JP5074119B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid crystal display device, and more particularly to a transflective IPS (In Plane Switching) method, a transflective TN (Twisted Nematic) method, a transflective VA (Vertically Aligned) method liquid crystal display device, and a method for manufacturing the same. .

  Currently, transmissive liquid crystal display devices with a wide viewing angle such as the IPS method and the VA method are widely used as monitors for various devices, and are used as televisions with improved response characteristics. On the other hand, liquid crystal display devices are widely used in portable information devices such as mobile phones and digital cameras. Portable information devices are mainly used by individuals, but recently, the number of display units with variable angles is increasing, and a wide viewing angle is desired because they are often observed from an oblique direction.

  A display device for a portable information device is used in various environments including outdoors from a sunny day to a dark room, and thus it is desired to be a transflective type. A transflective liquid crystal display device has a reflective display portion and a transmissive display portion in one pixel.

  The reflective display unit reflects and displays light incident from the surroundings using a reflector, and the contrast ratio is constant regardless of the ambient brightness, so it is a relatively bright environment from outdoor to indoors in fine weather. Good display is obtained below. On the other hand, the transmissive display unit uses a backlight and has a constant luminance regardless of the environment, so that a display with a high contrast ratio can be obtained in a relatively dark environment from indoors to a dark room. A transflective liquid crystal display device having both of these characteristics can display with a high contrast ratio in a wide range of environments including the outdoors from a sunny day to a dark room.

  Conventionally, it has been expected that a reflective display and a transmissive display with a wide viewing angle can be obtained at the same time if the IPS system known for the transmissive display with a wide viewing angle is made a transflective type. For example, Patent Document 1 describes a transflective IPS system.

  In this transflective IPS liquid crystal display device, retardation plates are arranged on the entire upper and lower outer surfaces of a liquid crystal panel in which a liquid crystal layer is sealed between two transparent substrates. The plate has a viewing angle dependency. For this reason, even if the phase difference and the axial arrangement of the liquid crystal layer and the plurality of phase difference plates are optimized in the normal direction of the liquid crystal layer, the optimum conditions for dark display are rapidly deviated as the distance from the normal direction increases.

  The viewing angle dependence of the retardation plate can be reduced by adjusting the refractive index in the thickness direction of the retardation plate, but cannot be completely eliminated. As a result, in the transflective IPS system, the increase in dark display transmittance in the viewing angle direction is large, and the viewing angle characteristics of the transmissive display are lower than in the transmissive IPS system.

  Non-Patent Document 1 discloses an installation structure and display characteristics when a retardation plate (retardation layer) is built in the panel instead of an externally installed retardation plate.

  In Patent Document 2, in the VA method, the retardation layer is disposed so as to be close to the liquid crystal layer, and is patterned and disposed only on the reflective display portion. However, application to the IPS system that gives a wide viewing angle transmission display is not considered.

  Patent Document 3 describes a transflective IPS liquid crystal display device that applies a lateral electric field to a liquid crystal layer. This transflective IPS liquid crystal display device includes a transmissive display portion and a reflective display portion in one pixel. The reflection display part is provided with a built-in retardation plate having a retardation of ½ wavelength. Further, by setting the retardation of the liquid crystal layer of the reflection display part to ¼ wavelength, it is possible to remove the dark place from the bright place. Reflective display is possible in a wide range of environments, and high-quality transmissive display is possible with a wide viewing angle. The built-in retardation plate is made of molecules having a birefringence such as liquid crystal molecules.

  The manufacturing procedure of the substrate on the color filter side of the liquid crystal display device is as follows. That is, first, after forming a black matrix layer and an RGB resist layer, a planarizing layer for planarizing them is formed. Thereafter, an alignment film for causing the alignment function of the built-in retardation plate is formed, and a rubbing process is performed. By applying the material of the built-in retardation plate in this state, an orientation state is generated, and a built-in retardation plate can be formed. By exposing and developing this, an unnecessary portion (a portion corresponding to the transmissive display portion) can be removed, and a retardation plate can be incorporated in a predetermined portion (a portion corresponding to the reflective display portion).

  Here, an organic solvent is required for development of the retardation plate layer, and the burden on the cost, environment, and process is large. In this respect, after coating the material of the retardation plate over the entire surface, only the portion that requires the retardation is photocured by mask exposure, and then the entire portion is photocured while heating, so that the portion that does not require retardation There is a method of eliminating the phase difference of the resin and curing it (see Non-Patent Document 1). According to this method, the organic development process can be omitted.

However, when a portion that does not require a phase difference is extinguished by heating and photocured, the photopolymerization initiator for curing the phase difference material evaporates due to the high heating temperature. In particular, the initiator tends to be insufficient at the alignment film interface for aligning the retardation plate, and a small amount of unreacted liquid crystal monomer with acrylate remains. In addition, it is difficult to completely react all acrylate-attached liquid crystal monomers even when irradiated with light, and uncured monomers are reorientated, so that the phase difference slightly remains in areas where no phase difference is required. Inevitable.
Japanese Patent Laid-Open No. 11-242226 JP 2003-279957 A JP 2005-338256 A c. Doornkamp et al. , Philips Research, “Next generation mobile LCDs in-cell retarders.” International Display Worksshop 2003, p685 (2003).

  In the transmissive IPS, TN, and VA systems, the liquid crystal layer is homogeneously aligned, and the polarizing plates (upper and lower polarizing plates) placed on the outer surfaces of the first substrate and the second substrate are arranged so that the transmission axes are orthogonal to each other. And one of the transmission axes is made parallel to the alignment direction of the liquid crystal layer. The light incident on the liquid crystal layer is linearly polarized light, and its vibration direction is parallel to the alignment direction of the liquid crystal layer, so that no phase difference is given by the liquid crystal layer. As a result, a dark display with a low transmittance can be realized, and since no retardation layer (retardation plate) is interposed between the liquid crystal layer and the polarizing plate, no extra phase difference occurs in the viewing angle direction, and a dark display with a wide viewing angle is achieved. realizable. Thus, the transmission type IPS, TN, and VA systems do not essentially require a retardation layer (retardation plate).

  A transflective liquid crystal display device has a reflective display portion and a transmissive display portion, which have substantially different optical conditions for dark display, in one pixel. That is, in the reflective display unit, light enters the polarizing plate on the substrate (first substrate) side of the upper surface of the liquid crystal panel constituting the liquid crystal display device, is reflected by the reflective plate inside the liquid crystal panel, and then again. It passes the polarizing plate on the upper surface and heads for the user. On the other hand, in the transmissive display portion, light is incident from the polarizing plate on the substrate (second substrate) side on the lower surface of the liquid crystal panel, and then passes through the polarizing plate on the upper surface of the liquid crystal panel and travels toward the user.

