JP2002107724A - Semitransmission type liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both of high-quality reflection display and high-quality transmission display in a semitransmission type liquid crystal display device having a reflection display region and a transmission display region and to obtain the above liquid crystal display device in an easy manufacture process. SOLUTION: In the semitransmission type liquid crystal display device 100A having a reflection display region R and a transmission display region T in the display region, a λ/4 birefringent layer 15 is formed between a reflection layer 16 and a liquid crystal layer 12, and the layer thickness of the liquid crystal layer 12 is made same both in the reflection display region R and the transmission display region T.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transflective liquid crystal display device having a reflective display area and a transmissive display area, wherein the thickness of the liquid crystal layer is equal in the reflective display area and the transmissive display area. .

[0002]

2. Description of the Related Art A liquid crystal display device is characterized in that it is lightweight, thin and consumes low power, and is used as a display device for a portable information terminal (PDA).

In order to use a liquid crystal display device as a display device for a PDA, display performance that is lightweight, thin, consumes low power, and has high visibility in any environment is required.

Incidentally, a conventional transmission type liquid crystal display device is
Because of the backlight, it is very easy to see when the surroundings are dark, but on the other hand, there is a disadvantage that it becomes almost invisible under very strong external light such as sunlight. Conversely, the reflective liquid crystal display device has a drawback that it is easy to see when the surroundings are bright, but is almost invisible when the surroundings are dark.

In order to solve the problems of the transmission type liquid crystal display device and the reflection type liquid crystal display device, Japanese Patent Laid-Open No. 7-3 is disclosed.
In JP-A-33598 and the like, a transflective display that transmits a part of the backlight and reflects a part of the ambient light is used, so that both the transmissive display and the reflective display can be performed by one liquid crystal display device. The technology to be realized is disclosed.

In Japanese Patent Application Laid-Open No. 11-316382, a high-reflectance region and a high-transmission efficiency region are provided in a display pixel to display both a transmission type display and a reflection type display with high quality. Techniques are disclosed. FIG. 8 is a layer configuration diagram of a liquid crystal panel of such a liquid crystal display device. As shown, the driving substrate 10 of the liquid crystal panel includes a transmissive display region T in which a transparent electrode 2a and an alignment film 3a are sequentially stacked on a transparent substrate 1 on which switching elements are formed.
The interlayer insulating film 4, the reflective electrode 5, and the alignment film 3 are formed on the extension region of the transparent electrode 2 a formed in the transmissive display region T.
a is composed of a reflective display region R that is sequentially laminated, and a step is formed at the boundary between the reflective display region R and the transmissive display region T. On the other hand, the counter substrate 11 is formed by sequentially laminating a color filter 7, a transparent electrode 2b, and an alignment film 3b on a transparent substrate 6. A liquid crystal layer 12 is sandwiched between the driving substrate 10 and the counter substrate 11, and A cell is configured. A polarizing plate 1 is provided on the surface of the drive substrate 10 opposite to the liquid crystal cell.
A λ / 4 retardation plate 13 and a polarizing plate 14b are sequentially laminated on a surface of the opposite substrate 11 opposite to the liquid crystal cell.

[0007]

Problems to be Solved by the Invention Japanese Patent Laid-Open No. 7-33359
In the case of the structure as disclosed in Japanese Patent Application Laid-Open No. 8 (1999) -1995, internal absorption or scattering of incident light occurs in the semi-transmissive film, so that there is a problem that light utilization efficiency is poor. In addition, because of the structure, the retardation design of each of the transmissive display area and the reflective display area cannot be performed, so that it is difficult to achieve both display quality of transmission and reflection.

On the other hand, in Japanese Patent Application Laid-Open No. 11-316382, a reflective display region R having a high reflectance and a transmissive display region T having a high transmittance are provided independently in a pixel. Is high, and the retardation design can be performed individually. However, in this structure, the optimal retardation of the reflective display region R is λ / 4, and the transmissive display region T
Since the optimum retardation is λ / 2, in order to realize this, the thickness of the liquid crystal layer in the reflective display region R and the height of the step between the reflective display region R and the transmissive display region T are made equal. This necessitates a large step structure having a thickness of several μm in the liquid crystal cell. This complicates the manufacturing process of the electrode contact and the like, and causes problems such as alignment defects, light leakage, and reduced display uniformity at the steps.

