JP4628837B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid crystal display device provided with a polarizing plate and a λ / 4 plate (retardation plate) and a method for manufacturing the same.

  A liquid crystal display device is advantageous in that it is thin and lightweight, can be driven at a low voltage and consumes less power, and is widely used in various electronic devices. In particular, an active matrix type liquid crystal display device in which a TFT (Thin Film Transistor) is provided as a switching element for each pixel is superior in terms of display quality to comparable to a CRT (Cathode-Ray Tube). Widely used in displays such as televisions and personal computers.

  A general liquid crystal display device has a structure in which liquid crystal is sealed between two substrates arranged to face each other. A TFT, a pixel electrode, and the like are formed on one substrate, and a color filter, a common (common) electrode, and the like are formed on the other substrate. Hereinafter, a substrate on which a TFT, a pixel electrode, and the like are formed is referred to as a TFT substrate, and a substrate disposed to face the TFT substrate is referred to as a counter substrate. A structure in which liquid crystal is sealed between a TFT substrate and a counter substrate is called a liquid crystal panel.

  The liquid crystal display device includes a transmissive liquid crystal display device that displays an image by light transmitted through a liquid crystal panel using a backlight as a light source, and a reflective liquid crystal that displays an image using reflection of external light (natural light or electric light). There are display devices and transflective liquid crystal display devices that use a backlight in dark places and display images using reflection of external light in bright places.

  The reflective liquid crystal display device has an advantage that power consumption is smaller than that of the transmissive liquid crystal display device because a backlight is unnecessary. Further, in a place where the surroundings are bright, an image is often seen more clearly with a reflective liquid crystal display device or a transflective liquid crystal display device using external light than with a transmissive liquid crystal display device using a backlight.

  Japanese Patent No. 3420663 describes a transflective liquid crystal display device in which a reflective electrode and a transparent electrode are provided in one pixel. As described in this patent publication, in a general transflective liquid crystal display device, a polarizing plate and a λ / 4 plate (retardation plate) are arranged on both sides of a liquid crystal panel, respectively. The polarizing plate is disposed with its absorption axes orthogonal to each other, and the λ / 4 plate is disposed with its slow axes orthogonal to each other. Japanese Patent No. 3031229 also describes a liquid crystal display device in which a polarizing plate and a λ / 4 plate are arranged on both sides of a liquid crystal panel.

  FIG. 1 is a schematic view showing the structure of a conventional transflective liquid crystal display device. As shown in FIG. 1, the transflective liquid crystal display device includes a liquid crystal panel 10, a backlight unit 20 disposed on the back side of the liquid crystal panel 10 (lower side in FIG. 1), and the liquid crystal panel 10. The two polarizing plates 14a and 14b arranged, the λ / 4 plate 15a arranged between the liquid crystal panel 10 and the polarizing plate 14a on the back side, the liquid crystal panel 10 and the front side (observer side: FIG. 1) In this case, the λ / 4 plate 15b is disposed between the polarizing plate 14b on the upper side). As described above, the polarizing plates 14a and 14b are arranged with their absorption axes orthogonal to each other. The λ / 4 plates 15a and 15b are arranged with their slow axes orthogonal to each other.

  The liquid crystal panel 10 is composed of two substrates 11 and 12 and a liquid crystal layer 13 made of liquid crystal (vertical alignment type liquid crystal) having negative dielectric anisotropy enclosed between them. In addition, a large number of pixels are arranged in a matrix on the liquid crystal panel 10, and each pixel has a reflective region in which a reflective electrode 17a made of a metal having high reflectivity such as Al (aluminum) is disposed, and ITO (Indium- And a transparent region in which a transparent electrode 17b made of a transparent conductor such as Tin Oxide is disposed. In the example shown in FIG. 1, a reflective electrode 17a and a transparent electrode 17b are provided on a substrate (TFT substrate) 11 on the back side. Further, a common electrode 18 common to each pixel is formed on the front substrate (counter substrate) 12.

  The backlight unit 20 includes a light source 21, a reflection plate 22, and a light guide plate 23. The light source 21 is disposed in the vicinity of the end face of the light guide plate 23, and the light emitted from the light source 21 enters the light guide plate 23 from the end face of the light guide plate 23 directly or after being reflected by the reflecting plate 22. For example, a reflective layer is provided on the back side of the light guide plate 23, and a scattering layer is provided on the front side. The light guide plate 23 uniformly outputs the light input from the end face toward the liquid crystal panel 10.

In the transflective liquid crystal display device configured as described above, when no voltage is applied between the pixel electrode (the reflective electrode 17a and the transparent electrode 17b) and the common electrode 18, black display (dark display) is obtained. When a predetermined voltage is applied between the common electrode 18 and the common electrode 18, white display (bright display) is obtained. By controlling the voltage applied between the pixel electrode and the common electrode 18, the amount of light emitted to the front side of the panel can be adjusted. A desired image can be displayed on the liquid crystal display device by controlling the voltage applied between the pixel electrode and the common electrode 18 for each pixel.
Japanese Patent No. 3410663 Japanese Patent No. 3031229

  However, the present inventors consider that the above-described conventional transflective liquid crystal display device has the following problems.

  FIG. 2 is a schematic diagram showing the light state during black display of a conventional transflective liquid crystal display device, and FIG. 3 is a schematic diagram showing the light state during white display. 2 and 3, the same components as those in FIG. 1 are denoted by the same reference numerals. 2 and 3, reference numeral 30 denotes liquid crystal molecules in the liquid crystal layer.

  Light from the front side of the panel (upper side in FIGS. 2 and 3) becomes linearly polarized light when passing through the polarizing plate 14b and is rotated in a certain direction by the λ / 4 plate 15b (left rotation in FIGS. 2 and 3). Converted into circularly polarized light. This light is reflected by the reflective electrode 17a, becomes circularly polarized light of reverse rotation (right rotation in FIGS. 2 and 3), and is converted into linearly polarized light by the λ / 4 plate 15b.

  At this time, as shown in FIG. 2, the liquid crystal molecules 30 are aligned perpendicularly to the substrate surface during black display, and the polarization direction of the linearly polarized light is perpendicular to the direction of the transmission axis of the polarizing plate 14b. , The light is blocked by the polarizing plate 14b. In addition, as shown in FIG. 3, during white display, the liquid crystal molecules 30 are aligned parallel to the substrate surface, and the polarization direction of linearly polarized light is influenced by the refractive index anisotropy of the liquid crystal molecules 30 and the transmission axis of the polarizing plate 14b. Therefore, the light passes through the polarizing plate 14b and is output to the front side of the panel.

  On the other hand, the light output from the backlight unit 20 becomes linearly polarized light when passing through the polarizing plate 14a on the back side of the panel, and is rotated in a certain direction by the λ / 4 plate 15a (right rotation in FIGS. 2 and 3). Is converted into circularly polarized light that passes through the transparent electrode 17b. This light is converted into linearly polarized light by the front side λ / 4 plate 15b. At this time, as shown in FIG. 2, during black display, the polarization direction of the linearly polarized light is perpendicular to the direction of the transmission axis of the polarizing plate 14b, so that the light is blocked by the polarizing plate 14b. Also, as shown in FIG. 3, during white display, the polarization direction of the linearly polarized light is parallel to the direction of the transmission axis of the polarizing plate 14b due to the influence of the refractive index anisotropy of the liquid crystal molecules 30, so that the light is polarized. Is transmitted to the front side of the panel.

  In the conventional transflective liquid crystal display device, as described above, in the transmissive region, the light emitted from the backlight unit 20 is transmitted through the transparent electrode 17b and output to the front side of the liquid crystal panel 10. However, in the reflection region, the light emitted from the backlight unit 20 is absorbed by the polarizing plate 14a and is wasted. That is, the light output from the backlight unit 20 becomes linearly polarized light when passing through the polarizing plate 14a, and is circularly polarized light that rotates in a certain direction (rotates clockwise in FIGS. 2 and 3) by the λ / 4 plate 15a. Is converted to This light is reflected by the reflective electrode 17a and becomes a circularly polarized light of reverse rotation (left rotation in FIGS. 2 and 3), and is converted into linearly polarized light by the λ / 4 plate 15a. The linearly polarized light cannot pass through the polarizing plate 14a because the polarization direction is perpendicular to the transmission axis of the polarizing plate 14a.

  In the liquid crystal display device, further power saving is demanded. However, as described above, the light output from the backlight unit 20 and reflected by the reflective electrode 17a is eventually absorbed by the polarizing plate 14a, and is wasted. If the light reflected by the reflective electrode 17a can be returned to the backlight unit 20, the light can be emitted again to the transmission region, and the light utilization efficiency is improved, which is even more than in the past. It becomes possible to save power.

  The conventional liquid crystal display device also has the following problems. That is, in the process of manufacturing the TFT substrate, defects such as disconnection or short circuit of wiring (gate bus line, data bus line, etc.) may occur. Most of these defects are found after actually forming a liquid crystal panel and laminating a polarizing plate. When there is no λ / 4 plate, wiring and the like can be observed through the polarizing plate, so that a defective portion of the TFT substrate can be detected visually. However, in the case of a liquid crystal display device in which a λ / 4 plate is disposed between the liquid crystal panel and the polarizing plate, the light reflected by the wiring or the like cannot pass through the polarizing plate, so the defect is inspected visually. I can't.

  As described above, an object of the present invention is to allow the light emitted from the backlight unit to the reflection area to be returned to the backlight unit, and to improve the light utilization efficiency compared to the conventional liquid crystal display device and its manufacture Is to provide a method.

  Another object of the present invention is a liquid crystal display device in which retardation plates and polarizing plates are respectively arranged on both sides of the liquid crystal panel, and a liquid crystal display device capable of visually inspecting defects such as bus lines and the like. It is to provide a manufacturing method.