  Due to such a difference in optical path, the phase difference of light that is darkly displayed differs between the reflective display portion and the transmissive display portion by a quarter wavelength. For this reason, when the reflective display portion is bright, the transmissive display portion is dark, or vice versa, and the reflective display portion and the transmissive display portion have different applied voltage dependencies. In order to make them dependent on the same applied voltage, the phase difference between the reflective display portion and the transmissive display portion must be shifted by a quarter wavelength by some method.

  In the conventional transflective IPS, TN, and VA systems, retardation plates are arranged on the entire surface (outer surface) above and below the liquid crystal panel. Among these, the retardation plate on the upper side (first substrate side) of the liquid crystal panel is light incident on the reflective display portion from the outside, light reflected by the reflective plate of the reflective display portion, and light that has passed through the transmissive display portion. Pass through. As described above, the upper retardation plate acts on both the reflective display unit and the transmissive display unit. On the other hand, the phase difference plate on the lower side (second substrate side) of the liquid crystal panel acts only on the transmissive display unit because only the light source light incident on the transmissive display unit passes therethrough. By utilizing the difference in the action of the upper and lower phase plates with respect to the reflective display portion and the transmissive display portion, the phase difference between them is shifted by a quarter wavelength. However, when the retardation plate is interposed between the liquid crystal layer and the polarizing plate, an extra phase difference is generated in the viewing angle direction, and the viewing angle characteristics of dark display are deteriorated.

  Further, in the transflective IPS, TN, and VA systems in which the function of a retardation plate as disclosed in Patent Document 3 is incorporated in a liquid crystal panel and used as a retardation layer, a retardation layer is formed only on a reflective display portion. To do. For the formation of the retardation layer, patterning using a photolithography method in which a retardation layer forming material mainly composed of a liquid crystal monomer with acrylate is applied and exposed to a photomask is employed.

  There is a development-free manufacturing process disclosed in the method of Non-Patent Document 1. After patterning the alignment layer by a photolithography method on the phase difference layer forming material, it is heated to a temperature higher than the nematic / isotropic phase transition temperature to expose the unexposed portion to an isotropic layer. This is a manufacturing process in which a transparent layer can be formed in the same layer as the retardation layer of the reflecting portion. However, simply applying this process requires an alignment film for orienting the phase difference plate in the reflective part and the transmissive part, and the coloring of the alignment film material also remains in the transmissive part. May have adverse effects. Moreover, the method of nonpatent literature 1 must be performed in nitrogen atmosphere, and an apparatus becomes large and is not realistic. Furthermore, pattern thickening due to overexposure may be aggravated because it is equivalent to the development process or because there is no reduction in retardation plate due to development. Also, not all of the retardation material is cured by exposure in the heated state, and the uncured material is oriented again if it remains in the film, particularly at the interface of the underlying alignment film. The phase difference remains, and the contrast of transmissive display is reduced.

  An object of the present invention is to reduce transflective display characteristics by forming a retardation layer of a reflective display unit within the tolerance of a designed pattern in a liquid crystal display device incorporating a retardation plate in the reflective display unit. And providing a simple manufacturing process that can suppress coloring of the transmissive display portion.

  In order to solve the above problems, in the present invention, an alignment film for aligning the retardation plate is disposed only in a portion where the retardation plate is disposed, thereby preventing a decrease in transmittance of the transmission portion. Further, in the manufacturing process that does not require development, since there is no alignment film on the base of the retardation material that becomes transparent at the transmission part, the phase difference remaining in the transmission part is eliminated, and the contrast of the transmission part is prevented from being lowered.

For example , a liquid crystal layer is sandwiched between a first substrate and a second substrate facing each other , and a reflective display portion and a transmissive display portion are provided, and a color filter layer is formed on the first substrate, and the reflective display portion a liquid crystal display device incorporating a phase difference plate on the liquid crystal layer side of the first substrate corresponding to a flattening layer for flattening the color filter layer of the first substrate, the reflective display unit A base layer provided in contact with the planarization layer and not provided in the transmissive display unit, and the base layer on the liquid crystal layer side of the first substrate and the flat layer across the reflective display unit and the transmissive display unit anda resin layer formed on the layer, in the reflective display part, the resin layer is oriented by the underlying layer acts as a retardation plate, in the transmissive display section, the underlying layer is not optically transparent orientation the resin layer by the absence of And wherein the function child as a layer.

Further , in a method of manufacturing a liquid crystal display device in which a liquid crystal layer is sandwiched between a first substrate and a second substrate that are opposed to each other, a reflection display unit and a transmission display unit are combined, and a retardation plate is incorporated in the reflection display unit . the underlayer, the a selectively formed to that foundation layer forming step to the reflective display unit not formed in the transmissive display part, and performing a rubbing treatment on the base layer described above is formed, the rubbed underlayer the reflective display portion and over the transmissive display section, the steps of applying a composition mainly composed of a liquid crystalline monomer and a polymerization initiator having an acrylate crosslinking group, the composition described above is applied, the liquid crystalline monomer containing above the melting point of, and with heating at a temperature lower than the nematic isotropic phase transition temperature of the liquid crystalline monomer, the reflective display part and over the transmissive display section is exposed, as engineering of the composition Ru cured by crosslinking It has, in the step of the crosslinking curing, above the reflective display unit to form a phase difference plate by aligning said composition by the underlying layer, the composition by the underlying layer is not a the transmissive display unit objects and features that you form optically transparent layer by not oriented.
Further, a liquid crystal layer sandwiched between the first substrate and the second substrate facing, both a transmissive display and the reflective display portion, the color filter layer is formed on the first substrate, the reflective display part In a manufacturing method of a liquid crystal display device including a corresponding retardation plate on the liquid crystal layer side of the corresponding first substrate, the color filter layer of the first substrate including the retardation plate is planarized with a transparent resin . forming a layer, a step of applying said phase difference plate photocurable resin composition serving as a base layer of the planarization layer, Ri by the resin composition of the reflective display part in the mask exposure curing The base layer is selectively formed on the reflective display unit without forming the base layer on the reflective display unit by the curing process to be performed and the development process for removing the uncured part of the uncured resin composition of the transmissive display unit. and a step, the formed underlayer on Coating the liquid crystal monomer having an acrylate crosslinking group and a composition mainly composed of a polymerization initiator over the reflective display portion and the transmissive display portion, and in the step of crosslinking and curing, the reflection In the display part, a retardation plate is formed by orienting the composition by the underlayer, and in the transmissive display part, an optically transparent layer is formed by not orienting the composition due to the absence of the underlayer. and wherein the child.