In addition, while the optimum retardation for a transmissive liquid crystal display device is λ / 2, the optimum retardation for reflective display is λ / 4 in any of the above-mentioned technologies. Must be １ ／ of the thickness of the transmissive liquid crystal display device. However, when the thickness of the liquid crystal cell is reduced, short-circuits are likely to occur between the upper and lower substrates sandwiching the liquid crystal layer, and it is difficult to maintain uniform cell thickness. Conversely, when the thickness of the liquid crystal cell is increased, in a structure as disclosed in JP-A-11-316382, a step in the liquid crystal cell becomes high,
The above-mentioned problem occurs.

[0010] In both the structure as in JP-A-7-333598 and the structure as in JP-A-11-316382, it is necessary to provide a λ / 4 retardation plate 13 above the liquid crystal cell. In order to achieve the condition of λ / 4 in a wide wavelength region, a plurality of retardation plates are stacked. For this reason, there arise problems such as parallax in display, a narrow viewing angle, a long manufacturing process, and high cost.

In order to solve the above-mentioned conventional problems, the present invention provides a single liquid crystal display device capable of obtaining both a high-quality reflective display and a high-quality transmissive display. Is realized by a simple manufacturing process.

[0012]

SUMMARY OF THE INVENTION The present inventor has proposed a semi-transmissive liquid crystal display device having a reflective display area and a transmissive display area in a display area. Λ / 4 in the liquid crystal cell instead of the 4 phase plate
It has been found that when the birefringent layer is provided, the optimum retardation of the liquid crystal layer in the reflective display region and the liquid crystal layer in the transmissive display region can be made equal to each other, so that it is not necessary to form a step in the liquid crystal cell.

That is, the present invention relates to a transflective liquid crystal display device having a reflective display region and a transmissive display region in a display region, wherein the first substrate has a reflective layer in the reflective display region, and is opposed to the first substrate. Substrate, a liquid crystal layer sandwiched between the two substrates, and a λ / 4 provided between the reflective layer and the second substrate.
A transflective liquid crystal display device comprising a λ / 4 birefringent layer showing a retardation of (λ is the wavelength of visible light), wherein the thickness of the liquid crystal layer in the reflective display area is equal to the thickness of the liquid crystal layer in the transmissive display area. I do.

According to the present invention, a reflective layer is formed in a reflective display area of a first substrate, the first substrate and the second substrate are opposed to each other, and a liquid crystal is sandwiched between the two substrates. A method for manufacturing a transflective liquid crystal display device having a reflective display region and a transmissive display region in a display region, wherein a λ / 4 (λ is a wavelength of visible light) light on a first substrate after a reflective layer is formed. A method of manufacturing a transflective liquid crystal display device in which a λ / 4 birefringent layer exhibiting retardation is formed by applying a liquid crystal polymer, and the layer thickness of the liquid crystal layer in the reflective display region is made equal to the layer thickness of the liquid crystal layer in the transmissive display region provide.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. In each drawing, the same reference numerals represent the same or equivalent components.

FIG. 1 shows a liquid crystal display device according to an example of the present invention.
FIG. 2 is a schematic sectional view of a pixel.

The driving substrate 10 of the liquid crystal display device 100A
Is a reflective display region R in which a reflective layer 16 is provided on a transparent substrate 1 (first substrate) on which switching elements are formed.
And the transmissive display area T without the reflective layer 16.
On the reflective layer 16 (on the transparent substrate 1 in the transmissive display area T), a λ / 4 birefringent layer 15, a transparent electrode 2a, and an alignment film 3a are sequentially laminated.

On the other hand, the opposing substrate 1 opposing the driving substrate 10
Reference numeral 1 denotes a transparent substrate (second substrate) 6 in which a color filter 7, a transparent electrode 2b, a light scattering film 17, and an alignment film 3b are sequentially laminated. A liquid crystal layer 12 is sandwiched between the liquid crystal layers to form a liquid crystal cell. Polarizing plates 14a and 14b are provided on the driving substrate 10 and the opposing substrate 11 outside the liquid crystal cell, respectively.