The above-described problem includes a first substrate, a second substrate disposed to face the first substrate, and a liquid crystal sealed between the first substrate and the second substrate. A liquid crystal panel including a plurality of pixels arranged, a first λ / 4 plate disposed on a surface of the first substrate opposite to the surface on the liquid crystal layer side, and A first polarizing plate, a second λ / 4 plate and a second polarizing plate disposed on a surface opposite to the surface of the second substrate on the liquid crystal layer side, and the first polarizing plate. On the surface of the substrate on the liquid crystal layer side, a plurality of gate bus lines to which scanning signals are supplied, a plurality of data bus lines to which display signals are supplied, and provided for each pixel are driven by the scanning signals. And a pixel electrode that is provided for each pixel and to which the display signal is supplied via the switching element The first λ / 4 plate, or the first λ / 4 plate and the first polarizing plate are aligned with at least one of the gate bus line and the data bus line. An opening is provided at a position, and light reflected by at least one of the gate bus line and the data bus line passes through the opening and the first λ / 4 plate and the first polarizing plate. This is solved by a liquid crystal display device characterized by transmitting light.

  In the present invention, the first λ / 4 plate and the first polarizing plate are disposed on the surface of the first substrate opposite to the surface on the liquid crystal layer side, and these first λ / 4 plate and At least one of the first polarizing plates has an opening at a position aligned with at least one of the gate bus line and the data bus line. Thus, even after the λ / 4 plate and the polarizing plate are bonded to the liquid crystal panel, the gate bus line or the data bus line can be visually observed, and the defective portion can be easily identified.

  Further, in the case of a liquid crystal display device having a reflective electrode, an output is provided from the backlight unit by providing an opening at a position that matches the reflective electrode of either the first λ / 4 plate or the first polarizing plate. Thus, the light reflected by the reflective electrode can be returned to the backlight unit. Thereby, the utilization efficiency of light can be improved, and further power saving can be achieved as compared with the conventional case.

  The above-described problems include a step of forming a plurality of gate bus lines to which a scanning signal is supplied and a plurality of data bus lines to which a display signal is supplied on the first surface of the first substrate; A step of bonding a λ / 4 plate on the second surface of one substrate, a step of forming a photoresist film on the λ / 4 plate, and exposing the photoresist film, followed by development processing. Exposing the λ / 4 plate at a position aligned with the gate bus line and the data bus line, etching the λ / 4 plate using the photoresist film as a mask, and removing the photoresist film. This is solved by a method for manufacturing a liquid crystal display device, comprising: a step; and a step of disposing a second substrate so as to face the first substrate and enclosing a liquid crystal therebetween.

  In the present invention, after forming a gate bus line and a data bus line on one surface (first surface) of the first substrate, λ is formed on the other surface (second surface) of the first substrate. / 4 plate is joined, and an opening is formed at a position aligned with the gate bus line and data bus line of the λ / 4 plate. In the liquid crystal display device thus manufactured, the light reflected by the gate bus line and the data bus line can be visually observed even after the polarizing plate is bonded to the liquid crystal panel. As a result, it is possible to easily identify a defective portion of the gate bus line and the data bus line.

  Hereinafter, the present invention will be described with reference to the accompanying drawings.

(First embodiment)
4 is a plan view showing the liquid crystal display device according to the first embodiment of the present invention, FIG. 5 is a cross-sectional view taken along line II in FIG. 4, and FIG. 6 is a cross-sectional view taken along line II-II in FIG.

  As shown in FIGS. 5 and 6, the liquid crystal display device of this embodiment includes a liquid crystal panel 100, λ / 4 plates 141 a and 141 b and polarizing plates (linear polarizing plates) 142 a and 142 b joined to the liquid crystal panel 100. And a backlight unit (not shown). The structure of the backlight unit is basically the same as the conventional one (see FIG. 1).

  The liquid crystal panel 100 includes a TFT substrate 110 and a counter substrate 130 disposed to face each other, and a liquid crystal layer 140 made of liquid crystal having negative dielectric anisotropy enclosed between them.

  The λ / 4 plate 141a is bonded to the back side (lower side in FIGS. 5 and 6) of the liquid crystal panel 100, and a polarizing plate is placed on the λ / 4 plate 141a (lower side in FIGS. 5 and 6). 142a is joined. The λ / 4 plate 141b is bonded to the front side (the upper side in FIGS. 5 and 6) of the liquid crystal panel 100, and the polarizing plate 142b is bonded to the λ / 4 plate 141b. The polarizing plates 142a and 142b are arranged so that the absorption axes are orthogonal to each other. Further, the λ / 4 plates 141a and 141b are arranged so that their slow axes are orthogonal to each other, and the angle formed by the slow axis and the absorption axis of the adjacent polarizing plate is 45 °. In the present embodiment, as shown in FIGS. 5 and 6, the λ / 4 plate 141 a on the back side is provided with an opening 150 at a position aligned with the gate bus line 112 and the data bus line 115. .

  As shown in FIG. 4, a plurality of gate bus lines 112 extending in the horizontal direction (X-axis direction) and a plurality of data bus lines 115 extending in the vertical direction (Y-axis direction) are formed on the TFT substrate 110. Yes. The gate bus lines 112 are arranged at a constant interval (for example, about 300 μm) in the vertical direction, and the data bus lines 115 are arranged at a constant interval (for example, about 100 μm) in the horizontal direction. The width of the gate bus line 112 is, for example, 10 μm, and the width of the data bus line 115 is, for example, 7 μm. Each rectangular area defined by the gate bus line 112 and the data bus line 115 is a pixel area. Further, the auxiliary capacitance bus line 113 is formed on the TFT substrate 110 so as to be parallel to the gate bus line 112 and cross the central portion of each pixel region.

  The TFT substrate 110 includes a TFT 116, a transparent electrode 120a. 120b and 120c and the auxiliary capacitance electrode 118 are formed. Transparent electrode 120a. 120b and 120c are made of a transparent conductor such as ITO (Indium-Tin Oxide). These transparent electrodes 120a, 120b, and 120c are formed in a substantially square shape having a side of about 80 μm, for example. Each transparent electrode 120a. 120b and 120c are electrically connected to each other by a connection wiring 120d made of ITO.

  The transparent electrode 120a is electrically connected to the wiring 118a extending from the source electrode 116b of the TFT 116 through the contact hole 119a. The transparent electrode 120b is electrically connected to the auxiliary capacitance electrode 118 through the contact hole 119b.

  A scanning signal is supplied to the gate bus line 112 from a driving circuit (not shown), and a display signal is supplied to the data bus line 115 from the driving circuit. The TFT 116 is driven by the scanning signal to be turned on or off, and transmits the display signal supplied to the data bus line 115 to the pixel electrodes (transparent electrodes 120a, 120b, 120c) when being turned on.

  Hereinafter, with reference to FIGS. 5 and 6, a manufacturing method of the liquid crystal display device of the present embodiment will be described. First, a method for manufacturing the TFT substrate 110 will be described.

  First, a metal film having a laminated structure of, for example, Al (aluminum) -Ti (titanium) is formed on a glass substrate 110a serving as a base of the TFT substrate 110 by sputtering. Then, the metal film is patterned by a photolithography method to form the gate bus line 112 and the auxiliary capacitor bus line 113.

Next, a first insulating film (gate insulating film) 114 is formed by depositing SiO ₂ to a thickness of 0.3 μm on the entire upper surface of the glass substrate 110a by, eg, CVD (Chemical Vapor Deposition). Then, a semiconductor film (amorphous silicon or polysilicon film) 116 a that becomes an active layer of the TFT 116 is formed on a predetermined region of the first insulating film 114. After that, for example, a SiN film is formed on the entire upper surface of the glass substrate 110a, and this SiN film is patterned to form a channel protective film 117 on a region to be a channel of the semiconductor film 116a.

  Next, a metal film having a laminated structure of Ti—Al—Ti is formed on the entire upper surface of the glass substrate 110a, and this metal film is patterned by a photolithography method, so that the data bus line 115, the source electrode 116b, the source A wiring 118a connected to the electrode 116b, a drain electrode 116c, and an auxiliary capacitance electrode 118 are formed. The data bus line 115 is formed in connection with the drain electrode 116c as described above. The source electrode 116b is formed at a position facing the drain electrode 116c with the channel protective film 117 interposed therebetween. Further, the auxiliary capacitance electrode 118 is formed at a position facing the auxiliary capacitance bus line 113 with the first insulating film 114 interposed therebetween. The auxiliary capacitance electrode 118, the first insulating film 114, and the auxiliary capacitance bus line 113 constitute an auxiliary capacitance.

  Next, a λ / 4 plate 141a is bonded to the back side of the glass substrate 110a, and an opening 150 is formed at a position aligned with the gate bus line 112 and the data bus line 115 of the λ / 4 plate 141a. A method for forming the opening of the λ / 4 plate 141a will be described with reference to FIGS.

  First, as shown in FIG. 7A, a λ / 4 plate 141a is attached to the back side of the glass substrate 110a. As the λ / 4 plate 141a, for example, SEH-4601351 manufactured by Sumitomo Chemical Co., Ltd. can be used.

  Next, as shown in FIG. 7B, a negative photoresist is applied on the λ / 4 plate 141a (the lower side in FIG. 7B) to form a photoresist film 151. Thereafter, the photoresist film 151 is exposed from the side (the upper side in FIG. 7B) on which the gate bus line 112 and the data bus line 115 are formed, and then developed.

  As a result, as shown in FIG. 7C, the exposed portion of the photoresist film 151 remains, and the portions matching the gate bus line 112 and the data bus line 115 are removed. Thereafter, a portion of the λ / 4 plate 141a that is not covered with the photoresist film 151 is removed by a wet etching method to form an opening 150 as shown in FIG. Thereafter, the photoresist film 151 is removed.

After the λ / 4 plate 141a is bonded to the back surface side of the glass substrate 110a in this way and the opening 150 is formed, the _second upper surface of the glass substrate 110a having a thickness of 0.3 μm made of, for example, SiO ₂ is formed. An insulating film (final protective film) 119 is formed. Then, a contact hole 119a leading to the wiring 118a and a contact hole 119b leading to the auxiliary capacitance electrode 118 are formed in the second insulating film 119 by photolithography. The size of these contact holes 119a and 119b is, for example, 5 × 5 μm.

  Next, an ITO film is formed on the entire upper surface of the glass substrate 110a by sputtering. Then, this ITO film is patterned by a photolithography method to form transparent electrodes 120a, 120b, 120c and connection wirings 120d connecting them. As described above, these transparent electrodes 120a, 120b, and 120c have a substantially square shape with a side of about 80 μm, for example. The interval between the transparent electrodes 120a, 120b, 120c is, for example, 8 μm, and the width of the connection wiring 120 is, for example, 5 μm. The transparent electrode 120a is electrically connected to the wiring 118a through the contact hole 119a, and the transparent electrode 120b is electrically connected to the auxiliary capacitance electrode 118 through the contact hole 119b.