  A liquid crystal display device to which an embodiment of the present invention is applied will be described below.

<First Embodiment>
FIG. 1 is a plan view illustrating a configuration example of one pixel of a liquid crystal panel constituting the liquid crystal display device to which the first embodiment is applied. 2 is a cross-sectional view taken along the line AA ′ of FIG. 1 for explaining a schematic configuration example of one pixel of the liquid crystal panel shown in FIG.

  The liquid crystal panel includes a first substrate 31, a liquid crystal layer 10, and a second substrate 32, and the liquid crystal layer 10 is held in a facing gap between the first substrate 31 and the second substrate 32. .

  On the main surface (inner surface) of the first substrate 31, a color filter 45 partitioned by a black matrix 35, a planarization layer (first protective film) 36, and a third alignment film (built-in retardation layer) Alignment film) 37, a built-in retardation layer (hereinafter simply referred to as retardation layer) 38, a protective layer (second protective film) 40 of the retardation layer 38, and a first alignment film 33. They are stacked in order.

  However, the third alignment film 37, which is an alignment film for the retardation layer, is disposed only in the transmissive display portion RA and is not disposed in the transmissive display portion TA. For this reason, the retardation layer 38 is formed only in the transmissive display portion RA and is not formed in the transmissive display portion TA. In the transmissive display portion TA, a transparent layer 38n having no phase difference exists instead of the phase difference layer 38. The transparent layer 38n is made of the same material as the retardation layer 38, and is a layer cured without being imparted with retardation.

  The third alignment film 37 is provided with an alignment control ability for controlling the alignment of the forming material of the retardation layer 38 made of the liquid crystal layer composition. Further, the first alignment film 33 is provided with an alignment control ability for controlling the initial alignment of the liquid crystal layer 10 for controlling display light.

  The main surface of the second substrate 32 has a thin film transistor TFT for driving a pixel. The thin film transistor TFT is connected to the scanning wiring 21, the signal wiring 22, and the pixel electrode 28.

  In addition, a common wiring 23 and a common electrode 29 are provided. Here, the thin film transistor TFT has an inverted staggered structure, and its channel portion is formed of an amorphous silicon (a-Si) layer 25. The scanning wiring (gate) 21 and the source / drain electrode 24 are insulated by a first insulating layer 51. A second insulating layer 52 is on the thin film transistor TFT.

  The scanning wiring 21 and the signal wiring 22 intersect in the row direction and the column direction to form a two-dimensional matrix. The thin film transistor TFT is generally located near the intersection.

  The common wiring 23 is arranged in parallel with the scanning wiring 21 and is connected to the common electrode 29 through the second through hole 27. The pixel electrode 28 and the source / drain electrode 24 of the thin film transistor TFT are coupled by a first through hole 26. On the pixel electrode 28, there is a second alignment film 34, which is provided with an alignment control ability for controlling the initial alignment of the liquid crystal layer 10.

  The first substrate 31 is preferably made of borosilicate glass with few ionic impurities and has a thickness of, for example, 0.5 mm. The color filter 45 partitioned by the black matrix 35 has red, green, and blue portions (color subpixels) arranged repeatedly in a stripe pattern, and each stripe is parallel to the signal electrode 22. The unevenness of the formation surface of the black matrix 35 and the color filter 45 is flattened by a resinous flattening layer (first protective film, overcoat film) 36. The first alignment film 33 is a polyimide organic film and is subjected to an alignment process by a rubbing method.

  The second substrate 32 is suitably borosilicate glass similar to the first substrate 31 and has a thickness of 0.5 mm, for example. Similar to the first alignment film 33, the second alignment film 34 is a horizontally oriented polyimide organic film. The signal wiring 22, the scanning wiring 21, and the common wiring 23 are formed of aluminum (Al), an alloy thereof (alloy of aluminum and neodymium: Al—Nd), chromium (Cr), or the like. A transparent conductive film such as indium tin oxide (indium tin oxide: ITO) is desirable, and the common electrode 29 is desirably formed of a transparent conductive film such as ITO.

  The pixel electrode 28 has slits 30 parallel to the scanning wiring 21 and the pitch of the slits 30 is about 4 μm. The pixel electrode 28 and the common electrode 29 are separated by a third insulating layer 53 having a layer thickness of 0.5 μm, and an electric field is formed between the pixel electrode 28 and the common electrode 29 when a voltage is applied. The electric field is distorted in an arch shape due to the influence of the third insulating layer 53 and passes through the liquid crystal layer 10. As a result, an orientation change occurs in the liquid crystal layer 10 when a voltage is applied. In addition, said numerical value is an example including the other numerical value by this specification and drawing, and this invention is not limited to this numerical value.

  The common wiring 23 has a structure protruding into the pixel electrode 28 at a portion intersecting with the pixel electrode 28. In FIG. 1, a portion where the common wiring 23 overlaps with the pixel electrode 28 is a reflective display portion RA, and reflects light as indicated by reflected light 62. In other overlapping portions of the pixel electrode 28 and the common electrode 29, as shown by the transmitted light 61, the backlight light passes and becomes the transmissive display portion TA. Since the optimal layer thickness of the liquid crystal layer is different between the transmissive display portion TA and the reflective display portion RA, a step is generated at the boundary. In order to shorten the boundary between the transmissive display portion TA and the reflective display portion RA, the transmissive display portion TA and the reflective display portion RA are arranged so that the boundary is parallel to the short side of the pixel.

  Thus, if the wiring such as the common wiring 23 is also used as a reflector, an effect of reducing the manufacturing process can be obtained. If the common wiring 23 is made of aluminum having a high reflectance, a brighter reflective display can be obtained. The same effect can be obtained even if the common wiring 23 is made of chromium and a reflector made of aluminum or silver alloy is separately formed.

  The liquid crystal layer 10 is a liquid crystal layer composition exhibiting positive dielectric anisotropy in which the dielectric constant in the alignment direction is larger than that in the normal direction. Here, the birefringence is 0.067 at 25 ° C., and shows a nematic phase in a wide temperature range including a room temperature region. In addition, during a holding period when driving at a frequency of 60 Hz using a thin film transistor, a high resistance value that does not cause flicker by sufficiently holding reflectance and transmittance is exhibited.

  Next, a manufacturing process of the liquid crystal panel configured as described above will be described with reference to FIG.