In the liquid crystal display device 100A, although the reflective display region R and the transmissive display region T are distinguished by the presence or absence of the reflective layer 16, the thickness of the liquid crystal layer 12 is
It is characteristic that the reflection display area R and the transmission display area T are equal.

Here, it is preferable that the liquid crystal layer 12 has a retardation of λ / 2 (λ is the wavelength of visible light). This is generally expressed by the relational expression (1) between the transmittance and the thickness of the liquid crystal layer in transmissive display.

T = sin ² (Δnd · π / λ) (1) (where T: transmittance Δn: birefringence of liquid crystal d: thickness of liquid crystal layer λ: wavelength of light) , Δnd = λ / 2.

In the liquid crystal display device 100A, as described above, the layer thickness of the liquid crystal layer 12 in the reflective display region R and the layer thickness of the liquid crystal layer 12 in the transmissive display region T are equal to each other. This is because the λ / 4 birefringent layer 15 is provided between the transparent electrode 2a and the transparent electrode 2a. That is, the liquid crystal layer 12
Are in the alignment state as shown in FIG. 2, in the reflective display region R, the linearly polarized light transmitted through the polarizing plate
Is rotated by 2θ with respect to the original polarization axis.
Next, this linearly polarized light enters the λ / 4 birefringent layer 15 and becomes circularly polarized light, which is reflected by the reflection layer 16 to become reverse circularly polarized light, and again becomes linearly polarized light and becomes λ / 4 birefringent. Tier 1
5 is emitted. At this time, if the angle の between the optical axis of the λ / 4 birefringent layer 15 and the polarization axis of the polarizing plate 14b has the relationship of Θ = 2θ + nπ (where n = 0, 1, 2,...), The axis of the linearly polarized light emitted from the / 4 birefringent layer 15 is equal to that at the time of incidence. Thereafter, the axis of the linearly polarized light is rotated by −2θ by transmitting through the liquid crystal layer 12 again. Therefore, the axis of the linearly polarized light transmitted through the liquid crystal layer 12 coincides with the axis of the polarizing plate 12b, and the light is
b, and a bright display is obtained.

On the other hand, in the transmissive display area T, the linearly polarized light is
After passing through the λ / 4 birefringent layer 15, it becomes circularly polarized light and exits downward. However, by providing a λ / 4 birefringent layer between the polarizing plate 14 a and the λ / 4 birefringent layer, the light can be converted into linearly polarized light. Bright display is achieved by matching the axis of the linearly polarized light with the polarization axis of the polarizing plate 14a.

Therefore, it is possible to make the retardation of the liquid crystal layers in the reflective display region R and the transmissive display region T both λ / 2, that is, to make the thicknesses of both liquid crystal layers equal.

More specifically, for example, when no electric field is applied to the liquid crystal layer 12, Θ = π / 4, θ = π / 8, n
If = 0, the brightest state is set. On the other hand, when an electric field is applied to the liquid crystal layer 12 to switch the liquid crystal and the liquid crystal becomes vertical to the substrate interface, the liquid crystal layer 12 is in the darkest state. Therefore, high-contrast display can be performed in the normally white mode.

Further, the liquid crystal may be oriented vertically to the substrate interface in a state where no voltage is applied to the liquid crystal layer 12. In this case, it is sufficient that 、 = π / 4 and θ = π / 8 are satisfied when a voltage is applied to the liquid crystal layer 12, whereby a high-contrast display can be performed in a normally black mode. Becomes

When Θ = 2θ + nπ is satisfied, both the retardation of the liquid crystal layer in the reflective display region R and the retardation of the liquid crystal layer in the transmissive display region T can be set to λ / 2, and a display with high contrast can be obtained. However, even when Θ = 2θ + nπ is not strictly satisfied, a display with a considerable contrast can be obtained.

