JP2003255348A - Liquid crystal display and electronic appliance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display of semi-transmission reflection type which can obtain high contrast display, can suppress the occurrence of disclination near the boundary between a transmission display region and a reflection display region and enables high definition display. <P>SOLUTION: In this liquid crystal display (A), the layer thickness of a liquid crystal layer 3 in the reflection display region (R) is made less than the layer thickness of the liquid crystal layer 3 in the transmission display region (T) and the length of the part where an angle formed with the alignment direction in the substrate surface of the side having an insulation layer 22 is in the range of 0±15° is ≥50% with respect to the total length of the boundary line between the transmission display region (T) and the reflection display region (R). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and an electronic device, and more particularly, it is possible to suppress the occurrence of disclination near the boundary between a transmissive display region and a reflective display region, and realize a high quality display. The present invention relates to a transflective liquid crystal display device that can be used, and an electronic device including the same.

[0002]

2. Description of the Related Art A transflective liquid crystal display device having both a reflective display mode and a transmissive display mode consumes power by switching between a reflective mode display mode and a transmissive mode display mode depending on ambient brightness. It is possible to perform a clear display even when the surroundings are dark while reducing the power.

Such a transflective liquid crystal display device has a structure in which a liquid crystal layer is sandwiched between a light-transmitting upper substrate and a lower substrate, and transmits light to a metal film such as aluminum. A liquid crystal display device has been proposed in which a reflective film having a slit for use is formed on the inner surface of a lower substrate and the reflective film functions as a semi-transmissive reflective film. In this case, in the reflection mode, external light incident from the upper substrate side is reflected by the reflective film arranged on the inner surface of the lower substrate after passing through the liquid crystal layer,
After passing through the liquid crystal layer again, the display is provided from the upper substrate side. On the other hand, in the transmissive mode, light from the backlight incident from the lower substrate side can be displayed outside from the upper substrate side after passing through the liquid crystal layer from the slit formed in the reflective film. Therefore, the area where the slit of the reflective film is formed is the transmissive display area, and the area where the slit of the reflective film is not formed is the reflective display area.

[0004]

In such a transflective liquid crystal display device, for example, when the thickness of the liquid crystal layer is constant, the thickness of the liquid crystal layer is d ₁ and the refractive index of the liquid crystal is Assuming that the anisotropy is Δn and the retardation of the liquid crystal shown as an integrated value of these is Δn · d ₁ , the retardation Δn · d ₁ of the liquid crystal in the reflective display is that the incident light passes through the liquid crystal layer twice. Since it is displayed from 2 × Δnd ₁ , the retardation Δn of the liquid crystal in the portion where transmission display is performed is
d ₁ is represented by 1 × Δnd ₁ because the light from the backlight is displayed only once by passing through the liquid crystal layer.

Since the retardation values required for displaying are different in the reflective display region and the transmissive display region as described above, the polarization states of light are also different, and a bright high-contrast display is simultaneously performed in the reflective display region and the transmissive display region. Can't get

Therefore, a technique has been proposed in which the transmissive display area is made larger than the liquid crystal layer thickness of the reflective display area to make the retardation uniform. FIG. 7 is a diagram showing an example of this type of liquid crystal display device, and is a schematic cross-sectional view of a part of the liquid crystal display device as seen from a direction orthogonal to an alignment treatment direction of a substrate arranged on the lower side. This liquid crystal display device B is
As shown in FIG. 7, liquid crystal is provided between transparent substrates 1 and 2 (hereinafter, substrate 1 may be referred to as “upper substrate 1” and substrate 2 may be referred to as “lower substrate 2”) that are vertically opposed to each other. It comprises the basic structure in which the layer 3 is sandwiched. A transparent electrode 5 is formed on the liquid crystal layer 3 side of the upper substrate 1, and an alignment film 11 is formed on the transparent electrode 5 on the liquid crystal layer 3 side by a predetermined rubbing treatment so as to cover the transparent electrode 5. Has been done.

On the liquid crystal layer 3 side of the lower substrate 2, a reflective layer 16 having a rectangular frame shape in plan view is formed so as to correspond to the reflective display region R. In the reflective layer 16, a plurality of openings 16 a having a rectangular shape in plan view are formed so as to correspond to the transmissive display area T. The color filter 10 is provided on the upper layer side of the reflective layer 16, and the upper layer side of the color filter 10 includes a convex portion 22b and a concave portion 22a formed between adjacent convex portions 22b. A liquid crystal layer thickness control layer (insulating layer) 22 for forming a region where the liquid crystal layer 3 has a large layer thickness and a region where the liquid crystal layer 3 has a small layer thickness is formed.
Further, the liquid crystal layer 3 of the liquid crystal layer thickness control layer (insulating layer) 22b
The transparent electrode 6 is formed on the surface on the side, and the transparent electrode 6 is covered with an alignment film 7 that has been subjected to rubbing treatment (alignment treatment) in the rubbing direction shown by the arrow in FIG. Is formed by.