  Next, for example, polyimide is applied to the entire upper surface of the glass substrate 110a to form a vertical alignment film (not shown) that covers the surfaces of the transparent electrodes 120a, 120b, and 120c. Thereby, the TFT substrate 110 is completed.

  In this embodiment, the case where the opening 150 is formed by bonding the λ / 4 plate 141a to the back side of the glass substrate 110a after forming the gate bus line 112 and the data bus line 115 has been described. The bonding of the plate 141a and the formation of the opening 150 may be performed after the second insulating film 119 or the transparent electrodes 120a, 120b, and 120c are formed on the glass substrate 110, for example.

  Next, a method for manufacturing the counter substrate 130 will be described. First, the black matrix 132 is formed on a glass substrate 130a serving as a base of the counter substrate 130 (on the lower side in FIGS. 5 and 6) using a metal such as Cr (chrome) or a black resin. The black matrix 132 is formed slightly wider than the gate bus lines 112 and the data bus lines 115 at positions facing the gate bus lines 112, the data bus lines 115, and the TFTs 116 on the TFT substrate 110 side. In the present embodiment, the width of the black matrix 132 is formed wider by 8 μm on both sides than the gate bus line 112 and the data bus line 115. As described above, when the width of the gate bus line 112 is 10 μm and the width of the data bus line 115 is 7 μm, the width of the portion of the black matrix 132 facing the gate bus line 112 is 26 μm and facing the data bus line 115. The width of the portion to be made is 23 μm.

  Next, a color filter 133 is formed on the glass substrate 130a using a red photosensitive resin, a green photosensitive resin, and a blue photosensitive resin. In each pixel, a color filter 133 of any one of red, green, and blue is arranged. In the present embodiment, one pixel is constituted by three pixels of a red pixel, a green pixel, and a blue pixel adjacent in the horizontal direction, and various colors can be displayed.

  Next, the common electrode 134 made of ITO is formed on the color filter 133 by sputtering. After that, a photoresist is applied on the common electrode 134 to form a photoresist film, this photoresist film is exposed through a predetermined exposure mask, and then subjected to a development treatment, so that a substantially conical protrusion ( Orientation control structure) 135 is formed. These protrusions 135 are formed at positions facing the central portions of the transparent electrodes 120a, 120b, and 120c, respectively. The diameter of the bottom surface of these protrusions 135 is, for example, about 10 μm, and the height is, for example, 2.5 μm. In addition to the protrusions described above, slits and depressions provided in the electrodes can be used as the alignment control structure.

  Next, for example, polyimide is applied to the entire upper surface of the glass substrate 130 a to form a vertical alignment film (not shown) that covers the surfaces of the common electrode 134 and the protrusions 135. Thereby, the counter substrate 130 is completed.

  The TFT substrate 110 and the counter substrate 130 manufactured in this way are arranged so as to face each other with a spacer (not shown) interposed therebetween, and a liquid crystal having a negative dielectric anisotropy is sealed between them. The liquid crystal panel 100 is assumed. Then, a polarizing plate 142a is bonded on the λ / 4 plate 141a on the back side of the liquid crystal panel 100 (lower side in FIGS. 5 and 6), and the λ / 4 plate on the front side (upper side in FIGS. 5 and 6). 141b and the polarizing plate 142b are joined. A backlight unit is attached to the back side of the liquid crystal panel 100.

  In the liquid crystal display device of the present embodiment thus manufactured, the transparent electrodes 120a. When a voltage is applied between 120b, 120c and the common electrode 134, the liquid crystal molecules in the liquid crystal layer 140 are inclined at an angle corresponding to the applied voltage. In the liquid crystal display device of this embodiment, when viewed from the front side of the panel, the liquid crystal molecules are aligned radially around the protrusions 135.

  The light emitted from the backlight unit becomes linearly polarized light when passing through the polarizing plate 142a on the back side, and is converted into circularly polarized light by the λ / 4 plate 141a. This circularly polarized light is transmitted through the transparent electrodes 120a. The light passes through 120b and 120c, and further passes through the liquid crystal layer 140 to reach the λ / 4 plate 141b on the front surface side. The λ / 4 plate 141b converts the light into linearly polarized light, and an amount of light corresponding to the tilt angle of the liquid crystal molecules passes through the polarizing plate 142b and is output to the front side of the panel.

  In the present embodiment, the λ / 4 plate 141 a on the back surface side is provided with an opening 150 at a position facing the gate bus line 112 and the data bus line 115. Therefore, the light transmitted through the polarizing plate 142a from the back side and reflected by the gate bus line 112, the data bus line 115, and the like passes through the polarizing plate 142a. Thereby, even after the λ / 4 plate 141a and the polarizing plate 142a are bonded to the liquid crystal panel 100, the inspection of the defects such as the gate bus line 112 and the data bus line 115 can be visually performed, and the defective portion is identified. Can be easily identified.

  In the above-described embodiment, the case where the present invention is applied to a transmissive liquid crystal display device is described. However, the present invention can also be applied to a transflective liquid crystal display device and a reflective liquid crystal display device.

  In the above-described embodiment, the opening 150 is formed in the λ / 4 plate 141a on the back side. However, the opening is formed at a position matching the gate bus line 112 and the data bus line 115 of the polarizing plate 142a on the back side. Even if it forms, the same effect can be acquired.

(Second Embodiment)
FIG. 8 is a plan view showing a liquid crystal display device according to a second embodiment of the present invention, and FIG. 9 is a sectional view taken along line III-III in FIG. This embodiment shows an example in which the present invention is applied to a transflective liquid crystal display device.

  As shown in FIG. 9, the liquid crystal display device of this embodiment includes a liquid crystal panel 200, λ / 4 plates 241a and 241b and polarizing plates (linear polarizing plates) 242a and 242b joined to the liquid crystal panel 200, and a liquid crystal panel. And a backlight unit (not shown) disposed on the back surface side of 200 (lower side in FIG. 9). The structure of the backlight unit is basically the same as the conventional one (see FIG. 1).

  The liquid crystal panel 200 includes a TFT substrate 210 and a counter substrate 130 disposed to face each other, and a liquid crystal layer 140 made of liquid crystal having negative dielectric anisotropy enclosed between them.

  As shown in FIG. 8, a plurality of gate bus lines 212 extending in the horizontal direction (X-axis direction) and a plurality of data bus lines 215 extending in the vertical direction (Y-axis direction) are formed on the TFT substrate 210. Yes. The gate bus lines 212 are arranged at regular intervals (for example, 300 μm) in the vertical direction, and the data bus lines 215 are arranged at regular intervals (for example, 100 μm) in the horizontal direction. Each rectangular area defined by the gate bus line 212 and the data bus line 215 is a pixel area. Further, the auxiliary capacitance bus line 213 is formed on the TFT substrate 210 so as to be parallel to the gate bus line 212 and cross the central portion of each pixel region.

  The TFT substrate 210 is provided with a TFT 216, an auxiliary capacitance electrode 218, a reflective electrode 220, and transparent electrodes 222a, 222b, and 222c for each pixel. The TFT 216 uses a part of the gate bus line 212 as a gate electrode, and a source electrode 216b and a drain electrode 216c are arranged on both sides of the gate electrode in the Y-axis direction.

  One pixel region is divided into three regions arranged along the data bus line 215. Hereinafter, the central region of these three regions is referred to as a reflection region B, and two regions sandwiching the reflection region B are referred to as a first transmission region A1 and a second transmission region A2.

  A transparent electrode 222a is disposed in the first transmission region A1, a transparent electrode 222b is disposed in the reflection region B, and a transparent electrode 222c is disposed in the second transparent electrode A2. These transparent electrodes 222a, 222b, and 222c are all formed of a transparent conductor such as ITO, and are electrically connected to each other via a connection wiring 222d that is made of a transparent conductor formed simultaneously with the transparent electrodes 222a, 222b, and 222c. It is connected. The transparent electrode 222a is electrically connected to the wiring 218a extending from the source electrode 216b through the contact hole 219a.

  A substantially rectangular reflective electrode 220 is formed below the transparent electrode 222b in the reflective region B. The surface of the reflective electrode 220 is made of a metal having high reflectivity such as Al. Further, an auxiliary capacitance electrode 218 is formed below the reflective electrode 220. The reflective electrode 220 is electrically connected to the auxiliary capacitance electrode 218 through the contact hole 218b.

  Similar to the first embodiment, a black matrix 132, a color filter 133, a common electrode 134, an alignment control protrusion 135, and the like are formed on the counter substrate 130.

  A λ / 4 plate 241a is bonded to the back side (lower side in FIG. 9) of the liquid crystal panel 200, and a polarizing plate 242a is bonded to the λ / 4 plate 241a (lower side in FIG. 9). Yes. Further, a λ / 4 plate 241b is bonded to the front side of the liquid crystal panel 200 (upper side in FIG. 9), and a polarizing plate 242b is bonded to the λ / 4 plate 241b. The polarizing plates 242a and 242b are arranged so that their absorption axes are orthogonal to each other. The λ / 4 plates 241a and 241b are arranged so that their slow axes are orthogonal to each other and the angle formed by the slow axis and the absorption axis of the adjacent polarizing plate is 45 °.

  In the present embodiment, as shown in FIG. 9, the λ / 4 plate 241a on the back side is provided with an opening 250 at a position facing the gate bus line 212, the data bus line 215, and the reflective electrode 220. Yes.

  Also in this embodiment, a scanning signal is supplied to the gate bus line 212 from a driving circuit (not shown), and a display signal is supplied to the data bus line 215 from the driving circuit. The TFT 216 is driven by a scanning signal, and transmits a display signal to the pixel electrodes (transparent electrodes 222a, 222b, 222c and the reflective electrode 220) when the TFT 216 is turned on.

  Hereinafter, a method for manufacturing the liquid crystal display device of the present embodiment will be described with reference to FIGS. Note that the manufacturing method of the counter substrate 130 is basically the same as that of the first embodiment, and the description thereof is omitted here.