As described above, the liquid crystal display device 100A
In this case, the thickness of the liquid crystal layer in the reflective display region R and the thickness of the liquid crystal layer in the transmissive display region T are equal, so that there is no problem associated with a step between the reflective display region R and the transmissive display region T as in the conventional transflective liquid crystal device. Further, by providing the λ / 4 birefringent layer 15 between the reflective layer 16 and the transparent electrode 2a, the λ /
Since the phase difference plate of No. 4 is not provided, the problem of parallax and viewing angle does not arise as in the conventional liquid crystal display device (FIG. 8) in which the λ / 4 phase difference plate 13 is provided above the liquid crystal cell. . Further, the step of attaching a film as a λ / 4 retardation plate on the liquid crystal cell can be omitted, and the manufacturing cost can be reduced. Further, in the liquid crystal display device 100A, since the λ / 4 birefringent layer 15 is provided on the entire surface of the substrate 1, it can be easily manufactured.

The λ / 4 birefringent layer 15 used in the liquid crystal display device 100A can be formed using a light or thermosetting liquid crystal polymer. That is, a photocurable or thermosetting liquid crystal polymer dissolved in a solvent is applied on a substrate that has been subjected to an alignment treatment by a rubbing method or a photo alignment method, and the solvent is evaporated.
As a result, the liquid crystal is uniaxially aligned on the alignment-treated substrate.
In this state, the liquid crystal polymer is cured by irradiating light such as ultraviolet rays or heat treatment to form a birefringent layer. In order to control the retardation of the birefringent layer to λ / 4, the coating thickness of the liquid crystal polymer is appropriately adjusted. More specifically,
For example, RMM34 manufactured by Merk (Δn = 0.145,
When (λ = 589 nm) is used, the liquid crystal polymer is diluted with toluene as a solvent, and is applied onto an alignment-treated substrate. Thereafter, the wavelength is 360 nm, and the intensity is 10 mW / cm.
^The birefringent layer is formed by irradiating ultraviolet light of No. 2 and heating at 100 ° C. for 1 hour. In this birefringent layer, by setting the coating thickness to 1 μm, a retardation of λ / 4 is obtained (λ = 589 nm).

The λ / 4 birefringent layer 15 is preferably formed from a plurality of λ / 4 birefringent layers having different retardation wavelength characteristics. Generally, since the birefringence value of the λ / 4 birefringent layer has wavelength dependence, the λ / 4
Although a retardation of / 4 cannot be obtained, it is possible to obtain a retardation of λ / 4 in a wide wavelength region by laminating a plurality of layers having different wavelength characteristics of the retardation. The thickness of the λ / 4 retardation plate conventionally provided on the upper part of the liquid crystal cell has a film thickness of 1 μm.
Since the thickness of the layer is about 0.1 mm, the lamination of a plurality of the layers has a great effect on the parallax and the viewing angle.
Since the thickness of one layer of the / 4 birefringent layer 15 is about 1 μm, even if a plurality of layers are stacked, the thickness is only several μm, and does not affect the parallax or the viewing angle. In addition, the cost required for lamination is lower when a plurality of films are applied and the liquid crystal polymer is applied a plurality of times.

In the liquid crystal display device 100A shown in FIG.
Except for the formation of the / 4 birefringent layer 15, it can be manufactured according to a known method of manufacturing a transflective liquid crystal display device having a transmissive display area and a reflective display area in the display area. For example, as the liquid crystal layer 12, either a horizontal alignment liquid crystal or a vertical alignment liquid crystal can be used. Nematic liquid crystals and smectic liquid crystals can be used. In the case of smectic liquid crystal, switching angle (angle θ in Fig. 2)
Is preferably π / 8.

As the transparent substrate 1 forming the driving substrate 10 or the transparent substrate 6 forming the counter substrate 11, a glass substrate or a plastic substrate can be used.

The transparent electrodes 2a and 2b can be formed from a transparent conductive film such as ITO.

As the alignment films 3a and 3b, those obtained by using polyimide, polyamide or the like as an alignment film material and performing an alignment treatment by a rubbing method, a photo alignment method or the like can be used.

As a method of manufacturing the liquid crystal display device 100A of FIG. 1, first, Al, Ag, Al alloy, A
A reflective layer 16 is formed by depositing a metal having a high reflectivity such as g alloy by sputtering or the like, and patterning the film in accordance with the shape of the reflective display region R. The transparent electrode 2a is formed by forming the λ / 4 birefringent layer 15 using the liquid crystal polymer in both regions T as described above, further forming ITO by sputtering, and patterning the film into the shape of a pixel electrode. Then, an alignment film 3a is formed thereon by a rubbing method or an optical alignment method,
The driving substrate 10 is obtained.