In the liquid crystal display device B shown in FIG. 7, since the thickness of the liquid crystal layer 3 in the reflective display area R is made smaller than the thickness of the liquid crystal layer 3 in the transmissive display area T, the reflective display area R and the transmissive display area T are shown. It is possible to make the retardation required for display uniform in and.

However, the liquid crystal display device B shown in FIG.
Then, when the thickness of the liquid crystal layer 3 in the reflective display region R is made smaller than the thickness of the liquid crystal layer 3 in the transmissive display region T, the alignment of the liquid crystal molecules 3a is disturbed. That is, in the liquid crystal display device B shown in FIG. 7, the major axis directions of the liquid crystal molecules 3 a forming the liquid crystal layer 3 are aligned in the same direction by the alignment film 7 in the state in which no voltage is applied. The major axis direction of the liquid crystal molecules 3d constituting the surface of the liquid crystal layer thickness control layer 22 is inclined along the surface shape of the liquid crystal layer thickness control layer 22 that controls the layer thickness of the liquid crystal layer 3. Therefore, in the vicinity of the boundary between the transmissive display region T and the reflective display region R, the liquid crystal layer thickness control layer 2 of the lower substrate 2 and the liquid crystal layer 3 is formed.
The angles formed by the major axis direction of the liquid crystal molecules 3f constituting the second side surface are nonuniform as indicated by the circle indicated by the symbol C in FIG. 7, and the alignment of the liquid crystal molecules 3a is disturbed. .

Then, as in the liquid crystal display device B shown in FIG. 7, when the alignment of the liquid crystal molecules 3a located near the boundary between the transmissive display region T and the reflective display region R is disturbed, the transmissive display region T is reflected. There is a fear that disclination may occur near the boundary with the display region R, resulting in display defects such as contrast deterioration.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to obtain a high-contrast display, and to prevent the occurrence of disclination near the boundary between the transmissive display area and the reflective display area. An object of the present invention is to provide a transflective liquid crystal display device that can be suppressed and realize high-quality display. It is another object of the present invention to provide an electronic device including the above liquid crystal display device, which can realize high-quality display.

[0012]

In order to solve the above problems, a liquid crystal display device of the present invention is a liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates, and is used for transmissive display. A transmissive display region, including a reflective display region used for reflective display, by providing an insulating layer at least in the reflective display region, in the reflective display region than the layer thickness of the liquid crystal layer in the transmissive display region A liquid crystal layer having a small thickness, wherein a reflective layer is formed in the reflective display area, the reflective layer is provided with an opening that forms the transmissive display area, and the transmissive display area and the reflective display area are formed. Of the entire length of the boundary line with the region, the angle formed by the orientation treatment direction of the substrate surface on the side where the insulating layer is provided is 0 ± 15.
It is characterized in that the length of the part within the range of degrees is 50% or more.

In the liquid crystal display device of the present invention, the layer thickness of the liquid crystal layer in the reflective display area is smaller than the layer thickness of the liquid crystal layer in the transmissive display area. It is possible to reduce or reduce the difference in retardation required for the display when the display is performed to zero. Therefore, high contrast display can be obtained.

Further, the present inventor has found that the boundary line between the transmissive display area and the reflective display area constitutes the alignment treatment direction of the substrate surface on the side where the insulating layer is provided, that is, the surface of the liquid crystal layer on the insulating layer side. When the liquid crystal molecules are in the same direction as the alignment direction in the non-imprinted state, even if the thickness of the liquid crystal layer is changed between the reflective display region and the transmissive display region, the transmissive display region and the reflective display region It was found that the disclination at the boundary between the transmissive display area and the reflective display area is unlikely to occur because the long axis direction of the liquid crystal molecules does not tilt due to the step difference caused by the layer thickness difference between . Furthermore, the present inventor has found that, within the entire length of the boundary line between the transmissive display region and the reflective display region, the angle formed by the alignment treatment direction of the substrate surface on the side where the insulating layer is provided is within a range of 0 ± 15 degrees. If the length of a certain portion is 50% or more, the proportion of the area in which the liquid crystal molecules are tilted due to the step difference due to the difference in the layer thickness between the transmissive display area and the reflective display area with respect to the display area is small. As described later, it was found that the effect of disclination is less likely to occur near the boundary between the transmissive display area and the reflective display area, and a transflective liquid crystal display device capable of high-quality display can be realized. And

Therefore, in the liquid crystal display device of the present invention, the layer thickness of the liquid crystal layer in the transmissive display area is different from the layer thickness of the liquid crystal layer in the reflective display area, but the boundary between the transmissive display area and the reflective display area is different. Disclination in the vicinity is less likely to occur. Therefore, according to the liquid crystal display device of the present invention, high contrast display can be realized by achieving uniform retardation required for display in the transmissive display region and the reflective display region, and moreover, the transmissive display region and the reflective display region can be realized. It is possible to suppress the disclination in the vicinity of the boundary between and, and to realize high-quality display.