  First, a metal film having an Al—Ti laminated structure is formed on a glass substrate 210 a serving as a base of the TFT substrate 210 by, eg, sputtering. Then, the metal film is patterned by a photolithography method to form the gate bus line 212 and the auxiliary capacitor bus line 213.

Next, a first insulating film (gate insulating film) 214 is formed by depositing SiO ₂ to a thickness of 0.3 μm on the entire upper surface of the glass substrate 210a by, eg, CVD. Then, a semiconductor film (amorphous silicon or polysilicon film) serving as an active layer of the TFT 216 is formed on a predetermined region of the first insulating film 214. Thereafter, for example, a SiN film is formed on the entire upper surface of the glass substrate 210a, and this SiN film is patterned to form a channel protective film on a region to be a channel of the semiconductor film.

  Next, a metal film having a laminated structure of Ti—Al—Ti is formed on the entire upper surface of the glass substrate 210a, and this metal film is patterned by a photolithography method to form a data bus line 215, a source electrode 216b, a source A wiring 218a connected to the electrode 216b, a drain electrode 216c, and an auxiliary capacitance electrode 218 are formed. The auxiliary capacitance electrode 218 is formed at a position facing the auxiliary capacitance bus line 213 with the first insulating film 214 interposed therebetween. The auxiliary capacitance electrode 218, the first insulating film 214, and the auxiliary capacitance bus line 213 constitute an auxiliary capacitance.

Next, a second insulating film 219 made of, for example, SiO ₂ and having a thickness of 0.3 μm is formed on the entire upper surface of the glass substrate 210a. Then, a contact hole 219b leading to the auxiliary capacitance electrode 218 is formed in the second insulating film 219 by photolithography.

  Next, a metal film having a laminated structure of, for example, Ti—Al—Ti is formed on the entire upper surface of the glass substrate 210a, and the reflective film 220 is formed by patterning the metal film. The reflective electrode 220 has, for example, a substantially square shape with a side of about 80 μm. The reflective electrode 220 is electrically connected to the auxiliary capacitance electrode 218 through the contact hole 219b.

  Next, a λ / 4 plate 241a is bonded to the back surface side of the glass substrate 210a, and an opening 250 is formed at a position aligned with the gate bus line 212, the data bus line 215, and the reflective electrode 220 of the λ / 4 plate 241a. . A method for forming the opening 250 of the λ / 4 plate 214a will be described with reference to FIGS.

  First, as shown in FIG. 10A, a λ / 4 plate 241a is bonded to the back side of the glass substrate 210a. As the λ / 4 plate 241a, for example, SEH-4601351 manufactured by Sumitomo Chemical Co., Ltd. can be used.

  Next, as shown in FIG. 10B, a negative photoresist is applied on the λ / 4 plate 241a (lower side in FIG. 11B) to form a photoresist film 251. Thereafter, the photoresist film 251 is exposed from the surface side (the upper side in FIG. 10B) on which the gate bus line 212 and the data bus line 215 are formed, and then developed.

  As a result, as shown in FIG. 10C, the exposed portion of the photoresist film 251 remains, and the portions matching the gate bus line 212, the data bus line 215, and the reflective electrode 220 are removed, and the photoresist film is removed. An opening 251a of 251 is formed. Thereafter, a portion of the λ / 4 plate 241a that is not covered with the photoresist film 251 is removed by wet etching to form an opening 250 of the λ / 4 plate 241a as shown in FIG. . Thereafter, the photoresist film 251 is removed.

After the λ / 4 plate 214a is bonded to the back side of the glass substrate 210a and the opening 250 is formed in this way, the entire upper surface of the glass substrate 210a is made of, for example, SiO ₂ as shown in FIG. A third insulating film 221 having a thickness of 0.3 μm is formed. Then, by photolithography, an opening for exposing the reflective electrode 220 is formed in the third insulating film 221 as shown in FIG. 11B, and a contact hole 219a leading to the wiring 218a is formed. In this photolithography process, the uppermost Ti layer of the reflective electrode 220 is removed to expose the Al layer.

  Next, an ITO film is formed on the entire upper surface of the glass substrate 210a by sputtering. Then, this ITO film is patterned by a photolithography method to form transparent electrodes 222a, 222b, 222c and connection wirings 222d that connect them as shown in FIG. 11C. The transparent electrode 222a is connected to the wiring 218a through the contact hole 219a, and the transparent electrode 222b is connected to the reflective electrode 220 through the opening of the third insulating film 221.

  Next, for example, polyimide is applied to the entire upper surface of the glass substrate 210a to form a vertical alignment film (not shown) that covers the surfaces of the transparent electrodes 222a, 222b, and 222c. Thereby, the TFT substrate 210 is completed.

  In the present embodiment, the case where the opening 250 is formed by bonding the λ / 4 plate 214a to the back side of the glass substrate 210a after forming the gate bus line 212, the data bus line 215, and the reflective electrode 220 has been described. However, the bonding of the λ / 4 plate 214a and the formation of the opening 250 may be performed after the third insulating film 221 or the transparent electrodes 22a, 222b, and 222c are formed on the glass substrate 210a, for example.

  The TFT substrate 210 and the counter substrate 130 manufactured in this way are arranged to face each other with a spacer (not shown) interposed therebetween, and a liquid crystal having a negative dielectric anisotropy is sealed between them. The liquid crystal panel 200 is assumed. Then, a polarizing plate 242a is bonded onto the λ / 4 plate 241a on the back side of the liquid crystal panel 210 (lower side in FIG. 9), and the λ / 4 plate 241b and the polarizing plate 242b are connected to the front side (upper side in FIG. 9). Join.

  In the liquid crystal display device of this embodiment, when a voltage is applied between the transparent electrodes 222a, 222b, 222c and the common electrode 134, the liquid crystal molecules in the liquid crystal layer 140 are inclined at an angle corresponding to the applied voltage. In the present embodiment, when viewed from the front side of the panel, the liquid crystal molecules are aligned radially around the protrusions (alignment control structures) 135.

  The light transmitted through the polarizing plate 242b and the λ / 4 plate 241b from the front side of the liquid crystal panel 200 (upper side in FIG. 9) further passes through the common electrode 134 and enters the liquid crystal layer 140. This light is reflected by the reflective electrode 220 disposed in the reflective region B, passes through the common electrode 134, the λ / 4 plate 242b, and the polarizing plate 242b, and is output to the front side of the panel. However, when the light passes through the polarizing plate 242b, an amount of light corresponding to the tilt angle of the liquid crystal molecules is blocked by the polarizing plate 242b.

  On the other hand, the light output from the backlight unit is transmitted through the polarizing plate 242a and the λ / 4 plate 241a on the back surface side (lower side in FIG. 9) of the liquid crystal panel 200, and further transmitted through the transparent electrodes 222a and 222c. Enter the layer 140. The light passes through the common electrode 134, the λ / 4 plate 241b, and the polarizing plate 242b and is output to the front side of the panel. However, in the transmissive regions A1 and A2, as in the reflective region B, an amount of light corresponding to the tilt angle of the liquid crystal molecules is absorbed by the polarizing plate 242b when passing through the polarizing plate 242b.

  FIG. 12 is a schematic diagram showing a light state during black display of the transflective liquid crystal display device of the present embodiment. In FIG. 12, 20 indicates a backlight unit, and 30 indicates liquid crystal molecules in the liquid crystal layer. In addition, the light enters the liquid crystal layer from the front side of the panel (upper side in FIG. 12), is reflected by the reflective electrode 220 and is directed toward the front side of the panel, and is output from the backlight unit 20. Since the behavior of the light transmitted through the front side of the panel is as described with reference to FIG. 2, the description thereof is omitted here.

  As shown in FIG. 12, the light output from the backlight unit 20 becomes linearly polarized light when passing through the polarizing plate 242a on the back side of the panel. In this embodiment, since there is no λ / 4 plate between the polarizing plate 242a and the reflective electrode 220, the light transmitted through the polarizing plate 242a and reflected by the reflective electrode 220 has a polarization direction of the transmission axis of the polarizing plate 242a. Since it is parallel to the direction, it passes through the polarizing plate 242a again and enters the light guide plate of the backlight unit 20. Then, this light is scattered and reflected by the light guide plate, and finally emitted to the transmission region.

  In the liquid crystal display device of the present embodiment, as in the first embodiment, the λ / 4 plate 241a on the back side is provided with an opening 250 at a position facing the gate bus line 212 and the data bus line 215. ing. Therefore, the light transmitted through the polarizing plate 242a from the back side and reflected by the gate bus line 212, the data bus line 215, and the like passes through the polarizing plate 242a. Thereby, even after the λ / 4 plate 241a and the polarizing plate 242a are bonded to the liquid crystal panel 200, the inspection of defects such as the gate bus line 212 and the data bus line 215 can be performed by visual inspection. Can be easily identified.

  The λ / 4 plate 241 a is also provided with an opening 250 at a position facing the reflective electrode 220. Therefore, the light output from the backlight unit and reflected by the reflective electrode 220 is incident on the backlight unit. Thereby, the utilization efficiency of light can be improved, and further power saving can be achieved as compared with the conventional case.

  In the above embodiment, the third insulating film 221 is formed on the data bus line 215, the source electrode 216b, the drain electrode 216c, and the auxiliary capacitance electrode 218, and then the reflective electrode 220 is formed. 220 and the auxiliary capacitance electrode 218 may be integrated and formed simultaneously with the data bus line 215, the source electrode 216b, and the drain electrode 216c.

  That is, after forming the second metal film, the metal film is patterned to form the data bus line 215, the source electrode 216b, the drain electrode 216c, and the reflective electrode 220. Thereafter, a final protective film is formed on the entire upper surface of the glass substrate 210a, and an opening is provided at a position that matches the reflective electrode 220 of the final protective film. Next, an ITO film is formed on the entire upper surface of the glass substrate 210a, and the ITO film is patterned to form transparent electrodes 222a, 222b, and 222c. By forming the TFT substrate in this way, the number of manufacturing steps can be reduced.

(Third embodiment)
FIG. 13 is a plan view showing a liquid crystal display device according to a third embodiment of the present invention, and FIG. 14 is a sectional view taken along line IV-IV in FIG. Note that this embodiment is different from the second embodiment in that a λ / 4 plate is provided on the surface of the TFT substrate on the liquid crystal layer side, and the other structure is basically the second embodiment. The description of the overlapping parts is omitted.

  In the liquid crystal display device of the present embodiment, as shown in FIG. 14, a polarizing plate 242a is bonded to the back side (lower side in FIG. 14) of the liquid crystal panel 200, and the front side (in FIG. 14). The λ / 4 plate 241b and the polarizing plate 242b are joined to the upper side. Further, a λ / 4 plate 252 is formed on the TFT substrate 210 instead of the third insulating film 221 of the second embodiment.

  15 and 16 are cross-sectional views showing the method of manufacturing the TFT substrate 210 of the liquid crystal display device of this embodiment in the order of steps. In FIG. 15 and FIG. 16, illustration of the auxiliary capacity bus line, the auxiliary capacity electrode, and the like is omitted.

  First, as shown in FIG. 15A, a gate bus line 212, an auxiliary capacitance bus line 213, a first insulating film 214, a data bus line 215, and an auxiliary circuit are formed on a glass substrate 210a serving as a base of the TFT substrate 210. A capacitor electrode 218, a TFT 216, a second insulating film 219, and a reflective electrode 220 are formed. The reflective electrode 220 is formed in an approximately square shape having a side of about 80 μm, for example, by an Al film having a thickness of 0.1 μm.

  Next, as shown in FIG. 15B, a λ / 4 plate 252 is attached to the upper side of the glass substrate 210a. As the λ / 4 plate 252, for example, SEH-4601351 manufactured by Sumitomo Chemical Co., Ltd. can be used.

  Next, as shown in FIG. 15C, a positive photoresist is applied on the λ / 4 plate 252 to form a resist film 253. Thereafter, the resist film 253 is exposed through a predetermined exposure mask and then developed to provide an opening 253a of the resist film 253 at a position aligned with the reflective electrode 220 as shown in FIG. . However, at this time, it is preferable to form the opening 253a slightly smaller than the reflective electrode 220. Further, after applying a negative photoresist on the λ / 4 plate 252, the resist film may be exposed from the lower side of the glass substrate 210a. In this case, an opening is also formed at a position aligned with the gate bus line 212 and the data bus line 215.

  Next, the λ / 4 plate 252 is wet-etched or dry-etched using the resist film 253 as an etching mask to expose the reflective electrode 220 as shown in FIG. At the same time, a contact hole 219a leading from the surface of the λ / 4 plate 252 to the wiring 218a connected to the source electrode 216b is formed. Thereafter, the resist film 253 is removed.

  Next, as shown in FIG. 16C, ITO is sputtered on the entire upper surface of the glass substrate 210 to form an ITO film, and this ITO film is patterned by a photolithography method to obtain transparent electrodes 222a, 222b, 222c, and A connection electrode 222d is formed. Thereafter, polyimide is applied to the entire upper surface of the glass substrate 210a to form a vertical alignment film that covers the surfaces of the transparent electrodes 222a, 222b, and 222c and the connection wiring 222d. In this way, the TFT substrate of the liquid crystal display device of this embodiment is completed.

  In the liquid crystal display device of this embodiment, there is no λ / 4 plate between the polarizing plate 242a disposed on the back surface side and the gate bus line 212, the data bus line 215, and the reflective electrode 220, so the second embodiment Similarly, even after the polarizing plate 242a is bonded to the liquid crystal panel 200, defects such as the gate bus line 212 and the data bus line 215 can be visually inspected, and the defective portion can be easily identified. it can. The light output from the backlight unit and reflected by the reflective electrode 220 returns to the backlight unit. Thereby, the utilization efficiency of light can be improved, and further power saving can be achieved as compared with the conventional case.

  As shown in FIG. 17, the edges of the transparent electrodes 222a and 222c may overlap the gate bus line 212. As shown in FIG. 18, the edges of the transparent electrodes 222a, 222b and 222c are data. You may make it overlap with the bus line 215.

In order to obtain a bright screen by increasing the aperture ratio of the pixels, it is conceivable to reduce the distance between the transparent electrode, the gate bus line, and the data bus line. However, in the conventional liquid crystal display device, since the insulating film (SiO ₂ film or SiN film) between the transparent electrode and the gate bus line and the data bus line is thin, the transparent electrode and the gate bus line or the data bus line When the interval between the two is reduced, there is a problem that crosstalk occurs and display quality deteriorates. However, in the present embodiment, a λ / 4 plate 252 that is sufficiently thicker than the SiO ₂ film or the SiN film is disposed between the transparent electrodes 222a, 222b, and 222c and the gate bus line 212 and the data bus line 215. Therefore, even if the edges of the transparent electrodes 222a, 222b, and 222c are arranged so as to overlap the gate bus line 212 or the data bus line 215 as shown in FIGS. 17 and 18, the display quality is deteriorated due to crosstalk. It can be avoided.

(Fourth embodiment)
FIG. 19 is a cross-sectional view showing a liquid crystal display device according to a fourth embodiment of the present invention. In FIG. 19, the same components as those in FIG.

  This embodiment is different from the first embodiment shown in FIGS. 4 to 6 in that the λ / 4 plate 141a and the polarizing plate 142a arranged on the back side are aligned with the gate bus line 112 and the data bus line 115. Are provided with openings 150 and 160, respectively.

  In the present embodiment, as described above, since the opening 160 is also provided at a position aligned with the gate bus line 212 and the data bus line 215 of the polarizing plate 142a, the opening 160 is provided on the back side as compared with the first embodiment. The amount of reflected light is large. For this reason, in this embodiment, in addition to the same effects as those of the first embodiment, the gate bus line 212 and the data bus line 215 can be easily inspected.

(Fifth embodiment)
FIG. 20 is a cross-sectional view showing a liquid crystal display device according to a fifth embodiment of the present invention. In FIG. 20, the same components as those in FIG.

  This embodiment is different from the second embodiment shown in FIGS. 8 and 9 in that, as shown in FIG. 20, a λ / 4 plate 241a and a gate bus line 212 of a polarizing plate 242a arranged on the back surface side, The openings 250 and 260 are provided at positions matching the data bus line 215 and the reflective electrode 220, respectively, and the other structures are basically the same as those of the second embodiment. The description of the parts to be omitted is omitted.

  FIG. 21 is a schematic diagram showing the state of light during black display of the transflective liquid crystal display device of the present embodiment. In FIG. 21, 20 represents a backlight unit, and 30 represents liquid crystal molecules in the liquid crystal layer. Further, the light enters the liquid crystal layer from the front side of the panel (upper side in FIG. 21), is reflected by the reflective electrode, and is reflected from the front side of the panel, and is output from the backlight unit 20 and transmitted through the transparent electrodes 222a and 222c. Since the behavior of light toward the front side of the panel is as described with reference to FIG. 2, the description thereof is omitted here.

  As shown in FIG. 21, the light output from the backlight unit 20 travels through the opening 260 of the polarizing plate 242a and the opening 250 of the λ / 4 plate 241a, is reflected by the reflective electrode 220, and is again polarizing plate. The light enters the light guide plate of the backlight unit 20 through the opening 260 of 242a and the opening 250 of the λ / 4 plate 241a. Then, this light is scattered and reflected by the light guide plate and finally emitted to the transmission region.

  In the present embodiment, as described above, the opening 260 is also provided in the portion of the polarizing plate 242a facing the gate bus line 212 and the data bus line 115, so that it is on the back side as compared with the first embodiment. The amount of reflected light is large. Thereby, in this embodiment, in addition to the effect similar to 2nd Embodiment, there exists an effect that the utilization efficiency of light improves further.

  The manufacturing method of the liquid crystal display device of this embodiment is substantially the same as the manufacturing method of the liquid crystal display device of the second embodiment shown in FIGS. 10 and 11, and a λ / 4 plate 241a is formed on the back side of the glass substrate 210a. The polarizing plate 242a is pasted, and the openings 250 and 260 are formed at positions matching the λ / 4 plate 241a and the gate bus line 212, the data bus line 215, and the reflective electrode 220 of the polarizing plate 242a by photolithography. Is done.

(Sixth embodiment)
FIG. 22 is a cross-sectional view showing a liquid crystal display device according to a sixth embodiment of the present invention. In FIG. 22, the same components as those in FIG.

  This embodiment is different from the third embodiment shown in FIGS. 13 and 14 in that a λ / 4 plate 252 and a polarizing plate 261 are arranged on the surface of the TFT substrate 210 on the liquid crystal layer side, and the other structure. Is basically the same as that of the third embodiment, and therefore, the description of the overlapping parts is omitted here.

  In the present embodiment, a polarizing plate 261 and a λ / 4 plate 252 are stacked on the second insulating film 219, and the transparent electrodes 222 a and 222 c are formed on the λ / 4 plate 252. Further, the polarizing plate 261 and the λ / 4 plate 252 are provided with an opening at a position matching the reflective electrode 220, and the transparent electrode 222b is formed to cover the reflective electrode 220 exposed in the opening. ing.

  In the liquid crystal display device of the present embodiment, since there is no polarizing plate between the backlight unit (not shown), the gate bus line 212 and the data bus line (not shown), the back surface as compared with the third embodiment. The amount of light reflected to the side is large. For this reason, the liquid crystal display device according to the present embodiment can more easily inspect defects such as gate bus lines and data bus lines than the liquid crystal display device according to the third embodiment. In addition, since the liquid crystal display device according to the present embodiment has a large amount of light that is reflected by the reflective electrode 220 and returns to the backlight unit, the light use efficiency is further improved as compared with the liquid crystal display device according to the third embodiment. To do.

  The manufacturing method of the liquid crystal display device of this embodiment is almost the same as the manufacturing method of the liquid crystal display device of the third embodiment, and after the second insulating film 219 and the reflective electrode 220 are formed on the glass substrate 210a. The polarizing plate 261 and the λ / 4 plate 252 are joined in order, and an opening is formed at a position aligned with the reflective electrode 220 of the polarizing plate 261 and the λ / 4 plate 252 by photolithography.

  As shown in FIG. 23, the edges of the transparent electrodes 222a and 222c may overlap the gate bus line 212, and the edges of the transparent electrodes 222a, 222b and 222c as shown in FIG. The line 215 may be overlapped. In the present embodiment, the relatively thick polarizing plate 261 and λ / 4 plate 252 are interposed between the gate bus line 212 and the data bus line 215 and the transparent electrodes 222a, 222b, and 222c. 23, even if the transparent electrodes 222a, 222b, and 222c are arranged so as to overlap the gate bus line 212 and the data bus line 215 as shown in FIG. 24, display quality deterioration due to crosstalk is avoided. Also, as shown in FIGS. 23 and 24, the transparent electrodes 222a, 222b, and 222c are arranged so as to overlap the gate bus line 212 and the data bus line 215, thereby improving the aperture ratio and displaying an image brighter. be able to.

(Seventh embodiment)
FIG. 25 is a sectional view showing a liquid crystal display device according to a seventh embodiment of the present invention. 25, the same components as those in FIG. 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The liquid crystal panel 200 includes a TFT substrate 210, a counter substrate 130, and a liquid crystal layer 140 made of liquid crystal having negative dielectric anisotropy sealed between them. In the TFT substrate 210, gate bus lines, data bus lines, TFTs, and the like are formed as in the other embodiments. However, in this embodiment, a transparent resin film 270 is formed on the first insulating film 214 of the TFT substrate 210. The surface of the reflective region of the transparent resin film 270 is provided with irregularities.

  A λ / 4 plate 271 is formed on the transparent resin film 270. The λ / 4 plate 271 is provided with an opening at a position matching the reflective region. Transparent electrodes 222a and 222c are formed on the λ / 4 plate 271 in the transparent region. In the reflection region, a transparent electrode 222 b is formed on the unevenness of the transparent resin film 270 exposed at the opening of the λ / 4 plate 271. These transparent electrodes 222a, 222b, and 222c are made of a transparent conductor such as ITO, as in the second embodiment shown in FIGS. 8 and 9, and are electrically connected to each other via connection wiring. .

  The transparent electrode 222a is connected to a wiring extending from the source electrode of the TFT through a contact hole, and the transparent electrode 222b is connected to the auxiliary capacitance electrode through the contact hole.

  On the transparent electrode 222b in the reflective region, a reflective electrode 220 whose surface is made of a metal having a high reflectance such as Al is formed. On the surface of the reflective electrode 220, irregularities that follow the irregularities of the resin film 270 therebelow are formed.

  A polarizing plate 242a is disposed on the back side (lower side in FIG. 25) of the liquid crystal panel 200, and a λ / 4 plate 241b and a polarizing plate 242b are disposed on the front side (upper side in FIG. 25). The polarizing plates 242a and 242b are arranged with their absorption axes orthogonal to each other, the λ / 4 plates 271 and 241b have their slow axes orthogonal to each other, and the angle formed between the absorption axis and the slow axis of the adjacent polarizing plates Is arranged to be 45 °.

  Hereinafter, a method for manufacturing the liquid crystal display device of the present embodiment will be described. Note that the manufacturing method of the counter substrate is the same as that of the second embodiment, and thus the description thereof is omitted here.

  First, a gate bus line 212, an auxiliary capacitor bus line 213, a first insulating film 214, a TFT, a data bus line, an auxiliary capacitor are formed on a glass substrate serving as a base of the TFT substrate 210 in the same manner as in the first embodiment. An electrode 218 is formed. Thereafter, a transparent resin is applied to a thickness of about 2.0 μm on the glass substrate 210 a to form a transparent resin film 270. Then, the portion of the reflective region of the transparent resin film 270 is etched to form irregularities. In addition, a contact hole that leads to the wiring extending from the source electrode and a contact hole that leads to the auxiliary capacitance electrode 218 are formed in the transparent resin film 270. The size of the contact hole is, for example, 10 × 10 μm. In this embodiment, the unevenness is formed only on the reflective region, but the unevenness may be formed on the entire surface of the transparent resin film 270.

  Next, a λ / 4 plate 271 is attached on the transparent resin film 270. Then, after forming a positive photoresist film on the λ / 4 plate 271, the resist film in the reflective region is selectively exposed through an exposure mask. Thereafter, development processing is performed to open the resist film, and then wet etching or dry etching is performed to form an opening in the λ / 4 plate 271 to expose the transparent resin film 270 in the reflective region.

  Next, an ITO film is formed on the entire upper surface of the glass substrate 210a by sputtering, and this ITO film is patterned by photolithography to form transparent electrodes 222a, 222b, 222c and connection wirings connecting them. . In this case, irregularities that follow the surface of the transparent resin film 270 are formed on the surface of the transparent electrode 222b.

  Next, an Al film having a thickness of, for example, 0.1 μm is formed on the entire upper surface of the glass substrate 210a, and this Al film is patterned by a photolithography method to form the reflective electrode 220. On the surface of the reflective electrode 220, irregularities that follow the surface of the transparent electrode 222b are formed. Thereafter, an alignment film is formed by applying polyimide or the like on the entire upper surface of the glass substrate 210a.

  The TFT substrate 210 and the counter substrate 130 formed in this way are arranged to face each other with a spacer interposed therebetween, and a liquid crystal having a negative dielectric anisotropy is sealed between them to form a liquid crystal panel 200. Then, a polarizing plate 242a is attached to the back side of the liquid crystal panel 200, and a λ / 4 plate 241b and a polarizing plate 242b are attached to the front side. A backlight unit is attached to the back side of the liquid crystal panel 200. In this way, the liquid crystal display device of this embodiment is completed.

  In the present embodiment, in addition to the same effects as those of the second embodiment, since the surface of the reflective electrode 220 is provided with irregularities, the viewing angle characteristics when used as a reflective liquid crystal display device Has the effect of being good.

(Eighth embodiment)
FIG. 26 is a sectional view showing a liquid crystal display device according to an eighth embodiment of the present invention.

  As shown in FIG. 26, the liquid crystal display device of the present embodiment includes a liquid crystal panel 300, a polarizing plate 341a bonded to the back side (lower side in FIG. 26) of the liquid crystal panel 300, and the front side ( 26, the polarizing plate 341b bonded to the upper side) and a backlight unit (not shown) disposed on the back side of the liquid crystal panel 300.

  The liquid crystal panel 300 includes a TFT substrate 310 and a counter substrate 330 arranged to face each other, and a liquid crystal layer 340 made of liquid crystal having negative dielectric anisotropy enclosed between them. In the present embodiment, the TFT substrate 310 is disposed on the front side (observer side), and the counter substrate 330 is disposed on the back side (backlight unit side).

  As in the first embodiment, a gate bus line 312, a data bus line (not shown), a TFT (not shown), transparent electrodes 322a, 322b, and 322c are formed on the TFT substrate 310. A λ / 4 plate 320 is disposed on the surface of the TFT substrate 310 on the liquid crystal layer side.

  On the other hand, a black matrix 332, a color filter 333, a reflective film 334, and a common electrode 336 are formed on the counter substrate 330. As shown in FIG. 26, the surface of the color filter 333 that matches the reflective region has irregularities on its surface, and a reflective film 334 made of a metal having a high reflectance such as Al is formed on the irregular surface. Has been. A λ / 4 plate 335 is disposed on the color filter 333. The λ / 4 plate 335 has an opening that matches the reflective film 334. The common electrode 336 is formed so as to cover the reflective film 334 and the λ / 4 plate 335.

  Hereinafter, a method for manufacturing the liquid crystal display device of the present embodiment will be described. First, a manufacturing method of the TFT substrate 310 will be described.

  First, a metal film having an Al—Ti laminated structure is formed on the glass substrate 310a serving as a base of the TFT substrate 310 (on the lower side in FIG. 26) by, for example, sputtering. Then, the metal film is patterned by a photolithography method to form the gate bus line 312 and the auxiliary capacitor bus line 313.

Next, a first insulating film (gate insulating film) 314 is formed by depositing SiO ₂ to a thickness of 0.3 μm on the entire upper surface of the glass substrate 310a by, eg, CVD. Then, a semiconductor film serving as an active layer of the TFT is formed on a predetermined region of the first insulating film 314. Thereafter, for example, a SiN film is formed on the entire upper surface of the glass substrate 310a, and this SiN film is patterned to form a channel protective film on a region to be a channel of the semiconductor film.

  Next, a metal film having a laminated structure of, for example, Ti—Al—Ti is formed on the entire upper surface of the glass substrate 310a, and this metal film is patterned by a photolithography method, and the data bus line is formed as in the other embodiments. A source electrode, a wiring connected to the source electrode, a drain electrode, and an auxiliary capacitance electrode 318 are formed.

Next, a second insulating film 319 made of, for example, SiO ₂ and having a thickness of 0.3 μm is formed on the entire upper surface of the glass substrate 310a. Then, a λ / 4 plate 320 is bonded on the second insulating film 319. As the λ / 4 plate 320, for example, SEH-4601351 manufactured by Sumitomo Chemical Co., Ltd. can be used. Thereafter, a contact hole that leads from the surface of the λ / 4 plate 320 to the wiring connected to the source electrode and a contact hole that leads to the auxiliary capacitance electrode 318 are formed.

  Next, an ITO film is formed on the entire upper surface of the glass substrate 310a by sputtering. Then, this ITO film is patterned by a photolithography method to form transparent electrodes 332a, 332b, and 332c and connection electrodes connected between them. The shapes of these transparent electrodes 332a, 332b, and 332c are the same as in the other embodiments.

  Next, for example, polyimide is applied to the entire upper surface of the glass substrate 310a to form a vertical alignment film (not shown) that covers the surfaces of the transparent electrodes 332a, 332b, and 332c. Thereby, the TFT substrate 310 is completed.

  Next, a method for manufacturing the counter substrate 330 will be described. First, the black matrix 332 is formed of a metal such as Cr or a black resin on the glass substrate 330a serving as the base of the counter substrate 330.

  Next, a red photosensitive resin, a green photosensitive resin, and a blue photosensitive resin are used, and a color filter 333 of any one of red, green, and blue is formed in each pixel region of the glass substrate 330a by a photoresist method. Concavities and convexities are formed on the surface of the color filter 333 that matches the reflective region. The thickness of the color filter 333 is, for example, 1.0 μm.

  Next, an Al film having a thickness of, for example, 0.1 μm is formed on the entire upper surface of the glass substrate 330a by sputtering, and the Al film is patterned by photolithography to reflect on the color filter 333 in the reflective region. A film 334 is formed. The reflective film 334 is formed in a substantially square shape with a side of about 80 μm, for example. The reflection film 334 is provided with unevenness that follows the unevenness of the surface of the color filter 333.