On the other hand, the color filter 7, the transparent electrode 2b, the light scattering film 17, and the alignment film 3b are sequentially formed on the transparent substrate 6 in a usual manner to obtain the counter substrate 11.

Then, the driving substrate 10 and the opposing substrate 11 are opposed to each other using a spacer so that the cell gap becomes λ / 2, and the liquid crystal layer 12 is sandwiched between the two substrates to form a liquid crystal cell. It is manufactured by providing polarizing plates 14a and 14b outside the substrate 10 and outside the counter substrate 11, respectively. At this time, the transmission axis of the polarizing plate 14b,
It is preferable that the optical axis of the λ / 4 birefringent layer 15 and the optical axis of the liquid crystal layer 12 have the above-mentioned relationship, and the thickness of the liquid crystal layer 12 is made equal between the reflective display region R and the transmissive display region T. .

According to the method of manufacturing the liquid crystal display device 100A, the conventional λ /
Since the λ / 4 birefringent layer 15 is formed by applying a liquid crystal polymer instead of attaching a 4 retardation film or a retardation plate,
It is possible to easily form a birefringent layer that can withstand a high-temperature process such as deposition of ITO performed at the time of manufacturing a liquid crystal cell.

The liquid crystal display device of the present invention can take various modes other than the configuration shown in FIG. For example, in the liquid crystal display device 100A of FIG. 1, the light scattering film 17 is provided on the counter substrate 11 in order to improve the visibility at the time of the reflection display, but as in the liquid crystal display device 100B of FIG. As an alternative, the light-diffusing reflective layer 16x having surface irregularities may be provided, and the light-scattering film 17 may be omitted. The reflection layer 16
May have a function as a pixel electrode in addition to the function as a reflector.

Further, λ / 4 in the height direction of the liquid crystal cell
As long as the formation position of the birefringent layer 15 is between the reflective layer 16 and the liquid crystal layer 12, the optimum value of the thickness of the liquid crystal layer 12 in the reflective display region R and the transmissive display region T can be made equal. Therefore, as shown in FIG. 6, outside the liquid crystal cell (ie,
The λ / 4 birefringent layer 15 may be provided on the surface of the transparent substrate 1 opposite to the liquid crystal layer 12). However, in this case, the reflection layer 1
Since 6 must also be provided outside the liquid crystal cell, it is preferable to provide it in the liquid crystal cell as shown in FIG. 1 from the viewpoint of preventing a decrease in reflectance and the occurrence of parallax.

Further, as shown in FIG. 4, a λ / 4 birefringent layer 15 may be provided between the alignment film 3a and the transparent electrode 2a. However, in order to prevent a decrease in the intensity of the electric field applied from the pixel electrode to the liquid crystal layer 12 and to perform the switching satisfactorily, as shown in FIG.
It is preferable not to provide the λ / 4 birefringent layer 15 thereon.

Further, according to the layer structure of the drive substrate 10 in the reflective display region R of the conventional liquid crystal display device shown in FIG.
When the transparent electrode 2a, the reflective layer 16, and the alignment film 3a are sequentially laminated on the λ / 4 birefringent layer 15, as shown in FIG.
It is preferable to provide between the reflective layer 16 and the alignment film 3a.

On the other hand, λ / 4 in the horizontal direction of the liquid crystal cell
The formation position of the birefringent layer 15 is determined by the liquid crystal display device 100 shown in FIG.
Although it is preferable to form the liquid crystal cell on the entire surface of the transparent substrate 1 as shown in FIG. 4A in order to simplify the manufacturing process of the liquid crystal cell, the liquid crystal cell may not be provided in the transmissive display region T but may be provided only in the reflective display region R. In this case, it is preferable that the driving substrate 10 be flattened so that the thickness of the liquid crystal layer 12 in the reflective display region R and the transmissive display region T is equal. Further, in this case, since the retardation of the transmissive display region T is determined only by the retardation of the liquid crystal layer 12, by making the transmission axes of the upper and lower polarizing plates 14a and 14b orthogonal to each other, a bright and dark display with a good contrast can be obtained at the transmissive display. It is possible to do.