Further, in the above liquid crystal display device, a portion of the entire length of the boundary line, which forms an angle of 0 ± 15 degrees with the alignment treatment direction of the substrate surface on the side where the insulating layer is provided. The length is preferably 70% or more.
If the length of the portion of the surface of the substrate on which the insulating layer is provided and the direction of the alignment treatment in the range of 0 ± 15 degrees is 70% or more, the transmissive display region and the reflective display region with respect to the display region are Since the ratio of the region in which the liquid crystal molecules are tilted due to the step difference due to the difference in the layer thickness between and becomes smaller, the disclination near the boundary between the transmissive display region and the reflective display region will be described later. The effect of being less likely to occur is further enhanced and becomes almost constant.

In the above liquid crystal display device, the opening may be formed by opening the reflection layer in a window shape. When the reflective layer is opened like a window, the opening may have a rectangular shape or a shape surrounded by a curve such as an ellipse.

Further, in the above liquid crystal display device, the opening may be formed by opening the reflection layer in a band shape. With such a liquid crystal display device, it is possible to set the entire length of the boundary line within a range of an angle of 0 ± 15 degrees with the alignment direction of the liquid crystal molecules, which is a transmissive display region with respect to the display region. Since the ratio of the region where the liquid crystal molecules are tilted due to the step difference due to the difference in the layer thickness between the reflective display region and the reflective display region is extremely small, the disclination near the boundary between the transmissive display region and the reflective display region is reduced. It can be very unlikely to occur.

In order to solve the above-mentioned problems, the electronic equipment of the present invention is characterized by including the liquid crystal display device having the above-mentioned configuration. According to this configuration, it is possible to provide an electronic device that can switch between transmissive display and reflective display and can realize high-quality display.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a diagram showing a first embodiment in which the configuration of the present invention is applied to an active matrix type liquid crystal display device. It is a schematic sectional drawing seen from the orientation processing direction of the arranged substrate. Further, FIG. 2 is a schematic plan view of electrodes constituting the liquid crystal display device shown in FIG.

The liquid crystal display device A of the first embodiment has a basic structure in which a liquid crystal layer 3 is sandwiched between substrates 1 and 2 made of transparent glass or the like which are vertically opposed to each other as shown in the sectional structure of FIG. It is equipped with. In the present embodiment, the substrate 1 may be referred to as the upper substrate 1 and the substrate 2 may be referred to as the lower substrate 2.
Although not shown in the drawing, in reality, the substrate 1,
The liquid crystal layer 3 is sandwiched between the substrates 1 and 2 by enclosing the liquid crystal layer 3 between the substrates 1 and 2 and the sealing material with a sealing material interposed on the peripheral side of the liquid crystal layer 2. .
Further, a backlight provided with a light source, a light guide plate and the like is provided below the lower substrate 2, and the upper surface of the upper substrate 1 (observer side) and the lower surface of the lower substrate 2 ( A retardation plate and a polarizing plate are disposed on the internal light source side).

As shown in FIG. 1, a transparent electrode 5 made of ITO (Indium-Tin-Oxide) or the like is formed on the liquid crystal layer 3 side of the upper substrate 1, and the liquid crystal layer 3 side of the transparent electrode 5 is further formed. The alignment film 11 is formed so as to cover the transparent electrode 5. As the alignment film 11, a polymer material film such as polyimide that has been subjected to a predetermined rubbing process (alignment process) is used.

Further, as shown in FIG. 1, a reflective layer 16 is formed on the liquid crystal layer 3 side of the lower substrate 2. Reflective layer 16
Is provided with openings 16a formed by opening the reflection layer 16 in a window shape at predetermined intervals.
Are separated from each other in the left-right direction of the paper surface of FIG. 1 and perpendicular to the paper surface of the drawing, and a plurality of them are formed in a rectangular shape in plan view so as to correspond to the transmissive display area. The reflective layer 16 is
A light-reflecting metal material such as Al or Ag, that is, a metal material having a high reflectance is formed in a rectangular frame shape in a plan view.

On the upper layer side of the reflective layer 16, a color filter 10T for transmissive display and a color filter 10 for reflective display are provided.
A color filter 10 composed of R and R is provided, and a liquid crystal layer thickness control layer (insulating layer) for forming a region having a large layer thickness and a region having a small layer thickness in the liquid crystal layer 3 is provided on the upper side of the color filter 10. ) 22 is formed. Further, the transparent electrode 6 is formed on the surface of the liquid crystal layer thickness control layer (insulating layer) 22b on the liquid crystal layer 3 side, and the alignment film 7 is formed on the transparent electrode 6 so as to cover the transparent electrode 6. Has been done.

In the liquid crystal display device A of this embodiment, the liquid crystal layer thickness control layer (insulating layer) 22b may be composed mainly of a translucent insulating material such as acrylic resin, which is transparent. The electrode 6 is made of, for example, ITO (Indium-Tin).
-Oxide) or the like can be used, and the alignment film 7 can be formed by subjecting a polymer material film such as polyimide to a predetermined rubbing treatment (alignment treatment).