  First, the black matrix 35 and the color filter 45 are formed on the main surface of the first substrate, and the surface is covered with the first protective film 36 and planarized (P-1). Next, an alignment film (third alignment film) 37 for a retardation layer, which is a photosensitive polyimide material, is applied on the first protective film 36 (P-2). Then, the portion corresponding to the reflective display portion RA is irradiated with ultraviolet light using an exposure mask, the imide group is photopolymerized and cured, and the unexposed portion (transmission display portion) is removed with an alkali developer ( P-3).

  Examples of the alignment film (third alignment film) 37 for the retardation layer include a method in which a compound having a photosensitive group is mixed with a polyimide precursor (Japanese Patent Laid-Open No. 54-109828), and a functional group in the polyimide precursor. A material proposed by a method of reacting a functional group of a compound having a photosensitive group with a functional group to give a photosensitive group (Japanese Patent Laid-Open Nos. 56-24343, 60-1000014, etc.) it can. This material is a polymer having an acidic group. By having an acidic group, the polymer becomes soluble in an alkaline aqueous solution used as a developer, and the solubility of the exposed portion increases after exposure. Thereby, since the melt | dissolution rate of an exposed part and an unexposed part differs, the pattern of a relief structure can be formed.

  As the alkaline aqueous solution, an aqueous solution exhibiting alkalinity in which tetramethylammonium hydroxide, metal hydroxide, amine and the like are dissolved in water is preferable. Examples of the acidic group include a carboxyl group, a phenolic hydroxyl group, and a sulfone group. The polymer preferably has a carboxyl group or a phenolic hydroxyl group. Polymer types include polyimide precursors such as polyamic acid, polyamic acid ester, polyamic acid amide, polyhydroxyamide as polyoxazole precursor, polyimide, polybenzoxazole, and other polymers with excellent heat resistance. It is preferable because the film properties such as the heat resistance of the pattern to be formed are excellent.

  As for the photosensitive polyimide composition, a polyimide precursor composition in which a photosensitive group is introduced by an ester bond (Japanese Patent Publication No. 52-30207), a carbon-carbon double bond that can be dimerized or polymerized by actinic radiation to polyamic acid. In addition, compositions containing a compound containing an amino group and an aromatic bisazide (Japanese Patent Publication No. 3-36861) are known.

  For example, as a material of the alignment film (third alignment film) 37 for the retardation layer, photosensitive polyimide (HD5104 manufactured by Hitachi Chemical DuPont) is diluted 5 times with a diluent and applied to the first protective film 36. . Therefore, 1 wt% or less of additives are added. As an additive, for example, BYK-302, BYK-306, BYK-307, BYK-330, BYK-352, BYK-354, BYK-356, BYK-361N, BYK-370, BYK-390, manufactured by Big Chemie Japan, Examples include Flow 300, Flow 425, Flow ZFS 460, Glide 100, Glide 410, Glide 420, Glide 435, Glide A 115, and Glide ZG 400 manufactured by Tego.

For example, a photosensitive polyimide diluted solution to which BYK-333 is added at 1 wt% is applied by spin coating to have a film thickness of about 100 nm, and then exposed to N ₂ gas using an exposure apparatus for lithography. Develop with developer (tetramethylammonium hydroxide TMAH 2.38% solution). Thereafter, the polyimide can be formed only on the reflective display portion RA by curing the polyimide at a temperature of 200 ° C.

  At this stage, the substrate surface is in a state where the third alignment film 37 is formed in the reflective display area RA and the first protective film 36 is exposed in the transmissive display area TA.

  Next, an alignment control function is imparted to the third alignment film 37 of the reflective display portion RA by rubbing (P-4). At this time, the alignment control function is not given to the first protective film 36 of the transmissive display portion TA. The third alignment film 37 is horizontally aligned and has a function of determining the slow axis direction of the retardation layer 38.

  Next, a retardation layer material is applied on the third alignment film 37 (P-5). The phase difference layer material is an organic material in which a nematic liquid crystal monomer having a photoreactive acrylic group (acrylate) at the molecular end and one or more polymerization initiators (reaction initiators) are dispersed in an organic solvent. Consists of.

  Examples of liquid crystal monomers with acrylate are shown below.

  Moreover, the example of a polymerization initiator is shown below.

  Further, since it is necessary to apply a retardation material to the first protective film 36 of the transmissive display portion TA, an additive is added in an amount of 0.001 to 0.3% for the purpose of improving the wettability of the retardation material. As an additive, for example, BYK-302, BYK-306, BYK-307, BYK-330, BYK-352, BYK-354, BYK-356, BYK-361N, BYK-370, BYK-390, manufactured by Big Chemie Japan, Examples include Flow 300, Flow 425, Flow ZFS 460, Glide 100, Glide 410, Glide 420, Glide 435, Glide A 115, and Glide ZG 400 manufactured by Tego. Examples of the solvent for the retardation material include propylene glycol monomethyl ether acetate, cyclohexanone, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, methoxybutyl acetate, diethylene glycol dimethyl ether, and diethylene glycol methyl ethyl ether.

  After applying the retardation layer material, this is pre-baked for 2 to 3 minutes with a hot plate at 100 ° C. to remove the solvent, thereby forming a transparent film (P-6). In the reflective display area RA, this film is oriented in the orientation processing direction of the third orientation film 37 when pre-baked, and the function as the retardation layer 38 is given. On the other hand, the transmissive display portion TA is not oriented when pre-baked and becomes a cloudy crystallization state.

  By heating the pre-baked retardation layer material to a temperature higher than its melting point and lower than the nematic / isotropic phase transition temperature, the reflective display portion RA maintains the state where the function as the retardation layer 38 is imparted, and the transmissive display. Since the part TA exceeds the melting point, it becomes a transparent isotropic layer from the cloudy crystal state. While maintaining this heated state, the entire surface is irradiated with ultraviolet rays to photopolymerize and cure the acrylic group, thereby forming the retardation layer 38 and the transparent layer 38n (P-7).

  For example, in the PALIOcolor LC242 manufactured by BASF, the melting point is 63-70 ° C. and the nematic / isotropic phase transition temperature is 120-125 ° C. Therefore, after heating at 100 ° C. for 5 minutes, ultraviolet irradiation is performed.

  The whole surface irradiation lamp may be an ultraviolet fluorescent lamp of about 20 W arranged in parallel, but it is desirable to use a black light blue fluorescent lamp (Black-light Blue (BL-B) Fluorescent Lamp). The black light blue fluorescent lamp mainly emits near-ultraviolet light (Near-ultraviolet Light, nominal wavelength band: 300 to 400 nm), and exhibits a peak wavelength of, for example, 360 nm.

  The transmittance of the retardation layer 38 and the transparent layer 38n is 90% or more in the visible light region (for example, wavelength 400 to 800 nm).

  Since the retardation layer 38 formed here is composed of a liquid crystal polymer, the orientation of the molecules is higher than that of a conventional external retardation plate formed by stretching an organic polymer film. Has the same degree of orientation. Therefore, Δn of the retardation layer 38 is much larger than that of the external retardation plate, and can be made to be about the same as or higher than that of the liquid crystal layer 10 by appropriately adjusting the molecular structure and film forming conditions. The thickness of the external retardation plate is several tens of μm, which is nearly 10 times the thickness of the liquid crystal layer. However, if the liquid crystal polymer is used as a built-in retardation layer, the retardation layer 38 and the transparent layer are transparent. The layer thickness of the layer 38n can be greatly reduced.

  Next, a transparent organic layer is applied on the retardation layer 38 and the transparent layer 38 n to form the second protective film 40. Further, a photosensitive transparent resist is applied to the second protective film 40 and exposed to ultraviolet rays using an exposure mask. Here, patterning is performed using an exposure mask having a distribution similar to that of the reflective display area RA. Thereafter, the film thickness adjusting layer 39 is formed only on the upper layer of the retardation layer 38 by alkali development (P-8).

  If the retardation layer 38 has a Δn larger than twice that of the liquid crystal layer, the thickness becomes insufficient when the retardation of the retardation layer 38 is ½ wavelength. Therefore, by forming a film thickness adjusting layer 39 on the retardation layer 38, a quarter-wave retardation difference is ensured between the reflective display portion and the transmissive display portion.

  Next, the first alignment film 33 is applied to the uppermost layer of the main surface of the first substrate 31, and the second alignment film 34 is applied to the uppermost layer of the main surface of the second substrate 32. After the rubbing process in the crossing direction, columnar spacers are interposed in the display areas of the first substrate 31 and the second substrate 32 (P-9), and a sealing material is applied to the inner side of the outer peripheral edge to both substrates. Are assembled together, and the liquid crystal layer 10 is sealed inside.

  Finally, the first polarizing plate 41 and the second polarizing plate 42 are disposed outside the first substrate 31 and the second substrate 32, respectively. The transmission axes of the first polarizing plate 41 and the second polarizing plate 42 are arranged so as to be orthogonal and parallel to the liquid crystal layer alignment direction, respectively.

  In the present embodiment, the light diffusive adhesive layer 43 in which a large number of transparent microspheres having a refractive index different from that of the adhesive material is mixed is used for the adhesive layer 43 of the first polarizing plate 41. With such a configuration, the optical path of incident light is expanded by utilizing the effect of refraction caused by the difference in refractive index between the adhesive material and the microsphere. Thereby, it is possible to reduce iridescent coloring caused by interference of reflected light between the pixel electrode 28 and the common electrode 29. However, the configuration of the adhesive layer 43 is not limited to this, and it goes without saying that an adhesive material without microspheres may be used.

  In the transmissive display portion TA of the liquid crystal panel manufactured as described above, the transmission axis of the first polarizing plate 41 and the transmission axis of the second polarizing plate 42 are orthogonal to each other, and the latter is parallel to the crystallographic scrap alignment direction. is there. Since this is the same configuration as that of the transmissive IPS system, a wide viewing angle that can withstand monitor applications can be obtained for transmissive display as in the transmissive IPS system.

  On the other hand, the reflective display portion RA includes a homogeneously oriented liquid crystal layer 10, a retardation layer 38, and a first polarizing plate 41. The relationship between the slow axis of the retardation layer 38, the alignment direction of the liquid crystal layer, and the transmission axis angle of the first polarizing plate 41 is as follows. That is, since the slit 30 of the pixel electrode 28 shown in FIG. 1 is perpendicular to the signal wiring 22, the electric field direction is parallel to the direction of the signal wiring 22. When the azimuth angle is defined counterclockwise, the alignment direction of the liquid crystal layer is −75 degrees with respect to the electric field direction, which stabilizes the alignment change during voltage application and reduces the borrowed voltage while the alignment change occurs. can get. The slow axis direction of the retardation layer 38 and the transmission axis of the first polarizing plate 41 are 67.5 degrees and 90 degrees, respectively, with respect to the alignment direction of the liquid crystal layer.

  Further, since the retardation of the liquid crystal layer 10 and the retardation layer 38 of the reflective display unit is set to a quarter wavelength and a half wavelength, respectively, in the reflective display unit, the liquid crystal layer 10, the retardation layer 38, and the first retardation layer 38. The laminated body of the polarizing plates 41 becomes a broadband circularly polarizing plate. When no voltage is applied, the incident light is incident on the reflecting plate in a circularly polarized state or a polarization state close thereto in almost the entire visible wavelength range. When the light enters the first polarizing plate 41 again after reflection, the direction of vibration becomes linearly polarized light parallel to the absorption axis of the first polarizing plate, so that an achromatic dark display is obtained.

The expression (1) for determining the slow axis azimuth angle θ _PH of the retardation layer 38 and the retardation of the retardation layer 38 and the liquid crystal layer 10 are derived as follows using Poincare sphere display.

2θ _PH = ± 45 ° + θ _LC (1)
(Θ _LC : Azimuth angle of alignment direction of liquid crystal layer)
The Poincare sphere display is defined in a space having three axes of Stokes parameters (S1, S2, S3) describing the polarization state, and each point on the Poincare sphere corresponds to the polarization state on a one-to-one basis. For example, the intersection line (equator) with the (S1, S2) plane on the Poincare sphere corresponds to linearly polarized light, the intersection with the S3 axis (north and south poles) corresponds to circularly polarized light, and the rest corresponds to elliptically polarized light. To do. Further, (S1, S2, S3) are expressed by the following equations (2), (3), and (4) using an arbitrary X-axis component Ex and an arbitrary Y-axis component Ey of the electric vector, and the phase difference δ between Ex and Ey, respectively. expressed.

S1 = (Ex ² −Ey ² ) / (Ex ² + Ey ² ) (2)
S2 = 2ExEycos δ / (Ex ² + Ey ² ) (3)
S3 = 2ExEysinδ / (Ex ² + Ey ² ) (4)
The conversion of the polarization state by the phase difference layer or the liquid crystal layer without shake is included in the (S1, S2) plane on the Poincare sphere, and is expressed as a rotation around a line passing through the center of the Poincare sphere. The rotation angle at this time is 1/2 rotation if the retardation of the phase plate is 1/2 wavelength, and 1/4 rotation if the retardation is 1/4 wavelength.