In addition, there is no particular limitation on the position where the color filter is formed, and the color filter may be formed on the drive substrate 10 side. In that case, it is preferable to form it on the reflective layer 16.

The present invention can be applied to both simple matrix type and active matrix type liquid crystal display devices.

[0045]

EXAMPLE 1 A liquid crystal display device having the layer configuration shown in FIG. 1 and having the arrangement shown in FIG. 2 was produced. In this case, horizontal alignment treatment was performed on the upper and lower substrates 1 and 6, respectively, to form a liquid crystal cell having a cell gap of 4 μm, and a nematic liquid crystal (Δn = 0.07) was injected.
The retardation of the λ / 4 birefringent layer 15 is Δnd = 13
7 nm. The angle θ between the transmission axis of the polarizing plate 14b and the optical axis of the liquid crystal layer 12 is π / 8, and the transmission axis of the polarizing plate 14b and λ /
The angle Θ between the four birefringent layers 15 and the optical axis was λ / 4.

FIG. 7 shows the reflection spectrum in this case.
From the figure, the retardation (Δnd) of the liquid crystal layer 12 is λ
It can be seen that the liquid crystal display device of this embodiment used under the condition of / 2 can display bright display and dark display with high contrast.

[0047]

According to the present invention, in a transflective liquid crystal display device having a reflective display area and a transmissive display area, the thicknesses of the liquid crystal layers in the reflective display area and the transmissive display area are equalized. In the liquid crystal display device of the type, a step between the reflective display area and the transmissive display area becomes unnecessary. Therefore, poor orientation around the step due to the step does not occur, and the display quality is improved. In addition, a process for forming the shape of the step and a step for forming the terminal and the wiring of the pixel electrode on the step using the contact hole are not required, so that the manufacturing process of the entire apparatus can be simplified. It is possible to improve reliability and reduce manufacturing costs.

In the present invention, the cell thicknesses of the reflective display region R and the transmissive display region T can both be designed so as to have a retardation of λ / 2, so that they are designed to have a retardation of λ / 4. The cell thickness of the liquid crystal layer 12 in the reflective display region R can be almost doubled as compared with the conventional reflective display region R. Therefore, a short circuit between the upper and lower substrates hardly occurs. In addition, this makes it possible to expand the range of selection of the liquid crystal material used for the liquid crystal layer.

Further, since the λ / 4 phase difference plate conventionally provided on the upper outside of the counter substrate is not required, no parallax is generated by the λ / 4 phase difference plate, and the display angle is not reduced and the display is not performed. The quality is improved. Further, the operation of attaching the λ / 4 phase difference plate is not required, and the process can be simplified.

[Brief description of the drawings]

FIG. 1 is a sectional view of a liquid crystal display device of the present invention.

FIG. 2 is an explanatory diagram of a light transmitting or reflecting state in a reflective display area.

FIG. 3 is a cross-sectional view of the liquid crystal display device of the present invention.

FIG. 4 is a sectional view of a driving substrate of the liquid crystal display device of the present invention.

FIG. 5 is a sectional view of a driving substrate of the liquid crystal display device of the present invention.

FIG. 6 is a sectional view of a driving substrate of the liquid crystal display device of the present invention.

FIG. 7 is a diagram illustrating a relationship between a wavelength and a reflected light intensity in a reflective display region of the liquid crystal display device according to the example.

FIG. 8 is a sectional view of a conventional liquid crystal display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate, 2a, 2b ... Transparent electrode, 3a, 3b
... Orientation film, 4 ... Interlayer insulation film, 5 ... Reflection electrode, 6 ...
Transparent substrate, 7: color filter, 10: drive substrate,
DESCRIPTION OF SYMBOLS 11 ... Opposite board | substrate, 12 ... Liquid crystal layer, 13 ... Phase difference plate, 14 ... Polarizing plate, 15 ... (lambda) / 4 birefringent layer, 16
... Reflection layer, 16x ... Light diffusive reflection layer, 17 ... Light scattering film, 100A, 100B ... Liquid crystal display device of the present invention