The transparent electrode 6 is drive-controlled by a thin film transistor 17 as a switching element shown in FIG. 2. In the present embodiment, the lower transparent electrode 6 is a pixel electrode,
The upper transparent electrode 5 is the counter electrode, the lower substrate 2 is the element substrate, and the upper substrate 1 is the counter substrate. In this case, the switching elements such as the thin film transistors 17 can be formed on the lower substrate 2 side, for example, but they are not shown in the present embodiment.

Further, in the liquid crystal display device A of this embodiment,
The liquid crystal layer thickness control layer (insulating layer) 22 includes convex portions 22b formed in a protruding form at predetermined intervals and concave portions 22a formed between the convex portions 22b. 22a
An inclined region 24 having an inclined surface inclined at an angle of, for example, 10 ° to 50 ° from the concave bottom surface 23 that is the valley bottom of the
2b and a flat area 25 having a flat surface which is a hill portion. Therefore, the liquid crystal layer thickness control layer (insulating layer) 22
In the inclined region 24, the layer thickness of itself changes continuously in the plane direction, and in the flat region 25, the layer thickness of itself is substantially uniform in the plane direction. The inclined region 24 and the flat region 25 are adjacent to each other and are formed so that the inclined surface and the flat surface are continuous.

In the present embodiment, the inclined surface forming the inclined region 24 is formed in a flat shape, but it may be formed in a gently curved surface shape.

Next, in the liquid crystal display device A of this embodiment,
A region of the liquid crystal layer 3 used for display includes a reflective display region R and a transmissive display region T, and these display portions are formed with different liquid crystal layer thicknesses. Specifically, based on the formation of the liquid crystal layer thickness control layer (insulating layer) 22 described above, the thickness of the liquid crystal layer 3 in the reflective display region R is smaller than the thickness of the liquid crystal layer 3 in the transmissive display region T. It is configured.

Here, the reflective layer 16 described above is formed in the reflective display region R, and the opening edge of the opening 16a of the reflective layer 16 serves as the boundary between the reflective display region R and the transmissive display region T. Therefore, the transmissive display region T is formed in the opening 16a, light is incident from the backlight through the opening 16a, and the incident light passes through the liquid crystal layer 3 and is used for transmissive display. .

The inclined region 24 is included in the transmissive display region T, and the layer thickness of the liquid crystal layer 3 is along the inclined surface of the inclined region 24, that is, the edge of the transmissive display region T, that is, the reflective display region R.
The layer thickness of the insulating layer continuously changes from the boundary between the transparent display region T and the inside. Specifically, the concave portion 22
a liquid crystal layer 3 located on the bottom surface 23 of a or on the upper surface of the inclined surface
Is thicker than the liquid crystal layer 3 located above the flat surface 25 of the convex portion 22b.

In the liquid crystal display device A of this embodiment,
The transmissive display color filter 10T has a transmissive display area T.
And the reflective display color filter 10R is provided at a position corresponding to the reflective display region R. In the liquid crystal display device A, the spectral characteristics of the transmissive display color filter 10T and the reflective display color filter 10R are different, and the color purity of the transmissive display color filter 10T is higher than that of the reflective display color filter 10R. Is also relatively high.

Next, as shown in FIG. 2, the liquid crystal display device A
The display area is formed of a large number of pixels g, and each pixel g is partitioned by a substantially square portion in which three vertically long electrodes 6 are collected when the electrodes 6 are viewed in a plan view. Since the liquid crystal display device A of the present embodiment has a structure for color display, specifically, as shown in FIG. 2, one liquid crystal display device A having a substantially square shape in plan view is divided by three electrodes 6. Pixel g
Is divided into three dots g1, g2, g3.
Then, rectangular concave portions 22a forming the transmissive display region T are provided in the central portions of the electrodes 6 corresponding to these dots g1 to g3, and the electrodes 6 are also formed on the bottom side of these concave portions 22a. ing. Further, the above-mentioned inclined surface 24 is provided on each of the four sides forming the concave portion 22a.

The electrode 6 includes a transmissive display electrode 6b provided on the bottom portion 23 of the concave portion 22a and the inclined region 24, and the convex portion 2.
It can be functionally divided into the reflective display electrode 6a provided in the flat region 25 of 2b and contributes to the transmissive display and the reflective display, respectively. The transmissive display electrode 6 a is located inside the opening of the opening 16 a shown in FIG. 1, and the reflective display electrode 6 b is located on the reflective layer 16.

The horizontal width of each dot g1, g2, g3 is, for example, 80 μm, and the horizontal width of the pixel g composed of each dot g1, g2, g3 is, for example, 240 μm.
The vertical width of each of the dots g1, g2, g3, that is, the vertical width of the pixel g is, for example, 240 μm.

Further, the opening 16 formed in the reflective layer 16
The size of a is formed such that each of the dots g1, g2, and g3 has a size in which the vertical width and the horizontal width of each dot are about several times smaller than the size of one of the dots g1, g2, and g3. The side L2 is arranged so as to be parallel to the rubbing direction (alignment treatment direction) indicated by the arrow in FIG. 2, that is, the alignment direction of the liquid crystal molecules forming the liquid crystal layer 3.