  Incident light having a representative wavelength in the visible light region, for example, a wavelength of 550 nm at which human visibility is maximized, sequentially passes through the first polarizing plate 41, the retardation layer 38, and the liquid crystal layer 10 of the reflective display unit. Then, attention is paid to the process of reaching the pixel electrode 28 or the common electrode 29.

  For the sake of explanation, if the Poincare sphere is simulated as a globe and the intersection with the S3 axis is called the north and south poles, and the intersection with the (S1, S2) plane is called the equator, the first polarizing plate 41 converts it into linearly polarized light. The incident light is located at the equator on the Poincare sphere, but the phase difference layer 38 causes the azimuth angle to make a half rotation about the rotation axis and move to another point on the equator, so that the linearly polarized light having a different vibration direction is obtained. Is converted to Next, the liquid crystal layer 10 rotates the azimuth by a quarter around the rotation axis and moves to the north pole, that is, is converted into circularly polarized light.

  Next, when attention is paid to incident light having a wavelength other than this, retardation has a wavelength dependency, and the retardation is larger on the shorter wavelength side and smaller on the longer wavelength side in both the retardation layer and the Yoketsu layer. Therefore, the rotation angle varies depending on the wavelength, and light having a wavelength other than 550 nm moves to a point deviating from the equator without being halved in rotation by the retardation layer 38. Since the retardation of blue light on the short wavelength side is larger than ½ wavelength, it moves more than ½ rotation and moves to a position off the equator. Since the red light on the long wavelength side has a retardation smaller than ½ wavelength, the red light rotates smaller than ½ rotation and moves to a position off the equator.

However, since the movement direction is substantially opposite in the rotation by the liquid crystal layer 10 that acts next, the difference in the rotation angle due to the wavelength generated in the retardation layer 38 is compensated. That is, the blue light on the short wavelength side rotates more than ¼ rotation in the liquid crystal layer 10, but reaches just above the north pole because it starts moving from the southern hemisphere. The red light on the long wavelength side rotates in the liquid crystal layer 10 less than 1/4 rotation, but since it starts to move from above the northern hemisphere, it reaches just above the North Pole by rotating less than 1/4 rotation. As a result, light of each wavelength is concentrated in the vicinity of the North Pole, and light of each wavelength becomes substantially the same circularly polarized light. When this is observed as a display state of the liquid crystal layer, an achromatic dark display having a reduced reflectance in a wide visible wavelength region can be obtained.
When an auxiliary line is drawn so as to extend the ¼ rotation direction, the auxiliary line is orthogonal to the liquid crystal layer alignment direction (azimuth angle θ ′ _LC ) representing the center of the rotation. Further, the slow axis direction (azimuth angle θ ′ _PH ) of the built-in phase plate representing the center of 1/2 rotation bisects the angle between the S1 axis and the auxiliary line. The angle tangent obtained by dividing the angle between the Sl axis and the auxiliary line into two equal parts, θ ′ _PH −180 °, and θ ′ _LC −180 ° is equal to (θ ′ _PH −180 °) × 2 + 90 °. The following equation (5) is obtained.

2θ ′ _PH = 90 ° + θ ′ _LC (5)
In the above, incident light of each wavelength is concentrated on the North Pole NP on the Poincare sphere, but the same effect can be obtained by concentrating on the South Pole SP of the Poincare sphere. In this case, the relationship between θ ′ _PH and θ ′ _LC is expressed by the following equation (6).

2θ ′ _PH = −90 ° + θ ′ _LC (6)
Furthermore, in order to concentrate the incident light of each wavelength on the north pole NP or the south pole SP, the relationship between θ _PH and θ ′ _LC is expressed by equations (5) and (6), respectively. That is, since 360 ° −θ ′ _LC is equal to (360 ° −θ ′ _PH ) × 2 + 90 °, 2θ ′ _PH = 360 ° + 90 ° + θ ′ _LC , which is expressed by the equation (5). Since 180 ° −θ ′ _LC is equal to (180 ° −θ ′ _PH ) × 2 + 90 °, 2θ ′ _PH = 360 ° −90 ° + θ ′ _LC , which is expressed by Expression (6).

The rotation axis on the Poincare sphere corresponds to the azimuth angles θ _PH and θ _LC of the slow axis, and the azimuth angle of the rotation axis is twice the azimuth angle of the slow axis in real space (θ ′ _PH = 2θ _PH , θ ′ _LC = 2θ _LC ). By substituting this into the equations (5) and (6), the above-described equation (1) representing the relationship between the slow axis azimuth of the built-in phase plate and the liquid crystal layer can be obtained.

In this embodiment, in order to make the viewing angle characteristic of transmissive display equal to that of transmissive IPS, the arrangement of polarizing plates in the transmissive display unit is made the same as that of the transmissive IPS system. This made θ _LC = 90 degrees. By substituting this into equation (1) and selecting a minus sign, θ _PH = 22.5 degrees, and the slow axis azimuth of the retardation layer is obtained. Note that details regarding the setting of the slow axis azimuth of the retardation layer described above are disclosed in Patent Document 3 and will not be described further.

The liquid crystal panel produced as described above was connected to a driving device, a backlight was placed behind the liquid crystal display device, and the display state was observed. When observed in a bright place with the backlight turned off, a display image by reflection display could be confirmed. Next, when the backlight was turned on and observed in a dark place, a display image by transmissive display could be confirmed. Even if the observation direction with respect to the substrate normal is changed in a wide range, gradation inversion does not occur, and the phase difference value Δn of the transparent portion in the transmissive display portion becomes 0.0001 or less, and no residual phase difference is recognized. Therefore, no decrease in contrast ratio was observed.
In this embodiment mode, an IPS liquid crystal display device has been described. However, a similar effect can be obtained by forming a retardation plate on a color filter substrate in the VA mode and the TN mode.

<Comparative example>
Next, in order to clarify the effectiveness of the present invention, two comparative examples will be described.

  4 is a cross-sectional view of a liquid crystal panel according to Comparative Example 1 (corresponding to a cross-sectional view in the A-A ′ direction of FIG. 1).

  This comparative example is different from the above embodiment in that the alignment layer 37 ′ for the retardation layer is formed not only in the reflective display area RA but also in the transmissive display area TA. Moreover, in this comparative example, the transparent layer 38n which exists in the said embodiment does not exist.

  FIG. 5 shows a manufacturing process of the liquid crystal panel according to this comparative example.