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G09F 9/30 349 G09F 9/30 349D 349B F-term (Reference) 2H049 BA02 BA07 BA42 BB03 BB63 BC22 2H091 FA02Y FA08X FA08Z FA11Y FB02 FD07 FD09 FD10 GA01 GA03 KA02 LA12 LA17 5C094 AA43 BA03 BA43 CA19 CA24 DA13 EA04 EA05 EA06 EA07 EB02 ED03 ED11 ED14 ED15 5G435 AA17 BB12 BB15 BB16 DD11 DD13 FF05 GG12KK

Claims (15)

[Claims] 1. A transflective liquid crystal display device having a reflective display area and a transmissive display area in a display area, a first substrate having a reflective layer in the reflective display area, and a second substrate facing the first substrate. A substrate, a liquid crystal layer sandwiched between the two substrates, and a λ / 4 birefringent layer provided between the reflective layer and the second substrate and exhibiting λ / 4 (λ is a wavelength of visible light) retardation. ,
A transflective liquid crystal display device in which the thickness of the liquid crystal layer in the reflective display area is equal to the thickness of the liquid crystal layer in the transmissive display area. 2. A polarizing plate on a second substrate outside a liquid crystal cell, wherein an angle between a transmission axis of the polarizing plate and an optical axis of a liquid crystal layer at the time of brightest display during reflection display is θ, 2. The method according to claim 1, wherein, when an angle between the transmission axis of the polarizing plate and the optical axis of the λ / 4 birefringent layer is Θ, Θ = 2θ + nπ (where n = 0, 1, 2,...). Transflective liquid crystal display. 3. The transflective liquid crystal display device according to claim 1, wherein the liquid crystal layer has a retardation of λ / 2. 4. The transflective liquid crystal display device according to claim 1, wherein the λ / 4 birefringent layer is provided between the reflective layer and the liquid crystal layer. 5. The transflective liquid crystal display device according to claim 4, wherein the λ / 4 birefringent layer is provided between the reflective layer and the transparent electrode on the first substrate. 6. The transflective liquid crystal display device according to claim 1, wherein the λ / 4 birefringent layer is provided on the entire surface of the first substrate. 7. The transflective liquid crystal according to claim 1, wherein the λ / 4 birefringent layer is provided in the reflective display area without being provided in the transmissive display area on the first substrate. Display device. 8. The transflective liquid crystal display device according to claim 1, wherein the λ / 4 birefringent layer comprises a plurality of birefringent layers. 9. A reflective layer is formed in a reflective display area of a first substrate, the first substrate and the second substrate are opposed to each other, and a liquid crystal is sandwiched between the two substrates. A method for manufacturing a transflective liquid crystal display device having a display area and a transmissive display area, wherein a λ / 4 (λ is a wavelength of visible light) retardation on a first substrate after a reflective layer is formed. / 4 A method of manufacturing a transflective liquid crystal display device in which a birefringent layer is formed by applying a liquid crystal polymer, and the layer thickness of the liquid crystal layer in the reflective display region is made equal to the layer thickness of the liquid crystal layer in the transmissive display region. 10. A polarizing plate is provided on a second substrate outside a liquid crystal cell, wherein the angle between the transmission axis of the polarizing plate and the optical axis of the liquid crystal layer at the time of brightest display during reflective display is θ, and the polarization is When the angle between the transmission axis of the plate and the optical axis of the λ / 4 birefringent layer is Θ, the polarizing plate and the liquid crystal are set so that Θ = 2θ + nπ (where n = 0, 1, 2,...) The method for manufacturing a transflective liquid crystal display device according to claim 9, wherein a layer and a λ / 4 birefringent layer are arranged. 11. The method according to claim 9, wherein the retardation of the liquid crystal layer is λ / 2. 12. The method according to claim 9, wherein a reflective layer, a λ / 4 birefringent layer, and a transparent electrode are sequentially formed on the first substrate. 13. The method of manufacturing a transflective liquid crystal display device according to claim 9, wherein the λ / 4 birefringent layer is formed on the entire surface of the first substrate. 14. The transflective liquid crystal display device according to claim 9, wherein the λ / 4 birefringent layer is formed in the reflective display area without being provided in the transmissive display area of the first substrate. Method. 15. The method for manufacturing a transflective liquid crystal display device according to claim 9, wherein a plurality of birefringent layers are formed as the λ / 4 birefringent layer.