That is, in the present embodiment, of the entire length of the opening edge of the opening 16a which is the boundary between the reflective display area R and the transmissive display area T, the distance corresponding to the length of the long side L2 is the same as the rubbing direction. That is, the angle formed by the long side L2 and the rubbing direction is 0 degree. Further, in the present embodiment, the opening lateral width which is the length of the short side L1 of the opening 16a is, for example, about 15 to 25 μm, and the opening vertical width which is the length of the long side L2 is, for example, about 30 to 50 μm. ing. The ratio [L2 × 2/2 (L1 + L2)] of the length of the long side L2 to the entire length of the opening edge of the opening 16a is 50% or more, preferably 70% or more.

Electrodes 6 are provided at the corners around each dot.
A thin film transistor 17 is formed as a switching element for driving the transistor, and a gate line 18 and a source line 19 for supplying power to the thin film transistor 17 are further wired. Although the thin film transistor 17 is provided as the switching element in the present embodiment, it is also possible to apply a two-terminal type linear element or a switching element having another structure as the switching element.

Further, each colored portion of the color filter 10 is arranged so as to correspond to the plane position of each dot g1, g2, g3. Color filter 10 is "R (red),
G (green) or B (blue) ”, and a light-shielding layer (black matrix) 10a arranged at the boundary between these colored portions. The colored portions may be arranged repeatedly in the order of R (red), G (green), B (blue), and may be arranged in a random arrangement, a mosaic arrangement, or another arrangement order.

In such a liquid crystal display device A, when performing reflective display, light incident from the outside of the device is used, and this incident light is transmitted from the outside of the substrate 1 through the electrode 5 and the alignment film 11. Are guided to the liquid crystal layer 3 side.

Here, in the reflective display region R, after the incident light passes through the liquid crystal layer 3, the alignment film 7, the electrodes 6,
It passes through the convex portion 22 b and the reflective display color filter 10 R and is reflected by the reflective layer 16. Then, the reflected light is reflected again by the reflective display color filter 10R and the convex portion 22.
After passing through b, the electrode 6, the alignment film 7 and the liquid crystal layer 3, it is further returned to the outside of the device via the alignment film 11, the electrode 5 and the substrate 1 to reach the observer, and a reflective color display is performed. Be seen.

On the other hand, in the transmissive display region T, the incident light from the outside passes through the liquid crystal layer 3 and then the alignment film 7, the electrode 6, the concave portion 22a and the transmissive display color filter 10T, Further, the light passes through the opening 16 a of the reflective layer 16. Then, the light passing through the opening 16a passes through the lower substrate 2 and is finally absorbed by a polarizing plate (not shown). In such a reflective color display, the alignment of the liquid crystal of the liquid crystal layer 3 is controlled by the electrodes 5 and 6,
Bright and dark display is performed by changing the transmittance of light passing through the liquid crystal layer 3.

In the case of transmissive display, the light emitted from the backlight enters through the substrate 2. In this case, in the transmissive display area T, the light incident from the substrate 2 has the transmissive display color filter 10T and the concave portion 22.
After passing through a, the electrode 6, the alignment film 7, the liquid crystal layer 3, the alignment film 11, the electrode 5, and the substrate 1 are sequentially transmitted to perform a transmission color display.

On the other hand, in the reflective display region R, the substrate 2
Light incident from is reflected by the reflective layer 16 and finally absorbed by a polarizing plate (not shown). In such a transmissive color display as well, by controlling the alignment of the liquid crystal of the liquid crystal layer 3 with the electrodes 5 and 6, it is possible to change the transmittance of light passing through the liquid crystal layer 3 to perform bright and dark display.

Thus, the liquid crystal display device A of this embodiment
In the reflective display mode, incident light passes through the liquid crystal layer 3 twice, and in the transmissive display mode, light emitted from the backlight passes through the liquid crystal layer 3 once. Although the number of times of passing through the liquid crystal layer 3 differs depending on the display form, the thickness of the liquid crystal layer 3 in the transmissive display region T for performing transmissive display is larger than the thickness of the liquid crystal layer 3 in the reflective display region R. Therefore, the liquid crystal layer 3 through which light passes during display
The distance can be made uniform in the reflective display area R and the transmissive display area T. Therefore, the retardation between the reflective display region R and the transmissive display region T becomes uniform, and bright and high-contrast display can be obtained in both the reflective display and the transmissive display.

Further, in the liquid crystal display device A of this embodiment, the layer thickness of the liquid crystal layer 3 in the transmissive display region T and the reflective display region R are set.
Although the layer thickness of the liquid crystal layer 3 is different from that of the liquid crystal layer 3, the opening 1 which is a boundary line between the reflective display region R and the transmissive display region T is formed.
Since the ratio of the length of the long side L2, which is the same direction as the rubbing direction, of the entire length of the opening edge of 6a is 50% or more, and preferably 70% or more, as shown below, the display area is The proportion of the region in which the liquid crystal molecules 3a are tilted due to the step difference due to the difference in layer thickness between the transmissive display region T and the reflective display region R is small.