  First, an alignment film (third alignment film) 37 ′ for a retardation layer, which is a polyimide material, is formed on the entire surface of the first substrate 31 on the first protective film 36, and then rubbed to perform alignment control ability. (P-2). The polyimide material here does not need to be photosensitive, and for example, the San-Ever series made by Nissan Chemical can be used. Further, the third alignment film 37 ′ is horizontally aligned and has a function of determining the slow axis direction of the retardation layer 38.

  A position made of an organic material in which a polymerization initiator (photoreaction initiator) is dispersed in an organic solvent on a nematic liquid crystal monomer having a photoreactive acrylic group (acrylate) at the molecular end on the third alignment film 37 ′. A phase difference layer material is applied (P-3). Examples of the liquid crystal monomer with acrylate, the polymerization initiator, and the organic solvent are as described above. After applying the retardation layer material, this is pre-baked for 2 to 3 minutes with a hot plate at 100 ° C. to remove the solvent, thereby forming a transparent film (P-4).

  This film is oriented in the direction of the orientation treatment of the third orientation film 37 ′ when pre-baked, and has a function as the retardation layer 38.

  For the pre-baked retardation layer material, using an exposure mask with openings corresponding to the pattern of the retardation layer, the portion corresponding to the reflective display portion is irradiated with ultraviolet light, and the acrylic group is photopolymerized and cured. The retardation layer 38 is designated (P-5). By this mask exposure, the acrylate corresponding to the opening of the exposure mask is polymerized to function as the retardation film 38. At this time, the film concentration is adjusted by appropriately adjusting the solution concentration and the coating conditions at the time of coating so that the retardation of the retardation layer 38 becomes a half wavelength at a wavelength of 550 nm. Thereafter, development with an organic solvent is performed to remove unexposed portions (P-6).

  In this comparative example, since the alignment film 37 ′ for the retardation layer is applied on the entire surface, the alignment film 37 ′ for the retardation layer remains in the transmissive display portion TA. The polyimide material is strongly colored (yellow), and the transmittance in the visible light region is inevitably lowered even as a thin film. Further, by using the photosensitive polyimide material as in the above embodiment, the alignment film of the transmissive display portion TA can be removed, and it is possible to avoid a decrease in the transmittance of the transmissive display portion TA. In addition, two steps of a photo process are required for the patterning of the photosensitive polyimide and the patterning of the retardation layer, and an increase in cost cannot be avoided.

  Next, a transparent organic layer is applied on the retardation layer 38 to form the second protective film 40 (P-7). The subsequent steps are the same as in the above embodiment.

  The liquid crystal panel of Comparative Example 1 produced as described above was connected to a driving device, a backlight was placed behind the liquid crystal display device, and the display state was observed. When observed in a bright place with the backlight turned off, a display image by reflection display could be confirmed. Next, when the backlight was turned on and observed in a dark place, a display image by transmissive display could be confirmed. Even if the observation direction with respect to the substrate normal was changed in a wide range, gradation inversion did not occur. However, since there were more (as many as the third alignment film) than the transmission type panel of the same configuration, coloring by the alignment film was confirmed.

  Next, Comparative Example 2 will be described.

  6 shows a cross-sectional view of a liquid crystal panel according to Comparative Example 2 (corresponding to a cross-sectional view in the A-A ′ direction of FIG. 1).

  This comparative example is different from the above embodiment in that the alignment layer 37 ′ for the retardation layer is formed not only in the reflective display area RA but also in the transmissive display area TA. On the other hand, in this comparative example, the transparent layer 38n which exists in the said embodiment exists.

  FIG. 7 shows a manufacturing process of the liquid crystal panel according to this comparative example.

  First, an alignment film (third alignment film) 37 ′ for a retardation layer, which is a polyimide material, is formed on the entire surface of the first substrate 31 on the first protective film 36, and then rubbed to perform alignment control ability. (P-2). The polyimide material here does not need to be photosensitive, and for example, the Sanver series manufactured by Nissan Chemical Co., Ltd. can be used. Further, the third alignment film 37 ′ is horizontally aligned and has a function of determining the slow axis direction of the retardation layer 38.

  An organic material in which a polymerization initiator (reaction initiator) having a phosphine oxide structure is dispersed in an organic solvent on a nematic liquid crystal monomer having a photoreactive acrylic group (acrylate) at the molecular end on the third alignment film 37 A retardation layer material made of is applied (P-3). Examples of the liquid crystal monomer with acrylate, the polymerization initiator, and the organic solvent are as described above.

  After applying the retardation layer material, this is pre-baked for 2 to 3 minutes with a hot plate at 100 ° C. to remove the solvent, thereby forming a transparent film (P-4). This film is oriented in the direction of the orientation treatment of the third orientation film 37 ′ when pre-baked, and has a function as the retardation layer 38.

  The pre-baked retardation layer material is irradiated with ultraviolet light on the portion corresponding to the reflective display portion RA using an exposure mask having an opening corresponding to the pattern of the retardation layer 38 to photopolymerize the acrylic group. It hardens | cures and it is set as the phase difference layer 38 (P-5). By this mask exposure, the acrylate corresponding to the opening of the exposure mask is polymerized and functions as a retardation plate. At this time, the film concentration is adjusted by appropriately adjusting the solution concentration and the coating conditions at the time of coating so that the retardation of the retardation layer 38 becomes a half wavelength at a wavelength of 550 nm. Thereafter, the entire first substrate is heated to a temperature equal to or higher than the nematic / isotropic phase transition temperature of the nematic liquid crystal having an acrylate at the molecular end, so that an uncured retardation layer material corresponding to the non-opening portion of the exposure mask is obtained. It is assumed to be the first layer. By exposing the entire surface in a heated state while maintaining the isotropic layer, the uncured acrylic group located at the non-opening portion of the exposure mask is photopolymerized and cured as the isotropic layer, thereby forming a transparent layer 38n. (P-6).

  In this comparative example, since the alignment film 37 ′ for the retardation layer is applied on the entire surface, the alignment film 37 ′ for the retardation layer remains in the transmissive display area RA. The polyimide material is strongly colored (yellow), and the transmittance in the visible light region is inevitably lowered even as a thin film. Further, like the embodiment of the present invention, by using a photosensitive polyimide material, the alignment film of the transmissive display portion can be removed, and it is possible to avoid a decrease in the transmittance of the transmissive display portion, In this case, two steps of the photo process are required for patterning of the photosensitive polyimide and patterning of the retardation layer, and thus an increase in cost cannot be avoided.