  Next, the λ / 4 plate 335 is bonded to the upper side of the glass substrate 330a. As the λ / 4 plate 335, for example, SEH-4601351 manufactured by Sumitomo Chemical Co., Ltd. can be used. Thereafter, a positive photoresist is applied on the λ / 4 plate 335 to form a photoresist film, and an exposure and development process is performed to form an opening at a position aligned with the reflective film 334. Thereafter, the λ / 4 plate 335 is etched by wet etching to expose the reflective film 334, and then the photoresist film is removed.

  Next, the common electrode 336 is formed by depositing ITO on the entire upper surface of the glass substrate 330a by sputtering. Thereafter, for example, polyimide is applied to the entire upper surface of the glass substrate 330 a to form a vertical alignment film (not shown) that covers the surface of the common electrode 336. Thereby, the counter substrate 330 is completed.

  The TFT substrate 310 and the counter substrate 330 manufactured in this way are arranged to face each other with a spacer (not shown) interposed therebetween, and a liquid crystal having a negative dielectric anisotropy is sealed between them. A liquid crystal panel 300 is assumed. And the polarizing plate 341a is joined to the back side of the liquid crystal panel 300, and the polarizing plate 341b is joined to the front side. Further, a backlight unit is attached to the back side of the liquid crystal panel 300.

  Also in the liquid crystal display device of the present embodiment manufactured in this way, the λ / 4 plate is not interposed between the gate bus line 312 and the data bus line and the polarizing plate 341b. Even after the bonding, the inspection of defects such as the gate bus line 312 and the data bus line can be visually performed, and the defective portion can be easily identified. In this embodiment, since a λ / 4 plate is not interposed between the reflective film 334 and the polarizing plate 341a, the light output from the backlight unit and reflected by the reflective film 334 is incident on the backlight unit. Is done. Thereby, the utilization efficiency of light can be improved, and further power saving can be achieved as compared with the conventional case.

(Ninth embodiment)
FIG. 27 is a sectional view showing a liquid crystal display device according to a ninth embodiment of the present invention. Note that this embodiment is different from the eighth embodiment in that a polarizing plate is disposed on the surface of the counter substrate on the liquid crystal layer side in addition to the λ / 4 plate, and the other structures are basically the eighth. 27, the same components as those in FIG. 26 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, a black matrix 332, a color filter 333, and a reflective film 334 are formed on a glass substrate 330a serving as a base of the counter substrate 330, and then a polarizing plate 338 and λ are formed on the color filter 333 and the reflective film 334. / 4 plate 335 is joined in order. Then, on the λ / 4 plate 335, a resist film having an opening provided at a position matching the reflective region is formed, and the λ / 4 plate 335 and the polarizing plate 338 are etched using the resist film as a mask to reflect the light. The membrane 334 is exposed. Thereafter, the resist film is removed.

  Next, ITO is deposited on the upper front surface of the glass substrate 330a by sputtering to form a common electrode 336. Thereafter, for example, polyimide is applied on the common electrode 336 to form a vertical alignment film (not shown).

  The liquid crystal display device of this embodiment also has the same effect as that of the eighth embodiment.

(Tenth embodiment)
FIG. 28 is a sectional view showing a liquid crystal display device according to the tenth embodiment of the present invention. In FIG. 28, the same components as those in FIG. 14 are denoted by the same reference numerals.
In the liquid crystal display device of this embodiment, a λ / 4 plate 351 is disposed between the color filter 133 and the common electrode 134 of the counter substrate 130 as shown in FIG. Other configurations of the present embodiment are basically the same as those of the liquid crystal display device of the third embodiment shown in FIGS. Also in the liquid crystal display device of this embodiment, the same effect as that of the third embodiment can be obtained.

(Eleventh embodiment)
FIG. 29 is a sectional view showing a liquid crystal display device according to an eleventh embodiment of the present invention. 29, the same components as those in FIG. 14 are denoted by the same reference numerals.

  In the liquid crystal display device of this embodiment, as shown in FIG. 29, a polarizing plate 352 and a λ / 4 plate 351 are laminated between a color filter 133 and a common electrode 134 of the counter substrate 130. Other configurations of the present embodiment are basically the same as those of the liquid crystal display device of the third embodiment shown in FIGS. Also in the liquid crystal display device of this embodiment, the same effect as that of the third embodiment can be obtained.

  Hereinafter, various aspects of the present invention will be collectively described as supplementary notes.

(Supplementary Note 1) Liquid crystal composed of a first substrate, a second substrate disposed opposite to the first substrate, and a liquid crystal sealed between the first substrate and the second substrate. A liquid crystal panel comprising a plurality of pixels arranged in a layer;
A first λ / 4 plate and a first polarizing plate disposed on a surface opposite to the surface on the liquid crystal layer side of the first substrate;
A second λ / 4 plate and a second polarizing plate disposed on the surface of the second substrate opposite to the surface on the liquid crystal layer side,
On the surface of the first substrate on the liquid crystal layer side, a plurality of gate bus lines to which scanning signals are supplied, a plurality of data bus lines to which display signals are supplied, and the scanning provided for each pixel. A switching element driven by a signal and a pixel electrode provided for each pixel and supplied with the display signal via the switching element are formed,
At least one of the first λ / 4 plate and the first polarizing plate has an opening at a position aligned with at least one of the gate bus line and the data bus line. A liquid crystal display device.

  (Supplementary note 2) The liquid crystal display device according to supplementary note 1, wherein the pixel electrode is divided into a transmissive electrode that transmits light and a reflective electrode that reflects light.

  (Supplementary Note 3) In Supplementary Note 2, at least one of the first λ / 4 plate and the first polarizing plate is provided with an opening at a position matching the reflective electrode. The liquid crystal display device described.

  (Additional remark 4) The said transparent electrode is electrically connected to the said switching element, The liquid crystal display device of Additional remark 2 characterized by the above-mentioned.

  (Supplementary note 5) The liquid crystal display device according to supplementary note 2, wherein the reflective electrode is connected to the transparent electrode.

  (Supplementary note 6) The liquid crystal display device according to supplementary note 2, wherein an auxiliary capacitance bus line constituting an auxiliary capacitance is formed between the reflective electrode and the first substrate.

  (Supplementary note 7) The liquid crystal display device according to supplementary note 1, further comprising a backlight unit that irradiates the liquid crystal panel from the first substrate side.

  (Additional remark 8) The alignment control member which controls the alignment direction of a liquid crystal molecule is provided on the surface by the side of the said liquid crystal layer of at least one of the said 1st and 2nd board | substrates, The additional remark 1 characterized by the above-mentioned. A liquid crystal display device according to 1.

  (Supplementary note 9) The liquid crystal display device according to supplementary note 1, wherein dielectric anisotropy of the liquid crystal is negative.

(Additional remark 10) The liquid crystal which consists of a 1st board | substrate, the 2nd board | substrate arrange | positioned facing the said 1st board | substrate, and the liquid crystal enclosed between the said 1st board | substrate and the said 2nd board | substrate. A liquid crystal panel comprising a plurality of pixels arranged in a layer;
A first λ / 4 plate and a first polarizing plate disposed on the first substrate side;
A second λ / 4 plate and a second polarizing plate disposed on the second substrate side;
On the surface of the first substrate on the liquid crystal layer side, a plurality of gate bus lines to which scanning signals are supplied, a plurality of data bus lines to which display signals are supplied, and the scanning provided for each pixel. A switching element driven by a signal, and a reflective electrode provided for each pixel and supplied with the display signal via the switching element;
The liquid crystal display device according to claim 1, wherein the first λ / 4 plate is disposed on a surface of the first substrate on the liquid crystal layer side, and an opening is provided at a position matching the reflective electrode.

  (Supplementary note 11) The liquid crystal display device according to supplementary note 10, wherein the first polarizing plate is disposed on a surface side opposite to the surface on the liquid crystal layer side of the first substrate.

  (Supplementary Note 12) The first polarizing plate is disposed between the first λ / 4 plate and the first substrate, and an opening is provided at a position matching the reflective electrode. Item 13. The liquid crystal display device according to appendix 10,

  (Supplementary Note 13) The second λ / 4 plate and the second polarizing plate are both disposed on a surface opposite to the surface on the liquid crystal layer side of the second substrate. The liquid crystal display device according to appendix 10.

  (Supplementary note 14) The liquid crystal display device according to supplementary note 10, wherein the second λ / 4 plate is disposed on a surface of the second substrate on the liquid crystal layer side.

  (Supplementary note 15) The liquid crystal display device according to supplementary note 14, wherein the second polarizing plate is disposed on a surface side of the second substrate opposite to the surface on the liquid crystal layer side.

  (Supplementary note 16) The liquid crystal display device according to supplementary note 14, wherein the second polarizing plate is disposed on a surface of the second substrate on the liquid crystal layer side.

  (Supplementary note 17) The liquid crystal display device according to supplementary note 10, having a reflection region in which the reflection electrode is disposed and a transmission region in which a transparent electrode that transmits light is disposed in one pixel.

  (Supplementary note 18) The supplementary note 17, wherein an edge of the transparent electrode overlaps at least one of the gate bus line and the data bus line when viewed from a direction perpendicular to the first substrate. A liquid crystal display device according to 1.

  (Supplementary note 19) The liquid crystal display device according to supplementary note 10, wherein the surface of the reflective electrode is provided with irregularities for irregularly reflecting light.

  (Additional remark 20) Between the said reflective electrode and said 1st board | substrate, the insulating film by which the unevenness | corrugation was provided is arrange | positioned, and the unevenness | corrugation of the surface of the said reflective electrode was formed by the unevenness | corrugation of the said insulating film. Item 20. The liquid crystal display device according to appendix 19, wherein

  (Supplementary note 21) The liquid crystal display device according to supplementary note 20, wherein the insulating film is made of a resin.

  (Supplementary note 22) The liquid crystal display device according to supplementary note 10, wherein an auxiliary capacitor bus line constituting an auxiliary capacitor is arranged between the reflective electrode and the first substrate.

  (Supplementary note 23) The liquid crystal display device according to supplementary note 10, further comprising a backlight unit that irradiates the liquid crystal panel from the first substrate side.