FIG. 3 is a partial plan view for explaining the alignment state of the liquid crystal molecules in the liquid crystal display device of the present embodiment when no voltage is applied, and is a structure necessary for explaining the alignment state of the liquid crystal molecules. Only the elements are shown. In FIG. 3, the same components as those in FIG. 1 or 2 are designated by the same reference numerals.

In FIG. 3, reference numerals 3b, 3c and 3d are
Among the liquid crystal molecules 3a forming the liquid crystal layer 3, the liquid crystal molecules forming the surface on the liquid crystal layer thickness control layer (insulating layer) 22 side are shown. Here, focusing on the direction crossing the long side L2 of the opening 16a formed in the reflective layer 16, FIG.
As shown in FIG. 3, both the liquid crystal molecules 3b located on the flat region 25 of the convex portion 22b, the liquid crystal molecules 3c located on the inclined region 24, and the liquid crystal molecules 3e located on the bottom 23 of the recess 22a are included. The major axis direction is aligned with the rubbing direction indicated by the arrow in FIG.

Focusing on the direction crossing the short side L1 of the opening 16a, the major axis direction of the liquid crystal molecule 3b located above the flat region 25 and the liquid crystal molecule 3e located above the bottom 23 is the opening. Similar to the direction traversing the long side L2 of 16a, they are aligned in the same direction as the rubbing direction, but as shown in FIG. 3, the long axis direction of the liquid crystal molecules 3d located on the inclined region 24 is the liquid crystal layer. It is inclined along the surface shape of the layer thickness control layer (insulating layer) 22, and the angle formed with the lower substrate 2 is uneven.

That is, in the liquid crystal display device A of the present embodiment, the region where the liquid crystal molecules 3a in the no voltage applied state are tilted due to the step difference due to the difference in layer thickness between the transmissive display region T and the reflective display region R , Only the inclined region 24 located in the direction crossing the short side L1. As described above, in the liquid crystal display device A of the present embodiment, the ratio of the length of the long side L2 to the entire length of the opening edge of the opening 16a is 50% or more, and thus the short side L1 in the display area is L1. The ratio of the inclined region 24 located in the direction crossing the direction is small. Further, when the ratio of the length of the long side L2 to the total length of the opening edge of the opening 16a is 70% or more, the ratio of the inclined region 24 located in the direction crossing the short side L1 in the display region is more It will be even less.

Thus, the liquid crystal display device A of this embodiment
Is a transmissive display area T and a reflective display area R with respect to the display area.
Since the ratio of the region in which the liquid crystal molecules 3a are tilted due to the step difference caused by the difference in the layer thickness between the liquid crystal layer 3 and the layer thickness of the liquid crystal layer 3 in the transmissive display region T and the layer of the liquid crystal layer 3 in the reflective display region R are small. Although the thickness is different, disclination is less likely to occur near the boundary between the reflective display region R and the transmissive display region T, and high-quality display can be achieved.

Further, in the present embodiment, since the liquid crystal layer thickness control layer (insulating layer) 22b is provided with the inclined surface 24, the liquid crystal layer 3 does not have a steep layer thickness change and is more discrete. The generation of nations is suppressed, and it becomes more difficult for liquid crystal alignment defects to occur.

Further, in this embodiment, the color filter 10T for transmissive display and the color filter 10 for reflective display are used.
Since the spectral characteristic of the color filter 10 is different from that of R, and the color purity of the transmissive display color filter 10T is relatively higher than that of the reflective display color filter 10R, the color filter 10 is transmitted twice in the reflective mode. It is possible to reduce the difference in color tone between the obtained light and the light obtained by passing through the color filter 10 once in the transmission mode,
It is possible to make the lightness and darkness of colors the same in the transmissive display and the reflective display.

In the liquid crystal display device of the present invention, of the entire length of the boundary line between the reflective display area and the reflective display area, the alignment treatment direction (rubbing direction) of the substrate surface on the side where the insulating layer is provided is set. If the length of the portion whose angle is in the range of 0 ± 15 degrees is 50% or more, the shape of the opening 16a is
The shape is not limited to the example shown in the first embodiment, and may be the shape shown in FIGS. 4 and 5, for example.

FIG. 4 is a view showing another example of the reflective layer constituting the liquid crystal display device of the present invention, and is a partial plan view showing a portion corresponding to FIG. 3 described in the first embodiment. is there. The reflective layer shown in FIG. 4 is formed by opening the reflective layer in a window shape and has an opening 16 surrounded by a smooth curve.
b is provided. Also in the opening 16b shown in FIG. 4, similarly to the example shown in the above-described first embodiment, of the entire length of the opening edge, the angle formed with the rubbing direction shown by the arrow in FIG. 4 is 0 ± 15 degrees. The length of the part that is the range is 50%
That is all. Therefore, the ratio of the region where the liquid crystal molecules are tilted due to the step difference due to the difference in layer thickness between the transmissive display region T and the reflective display region R with respect to the display region is small.