Next, a transparent organic layer is applied on the retardation layer 38 and the transparent layer 38n to form the second protective film 40 (P-7). The subsequent steps are the same as in the above embodiment.
The liquid crystal panel of Comparative Example 2 produced as described above was connected to a driving device, a backlight was placed behind the liquid crystal display device, and the display state was observed. When observed in a bright place with the backlight turned off, a display image by reflection display could be confirmed. Next, when the backlight was turned on and observed in a dark place, a display image by transmissive display could be confirmed. Even if the observation direction with respect to the substrate normal was changed in a wide range, gradation inversion did not occur. However, since there were more (as many as the third alignment film) than the transmission type panel of the same configuration, coloring by the alignment film was confirmed. Further, Δn of the transparent portion in the transmissive display portion was 0.00007, and a decrease in contrast due to a residual phase difference remaining in a minute amount was recognized.

It is a top view explaining the structural example of 1 pixel of a liquid crystal panel. It is sectional drawing along the A-A 'line of FIG. It is explanatory drawing of the manufacturing process of a liquid crystal panel. 6 is a sectional view of a liquid crystal panel of Comparative Example 1. 10 is an explanatory diagram of a manufacturing process of the liquid crystal panel of Comparative Example 1. FIG. 10 is a cross-sectional view of a liquid crystal panel of Comparative Example 2. FIG. 10 is an explanatory diagram of a manufacturing process of a liquid crystal panel of Comparative Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal layer 21 ... Scanning wiring 22 ... Signal wiring 23 ... Common wiring 25 ... Amorphous silicon layer 26 ... Through hole 27 ... Through hole 28 ... Pixel electrode 29 ... Common electrode 30 ... Slit 31 ... First substrate (color filter substrate)
32 ... Second substrate (TFT substrate)
33 ... 1st alignment film 34 ... 2nd alignment film 35 ... Black matrix 36 ... Planarization layer (1st protective film)
37 ... third alignment film 38 ... retardation layer 38n ... transparent layer 39 ... film thickness adjusting layer 40 ... second protective film 41 ... first polarizing plate 42- .... Second polarizing plate 43 ... Adhesive layers 51, 52, 53 ... Insulating layer 61 ... Transmitted light 62 ... Reflected light

Claims (12)

A liquid crystal layer is sandwiched between the first substrate and the second substrate facing each other, and both a reflective display portion and a transmissive display portion are provided. A color filter layer is formed on the first substrate, and corresponds to the reflective display portion. A liquid crystal display device including a retardation plate on the liquid crystal layer side of the first substrate,
A planarization layer for planarizing the color filter layer of the first substrate;
An underlayer provided in contact with the planarization layer of the reflective display unit and not provided in the transmissive display unit;
The includes a reflective display portion and the transmissive over the display unit the first substrate the liquid crystal layer side the underlying layer and the resin layer formed on the planarizing layer of a,
In the reflective display unit, the resin layer is oriented by the base layer and functions as a retardation plate,
In the transmissive display section, the resin layer by the underlying layer is not to function as an optically transparent layer is not oriented
A liquid crystal display device comprising a call. The liquid crystal display device according to claim 1, wherein the underlayer is made of a photosensitive polyimide composition. 2. The liquid crystal according to claim 1, wherein the underlayer has a composition mainly composed of a liquid crystalline monomer having an acrylate crosslinking group and a polymerization initiator, and functions as a retardation plate by the composition. Display device. The liquid crystal display device according to claim 1, wherein the resin layer has a residual retardation value Δn of 0.0001 or less in the transmissive display unit. 2. The liquid crystal display device according to claim 1, wherein the resin layer has a light transmittance of 90% or more in a wavelength range of 400 nm to 800 nm in the transmissive display unit. The liquid crystal display device according to claim 1, wherein the resin layer has a light transmittance of 90% or more in a visible light region in the reflective display unit. In a manufacturing method of a liquid crystal display device in which a liquid crystal layer is sandwiched between a first substrate and a second substrate facing each other, a reflection display unit and a transmission display unit are combined, and a retardation plate is built in the reflection display unit.
The underlayer, an underlayer forming step you selectively formed in the reflective display portion not formed on the transmissive display section,
Rubbing the formed underlayer, and
Applying a composition mainly composed of a liquid crystalline monomer having an acrylate crosslinking group and a polymerization initiator over the reflective display portion and the transmissive display portion including the rubbing-treated underlayer ;
The coated composition is heated at a temperature higher than the melting point of the liquid crystalline monomer and lower than the nematic / isotropic phase transition temperature of the liquid crystalline monomer, and exposed to the reflective display portion and the transmissive display portion. has, and as engineering which Ru is crosslinked curing the composition,
In the cross-linking and curing step, the reflective display portion forms the retardation plate by orienting the composition by the underlayer, and the transmissive display portion does not orient the composition due to the absence of the underlayer. To form an optically transparent layer
Method of manufacturing a liquid crystal display device comprising a call. A liquid crystal layer is sandwiched between the first substrate and the second substrate facing each other, and both a reflective display portion and a transmissive display portion are provided. A color filter layer is formed on the first substrate, and corresponds to the reflective display portion. In the method of manufacturing a liquid crystal display device including a retardation plate on the liquid crystal layer side of the first substrate,
Forming a flattening layer for flattening the color filter layer of the first substrate containing the retardation plate with a transparent resin;
Applying a photocurable resin composition to be a base layer of the retardation plate to the planarizing layer;
Wherein the curing process of the resin composition of the reflective display part is cured Ri by the mask exposure and development process of removing the uncured portion of the resin composition was not cured of the transmissive display section, the base layer, the transmission Selectively forming the reflective display unit without forming the display unit ;
Applying a composition mainly composed of a liquid crystalline monomer having an acrylate crosslinking group and a polymerization initiator over the reflective display portion and the transmissive display portion including the formed underlayer, and
In the cross-linking and curing step, the reflective display portion forms the retardation plate by orienting the composition by the underlayer, and the transmissive display portion does not orient the composition due to the absence of the underlayer. To form an optically transparent layer
Method of manufacturing a liquid crystal display device comprising a call. The underlayer, The method according to claim 7 or 8, characterized in that it is formed from a photosensitive polyimide composition. Wherein the optically transparent layer, The method according to claim 7 or 8 residual retardation value Δn is equal to or is 0.0001 or less. The method for manufacturing a liquid crystal display device according to claim 7 or 8 , wherein the optically transparent layer has a light transmittance of 90% or more in a wavelength range of 400 nm to 800 nm. The retardation plate manufacturing method of the liquid crystal display device according to claim 7 or 8 light transmittance is equal to or less than 90% in the visible light region.

Images