrically separated from the pixel electrode.

(Appendix 9)
In the liquid crystal display device according to any one of appendices 1 to 5,
The liquid crystal display device, wherein the reflector is disposed so as not to overlap a pixel electrode formed in each pixel region when viewed in a direction perpendicular to the substrate surface.

(Appendix 10)
The liquid crystal display device according to any one of appendices 1 to 9,
At least a part of the reflecting surface is made of aluminum.

(Appendix 11)
In the liquid crystal display device according to appendix 10,
The reflection plate has a conductive layer made of other than aluminum and an aluminum layer formed in a lower layer of the conductive layer, the surface of which is exposed in the region where the conductive layer is removed. apparatus.

(Appendix 12)
In the liquid crystal display device according to appendix 11,
A liquid crystal display device, wherein a transparent electrode is formed to cover the aluminum layer.

(Appendix 13)
In the liquid crystal display device according to appendix 11 or 12,
The liquid crystal display device, wherein the conductive layer is a titanium layer.

(Appendix 14)
Forming an aluminum layer and a conductive layer made of other than aluminum in this order;
Patterning the conductive layer and the aluminum layer;
Forming an insulating layer on the patterned conductive layer;
Removing the insulating layer on the conductive layer to form an opening, and then removing the conductive layer exposed through the opening to expose the aluminum layer to form a reflective surface of a reflector. A method for manufacturing a liquid crystal display device, comprising:

(Appendix 15)
In the method for manufacturing a liquid crystal display device according to appendix 14,
A method for manufacturing a liquid crystal display device, further comprising forming a transparent electrode so as to cover the aluminum layer.

The liquid crystal display device according to the second embodiment described above can be summarized as follows.
(Appendix 16)
A pair of opposed substrates;
A liquid crystal sealed between the pair of substrates and having negative dielectric anisotropy;
A pixel electrode formed for each pixel region of the pair of substrates;
An alignment regulating structure in which a planar shape is a straight line on at least one of the pair of substrates;
And a reflective film selectively formed on the alignment restricting structure including the inclined surface of the alignment restricting structure.

(Appendix 17)
In the liquid crystal display device according to attachment 16,
The liquid crystal display device, wherein the alignment regulating structure is a protrusion.

(Appendix 18)
In the liquid crystal display device according to appendix 17,
The liquid crystal display device, wherein the alignment regulating structure is a depression.

(Appendix 19)
In the liquid crystal display device according to attachment 18,
The liquid crystal display device further comprising: a second alignment regulating structure disposed to face the depression through the liquid crystal.

(Appendix 20)
The liquid crystal display device according to any one of appendices 16 to 19,
An average inclination angle of the inclined surface is generally not less than 0 ° and less than 20 °.

(Appendix 21)
The liquid crystal display device according to any one of appendices 16 to 20,
A liquid crystal display device further comprising a third alignment regulating structure formed in a gap between adjacent alignment regulating structures.

(Appendix 22)
In the liquid crystal display device according to any one of appendices 16 to 21,
A liquid crystal display device further comprising a slit from which a part of the reflective film is removed.

(Appendix 23)
A pair of opposed substrates;
A liquid crystal sealed between the pair of substrates and having negative dielectric anisotropy;
A pixel electrode formed for each pixel region of the pair of substrates;
An alignment regulating structure in which a planar shape is a straight line on at least one of the pair of substrates;
And a reflective film selectively formed in a lower layer of the alignment regulating structure.

(Appendix 24)
In the liquid crystal display device according to attachment 23,
The liquid crystal display device, wherein the alignment regulating structure is a protrusion.

(Appendix 25)
In the liquid crystal display device according to attachment 24,
The liquid crystal display device, wherein the protrusion has a convex cross-sectional shape and is made of a transparent material having a refractive index larger than that of the liquid crystal.

(Appendix 26)
26. The liquid crystal display device according to any one of appendices 16 to 25,
The liquid crystal display device, wherein the alignment regulating structure extends so as to be substantially parallel or substantially orthogonal to the pixel electrode edge or an angle of about 45 °.

(Appendix 27)
In the liquid crystal display device according to any one of appendices 16 to 26,
The liquid crystal display device, wherein the reflective film is electrically separated from the pixel electrode.

(Appendix 28)
In the liquid crystal display device according to any one of appendices 16 to 26,
The liquid crystal display device, wherein the reflective film is electrically connected to the pixel electrode.

2 TFT substrate 4 Counter substrate 6 Liquid crystal 10, 11 Glass substrate 12 Gate bus line 14 Drain bus line 16 Pixel electrode 18 Storage capacitor bus line 19 Storage capacitor electrode 20 TFT
30 Insulating film 42 Common electrode 50, 51 1/4 wavelength plate 52 Optical path control film 54 Reflecting plate 56 Reflecting film 60 Electrode unit 62 Slit 64 Connection electrode 66 Space 68 BM
70 Protrusion 71 Depression 72 TAC film 74 Optical film 76 Opening 78 Orientation control inclined part 80 Gate bus line drive circuit 82 Drain bus line drive circuit 84 Control circuit 86, 87 Polarizing plate 88 Backlight units 90, 95 Absorption shafts 91, 94 Optical axis

Claims (10)

A pair of opposed substrates;
A liquid crystal sealed between the pair of substrates and aligned substantially perpendicular to the substrate when no voltage is applied;
A pair of quarter wave plates respectively disposed outside the pair of substrates;
A pair of polarizing plates respectively disposed outside the pair of quarter-wave plates;
A reflection region including a reflection plate that reflects light incident from one side of the pair of substrates; and a transmission region that transmits light incident from the other side of the pair of substrates to one side of the pair of substrates. A liquid crystal display device having a pixel region,
The reflector is formed of the same material and the same layer as the electrode of the thin film transistor formed for each pixel region,
A transparent pixel electrode formed for each of the pixel regions is formed so as to cover the reflective plate when viewed in a direction perpendicular to the substrate surface.
An insulating layer that forms a protective film of the thin film transistor is formed in part on an upper portion of the reflecting plate, and the reflecting plate is exposed from an opening where the insulating layer is not formed. A liquid crystal display device, wherein the transparent pixel electrode is formed in contact with a plate. The liquid crystal display device according to claim 1, wherein the reflection plate is one electrode of a storage capacitor formed for each pixel region. The liquid crystal display device according to claim 1, further comprising a light scattering layer disposed on one outer side of the pair of substrates. 4. The liquid crystal display device according to claim 1, wherein at least a part of the reflecting plate is made of aluminum. 5. An aluminum layer and a conductive layer made of other than aluminum are formed as thin film transistor constituting electrodes,
The conductive layer and the aluminum layer are exposed from the opening from which the insulating layer has been removed, and in particular, the aluminum layer is exposed to form a reflective surface of the reflector. Item 5. The liquid crystal display device according to any one of Items 1 to 4. The liquid crystal display device according to claim 3, wherein the light scattering layer scatters only light incident at an incident angle within a predetermined range. The liquid crystal display device according to claim 1, wherein the reflecting plate is electrically connected to the transparent pixel electrode. The liquid crystal display device according to claim 1, wherein the reflector is electrically separated from the transparent pixel electrode. The liquid crystal display device according to claim 5, wherein the conductive layer is a titanium layer. The liquid crystal display device according to claim 1, wherein a material of the transparent electrode on the thin film transistor substrate is made of the same material as that of the transparent electrode on the counter substrate.

Images