FIG. 5 is a view showing another example of the reflective layer constituting the liquid crystal display device of the present invention, and is a partial plan view showing only one dot. The reflective layer shown in FIG. 5 is provided with an opening 16c formed by opening the reflective layer in a strip shape. The opening 16c shown in FIG. 5 extends parallel to the rubbing direction indicated by the arrow in FIG. Therefore, there is no region where the liquid crystal molecules are tilted due to the step due to the difference in layer thickness between the transmissive display region T and the reflective display region R.

Furthermore, the liquid crystal display device of the present invention is not limited to the above example, and for example, one or both of the color filter 10 and the liquid crystal layer thickness control layer (insulating layer) 22 is used as the upper substrate. 1 may be provided,
It can also be applied to a simple matrix type liquid crystal display device. Even in this case, the same effect as that of the example shown in the first embodiment can be obtained.

[Electronic Equipment] Examples of electronic equipment equipped with the liquid crystal display device of the above embodiment will be described. Figure 6 (a)
FIG. 4 is a perspective view showing an example of a mobile phone. Figure 6 (a)
In the above, reference numeral 500 indicates a mobile phone main body, and reference numeral 50
Reference numeral 1 denotes a liquid crystal display unit using the above liquid crystal display device A.

FIG. 6B is a perspective view showing an example of a portable information processing device such as a word processor and a personal computer. Figure 6
In (b), reference numeral 600 is an information processing device and reference numeral 60.
Reference numeral 1 denotes an input unit such as a keyboard, reference numeral 603 denotes an information processing apparatus main body, and reference numeral 602 denotes a liquid crystal display unit using the liquid crystal display device A described above.

FIG. 6C is a perspective view showing an example of a wrist watch type electronic device. In FIG. 6C, reference numeral 700
Indicates a watch body, and reference numeral 701 indicates the liquid crystal display device A.
The liquid crystal display part using is shown.

As described above, the electronic apparatus shown in FIG. 6 is provided with the liquid crystal display section using the liquid crystal display device A of the above-mentioned embodiment, and therefore, it is of high quality having the bright and high contrast display section in various environments. It is possible to realize an electronic device that can realize various color displays. In addition, it is possible to realize an electronic device including a display section with few display defects even at the boundary between the reflective and transmissive display areas.

[0062]

EXAMPLES Hereinafter, examples will be described in detail. First, only the shape of the opening provided in the reflective layer is the first
Liquid crystal display devices of Test Examples 1 to 3 different from the liquid crystal display device of the embodiment were prepared. “Test Example 1” FIG. 8A is a plan view showing a reflective layer constituting the liquid crystal display device of Test Example 1. As shown in FIG. 8A, in Test Example 1, the reflective layer had a length of 240 μm.
m, the square of 240 μm in width, the angle between the edge of the reflective layer and the edge of the rubbing direction is 30 degrees, and the opening 16a
8 is parallel to the rubbing direction indicated by the arrow in FIG. That is, the angle formed by the long side 11 and the rubbing direction is 0 degree.

"Test Example 2" The liquid crystal display device of Test Example 2 is
This is different from the liquid crystal display device of Test Example 1 only in that the angle formed by the long side 11 of the opening 16a and the rubbing direction is 15 degrees.

[Test Example 3] FIG. 8B is a plan view showing the reflective layer constituting the liquid crystal display device of Test Example 3. As shown in FIG. 8B, the liquid crystal display device of Test Example 3 is different from the liquid crystal display device of Test Example 1 in that the long side l of the opening 16a is
3 is parallel to the edge of the reflective layer. That is, the angle formed by the long side 13 and the rubbing direction is 30 degrees. Then, in the liquid crystal display devices of Test Example 1 to Test Example 3, the ratio [l / (w + l)%] of the length of the long side to the entire length of the opening edge of the opening 16a is changed to obtain a black display reflectance. I investigated the relationship.

The results are shown in FIG. FIG. 9 shows the ratio of the length of the long side to the entire length of the opening edge of the opening [l / (w +
1)%] and the reflectance of black display, where the vertical axis represents the reflectance and the horizontal axis represents the ratio of the length of the long side.

From FIG. 9, it was confirmed that the liquid crystal display devices of Test Example 1 and Test Example 2 had smaller reflectance and higher contrast and higher quality display than the liquid crystal display device of Test Example 3. . Further, in the liquid crystal display device of Test Example 2, the rate of change in reflectance of black display is small when the ratio of the length of the long side to the total length of the opening edge of the opening is changed. From this, it can be seen that the effect of reducing the reflectance can be obtained by setting the angle between the long side 11 of the opening 16a and the rubbing direction within the range of 0 ± 15 degrees. Further, in the liquid crystal display devices of Test Example 1 and Test Example 2, when the ratio of the length of the long side to the entire length of the opening edge of the opening is 50% or more, the effect of reducing the reflectance may be obtained. It could be confirmed. Furthermore, in the liquid crystal display devices of Test Example 1 and Test Example 2,
The ratio of the length of the long side to the total length of the opening edge of the opening is 70.
It was confirmed that when the ratio was at least%, the reflectance was further reduced and the reflectance value was substantially constant.