  (Supplementary note 24) The liquid crystal according to supplementary note 10, wherein an alignment control member for controlling an alignment direction of liquid crystal molecules is provided on at least one of the first substrate and the second substrate. Display device.

  (Supplementary note 25) The liquid crystal display device according to supplementary note 10, wherein dielectric anisotropy of the liquid crystal is negative.

(Supplementary Note 26) A liquid crystal composed of a first substrate, a second substrate disposed opposite to the first substrate, and a liquid crystal sealed between the first substrate and the second substrate. In a liquid crystal display device having a liquid crystal panel composed of layers and provided with a plurality of pixels arranged,
The first substrate includes a plurality of gate bus lines to which a scanning signal is supplied, a plurality of data bus lines to which a display signal is supplied, and a switching element provided for each pixel and driven by the scanning signal. A transparent electrode provided for each pixel and supplied with the display signal via the switching element;
A reflective film formed on the surface of the second substrate on the liquid crystal layer side so as to face at least a part of the transparent electrode, and a λ / 4 plate having an opening at a position matching the reflective film And a liquid crystal display device.

  (Supplementary note 27) The liquid crystal display device according to supplementary note 26, wherein the surface of the reflective film is provided with irregularities for irregularly reflecting light.

  (Additional remark 28) It has the resin film by which the unevenness | corrugation was provided in the surface between the said reflecting film and the said 2nd board | substrate, The unevenness | corrugation of the said reflecting film is formed by the unevenness | corrugation of the said resin film, The liquid crystal display device according to appendix 27.

  (Supplementary note 29) The liquid crystal display device according to supplementary note 28, wherein the resin film is a color filter.

  (Supplementary note 30) The liquid crystal display device according to supplementary note 26, wherein a polarizing plate is disposed between the λ / 4 plate and the second substrate.

  (Supplementary note 31) The liquid crystal display device according to supplementary note 26, wherein a polarizing plate is disposed on a surface opposite to the surface on the liquid crystal layer side of the second substrate.

(Supplementary Note 32) Forming a plurality of gate bus lines to which scanning signals are supplied and a plurality of data bus lines to which display signals are supplied on the first surface of the first substrate;
Bonding a λ / 4 plate on the second surface of the first substrate;
Forming a photoresist film on the λ / 4 plate;
Exposing the photoresist film and then developing to expose the λ / 4 plate at a position aligned with the gate bus line and the data bus line;
Etching the λ / 4 plate using the photoresist film as a mask;
Removing the photoresist film;
And a step of disposing a second substrate so as to face the first substrate and enclosing a liquid crystal between them.

  (Supplementary note 33) The supplementary note 32 is characterized in that the photoresist film is formed of a negative photoresist and the photoresist film is exposed from a light source disposed on the first surface side of the first substrate. The manufacturing method of the liquid crystal display device of description.

(Supplementary Note 34) Forming a plurality of gate bus lines to which a scanning signal is supplied and a plurality of data bus lines to which a display signal is supplied on the first surface of the first substrate;
Bonding a λ / 4 plate on the first surface of the first substrate;
Forming a photoresist film on the λ / 4 plate;
Exposing the photoresist film and then developing to expose the λ / 4 plate at a position aligned with the gate bus line and the data bus line;
Etching the λ / 4 plate using the photoresist film as a mask;
Removing the photoresist film;
And a step of disposing a second substrate so as to face the first substrate and enclosing a liquid crystal between them.

  (Supplementary note 35) The supplementary note 34, wherein the photoresist film is formed of a negative photoresist, and the photoresist film is exposed from a light source disposed on a second surface side of the first substrate. The manufacturing method of the liquid crystal display device of description.

FIG. 1 is a schematic view showing the structure of a conventional transflective liquid crystal display device. FIG. 2 is a schematic diagram showing a light state during black display of a conventional transflective liquid crystal display device. FIG. 3 is a schematic diagram showing a light state during white display of a conventional transflective liquid crystal display device. FIG. 4 is a plan view showing the liquid crystal display device according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view taken along the line II of FIG. 6 is a cross-sectional view taken along line II-II in FIG. 7A to 7D are cross-sectional views illustrating a method of forming the opening of the λ / 4 plate of the liquid crystal display device according to the first embodiment. FIG. 8 is a plan view showing a liquid crystal display device according to a second embodiment of the present invention. 9 is a cross-sectional view taken along line III-III in FIG. FIG. 10 is a cross-sectional view (part 1) illustrating the method for manufacturing the liquid crystal display device of the second embodiment. FIG. 11 is a cross-sectional view (part 2) illustrating the method for manufacturing the liquid crystal display device of the second embodiment. FIG. 12 is a schematic diagram illustrating a light state during black display of the transflective liquid crystal display device according to the second embodiment. FIG. 13 is a plan view showing a liquid crystal display device according to a third embodiment of the present invention. 14 is a cross-sectional view taken along line IV-IV in FIG. FIG. 15 is a cross-sectional view (part 1) illustrating the method for manufacturing the TFT substrate of the liquid crystal display device of the third embodiment. FIG. 16 is a cross-sectional view (part 2) illustrating the method for manufacturing the TFT substrate of the liquid crystal display device of the third embodiment. FIG. 17 is a cross-sectional view showing a modification (No. 1) of the third embodiment, and shows an example in which the edge of the transparent electrode is formed so as to overlap the gate bus line. FIG. 18 is a cross-sectional view showing a modification (No. 2) of the third embodiment, and shows an example in which the edge of the transparent electrode is formed so as to overlap the data bus line. FIG. 19 is a cross-sectional view showing a liquid crystal display device according to a fourth embodiment of the present invention. FIG. 20 is a cross-sectional view showing a liquid crystal display device according to a fifth embodiment of the present invention. FIG. 21 is a schematic diagram showing a light state during black display of the transflective liquid crystal display device of the fifth embodiment. FIG. 22 is a cross-sectional view showing a liquid crystal display device according to a sixth embodiment of the present invention. FIG. 23 is a cross-sectional view showing a first modification of the sixth embodiment, showing an example in which the edge of the transparent electrode is formed so as to overlap the gate bus line. FIG. 24 is a cross-sectional view showing a modification (No. 2) of the sixth embodiment, and shows an example in which the edge of the transparent electrode is formed so as to overlap the data bus line. FIG. 25 is a cross-sectional view showing a liquid crystal display device according to a seventh embodiment of the present invention. FIG. 26 is a sectional view showing a liquid crystal display device according to an eighth embodiment of the present invention. FIG. 27 is a sectional view showing a liquid crystal display device according to a ninth embodiment of the present invention. FIG. 28 is a sectional view showing a liquid crystal display device according to the tenth embodiment of the present invention. FIG. 29 is a sectional view showing a liquid crystal display device according to an eleventh embodiment of the present invention.

Explanation of symbols

10, 100, 200, 300 ... liquid crystal panel,
11, 110, 210, 310 ... substrate (TFT substrate),
12, 130.330 ... Substrate (counter substrate)
13, 140, 340 ... liquid crystal layer,
14a, 14b, 142a, 142b, 242a, 242b, 261, 341a, 341b, 338, 352... Polarizing plate,
15a, 15b, 141a, 141b, 241a, 241b, 252, 271, 320, 335, 336, 351 ... λ / 4 plate,
17a, 220 ... reflective electrode,
17b, 120a, 120b, 120c, 222a, 222b, 222c, 332a, 332b, 332c ... transparent electrodes,
18, 134, 336 ... common electrode,
20 ... Backlight unit,
110a, 130a, 210a, 310a, 330a ... glass substrate,
112, 212, 312 ... gate bus lines,
113, 213, 313 ... auxiliary capacity bus line,
114, 119, 214, 219, 221, 314, 319 ... insulating film,
115, 215 ... data bus line,
116, 216 ... TFT,
118, 218 ... auxiliary capacitance electrode,
132,332 ... black matrix,
133,333 ... color filter,
135 ... Protrusions (alignment control structures),
150, 250 ... opening (opening of λ / 4 plate),
151, 251, 253 ... Photoresist film,
160, 260 ... opening (opening of polarizing plate),
270 ... Transparent resin film,
334: Reflective film.

Claims (4)

A first substrate, a second substrate disposed opposite to the first substrate, and a liquid crystal layer made of liquid crystal sealed between the first substrate and the second substrate. A liquid crystal panel provided with a plurality of pixels arranged;
A first λ / 4 plate and a first polarizing plate disposed on a surface opposite to the surface on the liquid crystal layer side of the first substrate;
A second λ / 4 plate and a second polarizing plate disposed on the surface of the second substrate opposite to the surface on the liquid crystal layer side,
On the surface of the first substrate on the liquid crystal layer side, a plurality of gate bus lines to which scanning signals are supplied, a plurality of data bus lines to which display signals are supplied, and the scanning provided for each pixel. A switching element driven by a signal and a pixel electrode provided for each pixel and supplied with the display signal via the switching element are formed,
The first λ / 4 plate, or the first λ / 4 plate and the first polarizing plate have an opening at a position aligned with at least one of the gate bus line and the data bus line. The light reflected from at least one of the gate bus line and the data bus line is transmitted through the first λ / 4 plate and the first polarizing plate through the opening. A characteristic liquid crystal display device.   The liquid crystal display device according to claim 1, wherein the pixel electrode is divided into a transmissive electrode that transmits light and a reflective electrode that reflects light.   3. The liquid crystal display according to claim 2, wherein at least one of the first λ / 4 plate and the first polarizing plate is provided with an opening at a position matching the reflective electrode. apparatus. Forming a plurality of gate bus lines to which scanning signals are supplied and a plurality of data bus lines to which display signals are supplied on the first surface of the first substrate;
Bonding a λ / 4 plate on the second surface of the first substrate;
Forming a photoresist film on the λ / 4 plate;
Exposing the photoresist film and then developing to expose the λ / 4 plate at a position aligned with the gate bus line and the data bus line;
Etching the λ / 4 plate using the photoresist film as a mask to form openings in the λ / 4 plate to match the gate bus lines and the data bus lines;
Removing the photoresist film;
Disposing a second substrate facing the first substrate and enclosing a liquid crystal between them;
And a step of visually inspecting the gate bus line and the data bus line for defects from the opening of the λ / 4 plate.

Images