[0067]

As described above in detail, in the liquid crystal display device of the present invention, the layer thickness of the liquid crystal layer in the reflective display area is smaller than the layer thickness of the liquid crystal layer in the transmissive display area. Therefore, it is possible to make the difference in retardation between the reflective display and the transmissive display small or zero. Therefore, high contrast display can be obtained.

Further, in the liquid crystal display device of the present invention, of the entire length of the boundary line between the transmissive display region and the reflective display region, the angle formed by the alignment treatment direction of the substrate surface on the side where the insulating layer is provided is 0.
Since the length of the portion within the range of ± 15 degrees is 50% or more, disclination is less likely to occur near the boundary between the transmissive display area and the reflective display area.

Therefore, according to the liquid crystal display device of the present invention,
By achieving uniform retardation in the transmissive display area and the reflective display area, high-contrast display can be realized, and further, disclination in the vicinity of the boundary between the transmissive display area and the reflective display area can be suppressed, High quality display can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment in which the configuration of the present invention is applied to an active matrix type liquid crystal display device, in which a part of the liquid crystal display device in which no voltage is applied is arranged on the lower side. It is a schematic sectional drawing seen from the orientation processing direction of a substrate.

FIG. 2 is a schematic plan view of electrodes forming the liquid crystal display device shown in FIG.

FIG. 3 is a partial plan view for explaining an alignment state of liquid crystal molecules in the liquid crystal display device of the present embodiment.

FIG. 4 is a plan view showing another example of a reflective layer constituting the liquid crystal display device of the present invention.

FIG. 5 is a plan view showing another example of a reflective layer constituting the liquid crystal display device of the present invention.

FIG. 6 is a perspective view showing some examples of electronic devices according to the present invention.

FIG. 7 is a diagram showing an example of a liquid crystal display device of this type, in which a part of the liquid crystal display device in which no voltage is applied is perpendicular to the alignment treatment direction of the substrate arranged on the lower side. It is the schematic sectional drawing seen from.

FIG. 8 is a plan view showing a reflective layer that constitutes a liquid crystal display device according to an embodiment of the present invention. FIG. 8A shows Test Example 1, Test Example 2, and FIG. 8B shows Test Example 3. Shown respectively.

FIG. 9 is a graph showing the relationship between the ratio of the length of the long side to the entire length of the opening edge of the opening of the reflective layer and the reflectance of black display in the liquid crystal display device of the test example.

[Explanation of symbols]

A liquid crystal display 1 Upper substrate 2 Lower substrate 3 Liquid crystal layer 10 color filters Color filter for 10T transmissive display 10R Color filter for reflective display 16 Reflective layer 16a opening 22 Liquid crystal layer thickness control layer (insulating layer) 24 inclined surface 25 flat surface R reflective display area T transparent display area

Continued front page    F term (reference) 2H048 BA02 BB02 BB07 BB10 BB44                 2H090 HA03 HA07 HC11 HC12 HC18                       HD06 JA03 JA09 JB02 LA04                       LA20                 2H091 FA14Y GA06 GA07 GA13                       KA02 LA03 LA11 LA12 LA13                       LA18

Claims (7)

[Claims] 1. A liquid crystal display device in which a liquid crystal layer is sandwiched between a pair of substrates, the liquid crystal display device including a transmissive display region used for transmissive display and a reflective display region used for reflective display. By providing an insulating layer in the reflective display region, the layer thickness of the liquid crystal layer in the reflective display region is smaller than the layer thickness of the liquid crystal layer in the transmissive display region, the reflective layer in the reflective display region. The reflective layer is provided with an opening that forms the transmissive display region, and the substrate on the side where the insulating layer is provided, of the entire length of the boundary line between the transmissive display region and the reflective display region. A liquid crystal display device characterized in that the length of a portion whose angle with the orientation direction of the surface is in the range of 0 ± 15 degrees is 50% or more. 2. An angle formed by the alignment treatment direction of the substrate surface on the side where the insulating layer is provided is 0 out of the entire length of the boundary line.
The liquid crystal display device according to claim 1, wherein the length of the portion within the range of ± 15 degrees is 70% or more. 3. The liquid crystal display device according to claim 1, wherein the opening is formed by opening the reflection layer in a window shape. 4. The liquid crystal display device according to claim 3, wherein the opening is rectangular. 5. The liquid crystal display device according to claim 3, wherein the opening has a shape surrounded by a curved line. 6. The liquid crystal display device according to claim 1, wherein the opening is formed by opening the reflection layer in a strip shape. 7. An electronic apparatus comprising the liquid crystal display device according to claim 1. Description: