JP2008107526A - Electro-optical device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electro-optical device by which an electrode can be finely patterned. <P>SOLUTION: The device includes a reflection film 44 formed in a reflective display region R of an element substrate 21, and a frame portion 11a and a belt-like portion 11b formed on the reflection film 44. The frame portion 11a and the belt-like portion 11b are disposed closer to a liquid crystal layer 23 than the reflection film 44, and at least partially formed on a flat face in the reflective display region R. The reflection film 44 includes a ruggedness portion 44a formed in a region overlapped in a planar view with the frame portion 11a and the non-belt-like portion 11b, and a flat portion 44b formed in a region overlapped with the frame portion 11a and the belt-like portion 11b in a planar view. A scattering region to scatter the light reflected by the reflection film 44 is formed in a region of the reflective display region R on a counter substrate 22, overlapped with the frame portion 11a and the belt-like portion 11b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electro-optical device such as a liquid crystal display device and an electronic apparatus including the same.

2. Description of the Related Art Conventionally, transflective liquid crystal display devices that use external light in a bright place and use an internal light source such as a backlight in a dark place to make a display visible have been used. This transflective liquid crystal display device adopts a display method that combines a reflective type and a transmissive type. By switching to either the reflective mode or the transmissive mode depending on the ambient brightness, In this way, clear display can be performed even when the surroundings are dark while reducing power consumption.
By the way, in such a transflective liquid crystal display device, a transmissive display region for performing transmissive display and a reflective display region for performing reflective display are provided in one pixel region. A reflective film that reflects external light incident on the liquid crystal layer toward the incident surface is provided in a region corresponding to the reflective display region in the liquid crystal display device. On the surface of the reflective film, there are formed irregularities for reflecting light while scattering it for the purpose of obtaining good display characteristics in reflective display.

Further, as one means for achieving a wide viewing angle of the liquid crystal display device, a method of generating an electric field in the substrate direction with respect to the liquid crystal layer to control alignment of liquid crystal molecules (hereinafter referred to as a horizontal electric field method) is used. As such a lateral electric field method, an IPS (In-Plane Switching) method and an FFS (Fringe-Field Switching) method are known (for example, see Patent Document 1).
In a liquid crystal display device using such a horizontal electric field method, a pixel electrode and a common electrode, which are a pair of electrodes for driving liquid crystal molecules, are provided on one of a pair of substrates that sandwich a liquid crystal layer. For example, a pixel electrode in an FFS mode liquid crystal display device includes a plurality of band-like electrodes provided at intervals in order to generate an electric field with a common electrode.
JP 2005-338256 A

  However, the following problems remain in the conventional liquid crystal display device. That is, in the liquid crystal display device using the transflective FFS method, the pixel electrode in the reflective display region may be provided on the uneven surface corresponding to the reflective display region. Since the strip electrode is formed on the concavo-convex surface, it becomes difficult to finely process the strip electrode, and there is a problem that the strip electrode may be disconnected or a short circuit may occur with another adjacent strip electrode.

  The present invention has been made in view of the above-described conventional problems, and provides an electro-optical device capable of preventing disconnection and short-circuiting of a strip electrode formed in a region corresponding to a reflective display region, and an electronic apparatus including the same. Objective.

  The present invention employs the following configuration in order to solve the above problems. That is, the electro-optical device according to the present invention is an electro-optical device in which an electro-optical layer is sandwiched between first and second substrates and a reflective display region is provided in each pixel region, and the reflection of the first substrate is performed. A reflective film provided in a display area; and a strip-shaped electrode provided on the reflective film, wherein the strip-shaped electrode is disposed closer to the electro-optic layer than the reflective film, and at least a part of the reflective display An uneven portion formed on a flat surface in the region, and the reflective film is provided in a region overlapping with the non-formation region of the strip electrode in plan view, and a flat portion formed in the region overlapping with the strip electrode in plan view And a scattering region for scattering the light reflected by the reflective film is formed in a region of the reflective display region of the second substrate that overlaps the strip electrode.

In the present invention, the formation surface of the strip electrode is a flat surface, so that the occurrence of disconnection of the strip electrode or a short circuit with other adjacent strip electrodes can be suppressed, and the formation is performed in the region corresponding to the flat strip electrode. The light reflected by the reflected film can be scattered and emitted from the second substrate.
That is, light that travels toward the non-formation region of the strip-shaped electrode in the surface of the reflective film is reflected while being scattered toward the second substrate in the reflective film because the surface of the reflective film is an uneven surface. Further, the light traveling toward the band electrode formation region in the surface of the reflection film is specularly reflected toward the second substrate in the reflection film because the band electrode formation surface is a flat surface. Then, the specular reflection light incident on the second substrate enters a scattering region provided corresponding to the reflective display region. Thereafter, the specular reflection light is scattered in the scattering region and emitted from the second substrate. For this reason, even if the formation surface of a strip electrode is a flat surface, it can prevent that the display characteristic of the image in a reflective display area falls by specular reflection. Here, since the uneven portion is formed in the non-formation region of the strip-shaped electrode in the surface of the reflective film, the light incident on the reflective film is more reliably compared to making the entire surface of the reflective film flat. The display characteristics of the image in the reflective display area can be improved.
In addition, by providing a flat portion in a region of the reflective film that overlaps with the band electrode formation region, the band electrode formation surface becomes a flat surface. Thereby, since the patterning of a some strip | belt-shaped electrode can be performed accurately, the disconnection of a strip | belt-shaped electrode or a short circuit with other adjacent strip-shaped electrodes can be prevented. And it can suppress that the electric field which generate | occur | produces in an electro-optic layer is disturbed by forming a strip | belt-shaped electrode on a flat surface.

In the electro-optical device according to the aspect of the invention, it is preferable that the scattering region is formed only in a region overlapping with the strip electrode.
In the present invention, the brightness of image display by the reflective display region can be ensured by forming the scattering region only in the region corresponding to the strip electrode on the second substrate. That is, the specular reflected light reflected at the flat portion of the reflective film mainly travels toward a region corresponding to the electrode formation region of the second substrate. For this reason, it is possible to prevent the scattered reflected light reflected by the concavo-convex portion of the reflective film from entering the scattering region on the second substrate and being excessively scattered and reducing the brightness of the image in the reflective display region.

In the electro-optical device according to the aspect of the invention, the second substrate may include a substrate body serving as a base, and a scattering uneven portion may be formed in the scattering region on the surface of the substrate body.
In this invention, the light reflected by the reflective film is emitted from the second substrate after being scattered by the scattering irregularities formed in the region corresponding to the reflective display region. In this way, it is possible to prevent the display characteristics of the image from being deteriorated even if it is specularly reflected on the reflective film.

In the electro-optical device according to the aspect of the invention, it is preferable that the scattering uneven portion is formed on a surface of the substrate body on the electro-optical layer side.
In this invention, when the scattering irregularities are formed on one surface of the substrate body that is close to the electro-optic layer, when another optical member is formed on one surface of the substrate body, the scattering irregularities are flush with the scattering irregularities. Since the processing is performed, the second substrate can be easily manufactured.

In the electro-optical device according to the aspect of the invention, it is preferable that the scattering uneven portion is filled with a filler having a refractive index different from that of the electro-optical layer.
In this invention, by filling the scattering irregularities with the filler, the refractive indexes of the scattering irregularities and the electro-optic layer can be made different from each other, and light can be reliably scattered by the scattering irregularities.

In the electro-optical device according to the aspect of the invention, a scattering plate may be provided in the scattering region of the second substrate.
In this invention, the light reflected by the reflective film is emitted from the scattering plate provided in the area corresponding to the reflective display area. In this way, it is possible to prevent the display characteristics of the image from being deteriorated even if it is specularly reflected on the reflective film.

An electronic apparatus according to the present invention includes the above-described liquid crystal display device.
According to the present invention, it is possible to prevent deterioration in display characteristics of an image in the reflective display area and to prevent occurrence of disconnection of a strip electrode formed in a region overlapping with the reflective film in a plan view or a short circuit with another adjacent strip electrode. it can.

[First Embodiment]
Hereinafter, a liquid crystal display device (electro-optical device) according to a first embodiment of the invention will be described with reference to the drawings. In each drawing used in the following description, the scale is appropriately changed to make each member a recognizable size. Here, FIG. 1 is an equivalent circuit diagram showing a liquid crystal display device, FIG. 2 is a plan view of a sub-pixel region, and FIG. 3 is a cross-sectional view taken along line AA in FIG.

[Liquid Crystal Display]
A liquid crystal display device (electro-optical device) 1 according to this embodiment is a color liquid crystal display device, and includes three sub-pixel regions that output light of each color of R (red), G (green), and B (blue). This is a liquid crystal display device that constitutes one pixel. Here, the display area which is the minimum unit constituting the display is referred to as a “sub-pixel area”.

  First, a schematic configuration of the liquid crystal display device 1 will be described. As shown in FIG. 1, the liquid crystal display device 1 has a plurality of sub-pixel regions constituting an image display region arranged in a matrix. In each of the plurality of sub-pixel regions, a pixel electrode 11 and a TFT (Thin Film Transistor) element (drive element) 12 for switching control of the pixel electrode 11 are formed. The TFT element 12 has a source connected to a data line 14 extending from a data line driving circuit 13 provided in the liquid crystal display device 1 and a gate extending from a scanning line driving circuit 15 provided in the liquid crystal display device 1. The drain is connected to the pixel electrode 11.

The data line driving circuit 13 is configured to supply image signals S1, S2,..., Sn to the sub-pixel regions via the data line. Here, the data line driving circuit 13 may supply the image signals S1 to Sn line-sequentially in this order, or may supply each of the data lines 14 adjacent to each other for each group.
The scanning line driving circuit 15 is configured to supply scanning signals G1, G2,..., Gm to the sub-pixel regions via the scanning lines 16. Here, the scanning line drive circuit 15 supplies the scanning signals G1 to Gm in a pulse-sequential manner at predetermined timing.

  Further, in the liquid crystal display device 1, the TFT elements 12 that are switching elements are turned on for a predetermined period by the input of the scanning signals G <b> 1 to Gm, so that the image signals S <b> 1 to Sn supplied from the data line 14 are predetermined. The pixel electrode 11 is written with timing. A predetermined level of image signals S1 to Sn written to the liquid crystal via the pixel electrode 11 is held for a certain period between the pixel electrode 11 and a common electrode 45 described later.

Next, a detailed configuration of the liquid crystal display device 1 will be described with reference to FIGS. In FIG. 2, the counter substrate is not shown. In FIG. 2, the major axis direction of a substantially rectangular sub-pixel region in plan view is defined as an X-axis direction, and the minor axis direction is defined as a Y-axis direction. Furthermore, in FIG. 3, illustration of the strip | belt-shaped part (strip-shaped electrode) 11b is abbreviate | omitted suitably.
As shown in FIG. 2 and FIG. 3, the liquid crystal display device 1 divides each sub-pixel region into two portions in the major axis direction (X-axis direction) of the sub-pixel region (the major axis direction of the sub-pixel region). Of the two regions, a region corresponding to the sub-pixel region and the region separated from the scanning line 16) is a reflective display region R, and another region is a transmissive display region T. ing.

As shown in FIG. 3, the liquid crystal display device 1 includes an element substrate (first substrate) 21, a counter substrate (second substrate) 22 disposed opposite to the element substrate 21, and the element substrate 21 and the counter substrate 22. A liquid crystal layer (electro-optic layer) 23 sandwiched between them, a polarizing plate 24 provided on the outer surface side of the element substrate 21 (opposite side of the liquid crystal layer 23), and a polarizing plate 25 provided on the outer surface side of the counter substrate 22. And. The liquid crystal display device 1 is configured to be irradiated with illumination light from the outer surface side of the element substrate 21.
Further, the liquid crystal display device 1 is provided with a sealing material (not shown) along an edge of a region where the element substrate 21 and the counter substrate 22 face each other. The seal material, the element substrate 21 and the counter substrate 22 are provided. Thus, the liquid crystal layer 23 is sealed.

The element substrate 21 includes a substrate main body 31 made of a light-transmitting material such as glass, quartz, and plastic, a gate insulating film 32 sequentially stacked on the inner surface (the liquid crystal layer 23 side) of the substrate main body 31, and a first interlayer. An insulating film 33, a liquid crystal layer thickness adjusting layer 34, a second interlayer insulating film 35, and an alignment film 36 are provided.
The element substrate 21 includes a scanning line 16 disposed on the inner surface of the substrate body 31, a data line (shown in FIG. 2) 14 disposed on the inner surface of the gate insulating film 32, a semiconductor layer 41, a source An electrode 42, a drain electrode 43, a reflective film 44 disposed on the inner surface of the liquid crystal layer thickness adjusting layer 34, a common electrode 45 disposed on the inner surface of the first interlayer insulating film 33 and the reflective film 44, The pixel electrode 11 is provided on the inner surface of the second interlayer insulating film 35.

The gate insulating film 32 is made of a translucent material such as SiO ₂ (silicon oxide), for example, and is provided so as to cover the scanning lines 16 formed on the substrate body 31.
Like the gate insulating film 32, the first interlayer insulating film 33 is made of a light-transmitting material such as SiN (silicon nitride), for example, and the data line 14 and the semiconductor layer 41 formed on the gate insulating film 32. The source electrode 42 and the drain electrode 43 are provided so as to cover.

  The liquid crystal layer thickness adjusting layer 34 is provided in a portion corresponding to the reflective display region R on the surface of the first interlayer insulating film 33, and is formed by patterning a resin material such as acrylic. Further, the liquid crystal layer thickness adjusting layer 34 has an uneven surface that overlaps with a region where the pixel electrode 11 is not formed through the reflective film 44, the common electrode 45, and the second interlayer insulating film 35 in plan view among the inner surface. In addition, a region overlapping with the pixel electrode 11 is a flat surface. This uneven surface is formed by partially patterning the liquid crystal layer thickness adjusting layer 34. The liquid crystal layer thickness adjusting layer 34 has a different thickness from the liquid crystal layer 23 in the reflective display region R and the liquid crystal layer 23 in the transmissive display region T, and is applied to the light transmitted through the liquid crystal layer 23. The phase difference between the reflective display region R and the transmissive display region T is optimized.

Similar to the first interlayer insulating film 33, the second interlayer insulating film 35 is made of a light-transmitting material such as SiN (silicon nitride), and is formed on the first interlayer insulating film 33 and the reflective film 44. The common electrode 45 is provided so as to cover it. In the first and second interlayer insulating films 33 and 35, contact holes H penetrating the first and second interlayer insulating films 33 and 35 are formed in regions overlapping the drain electrode 43 in plan view. Here, the region of the inner surface of the second interlayer insulating film 35 that overlaps with the non-formed region of the pixel electrode 11 in plan view corresponds to the uneven surface of the liquid crystal layer thickness adjusting layer 34. A certain uneven portion 35a is formed. Similarly, the second interlayer insulating film 35 has a flat portion 35b that is a flat surface because a region of the inner surface that overlaps the pixel electrode 11 in plan view overlaps the flat surface of the liquid crystal layer thickness adjusting layer 34. Yes.
The alignment film 36 is made of, for example, a resin material such as polyimide, and is provided so as to cover the pixel electrode 11 formed on the second interlayer insulating film 35. The surface of the alignment film 36 is subjected to an alignment process in which the short axis direction (Y-axis direction) of the sub-pixel region shown in FIG.

  As shown in FIG. 2, the data line 14 is arranged along the major axis direction (X-axis direction) of the rectangular sub-pixel region in plan view. The scanning lines 16 are arranged along the minor axis direction (Y axis direction) of the sub-pixel region. Therefore, the data lines 14 and the scanning lines 16 are wired in a substantially lattice shape in plan view.

  As shown in FIGS. 2 and 3, the semiconductor layer 41 is partially formed in a region overlapping the scanning line 16 through the gate insulating film 32 in plan view, and is made of a semiconductor such as amorphous silicon or polysilicon. Yes. Further, the source electrode 42 is branched from the data line 14 and is formed so as to partially cover the semiconductor layer 41. The drain electrode 43 is formed so as to partially cover the semiconductor layer 41 and is electrically connected to the pixel electrode 11 through a contact hole H penetrating the first and second interlayer insulating films 33 and 35. is doing. These semiconductor layer 41, source electrode 42 and drain electrode 43 constitute the TFT element 12. The TFT element 12 is provided in the vicinity of the intersection of the data line 14 and the scanning line 16.

  The reflective film 44 is formed by patterning a light-reflective metal film such as aluminum or silver, and is formed on the inner surface of the liquid crystal layer thickness adjusting layer 34. Here, of the inner surface of the reflective film 44, the liquid crystal layer thickness adjusting layer 34 is an uneven surface in a region overlapping the non-formed region of the pixel electrode 11 through the common electrode 45 and the second interlayer insulating film 35 in plan view. Therefore, it is an uneven portion 44a which is an uneven surface. Similarly, a region of the inner surface of the reflective film 44 that overlaps the pixel electrode 11 through the common electrode 45 and the second interlayer insulating film 35 in plan view is a flat portion 44b that is a flat surface. The reflective film 44 can be scattered and reflected at the uneven portion 44a, and can be specularly reflected at the flat portion 44b.

  The common electrode 45 is formed so as to cover the first interlayer insulating film 33 and the reflective film 44, and is made of a translucent conductive material such as ITO (indium tin oxide). For example, a predetermined constant voltage or 0 V used for driving the liquid crystal layer 23, or a predetermined constant potential and another predetermined constant potential different from the common electrode 45 are periodically (every frame period). Alternatively, a signal that changes every field period) is applied. Here, the region of the inner surface of the common electrode 45 that overlaps with the non-formation region of the pixel electrode 11 through the second interlayer insulating film 35 in plan view corresponds to the uneven surface of the liquid crystal layer thickness adjustment layer 34. Therefore, it has an uneven surface. Similarly, a region of the inner surface of the common electrode 45 that overlaps the pixel electrode 11 through the second interlayer insulating film 35 in plan view is a flat surface because it corresponds to the flat surface.

  The pixel electrode 11 is formed on the second interlayer insulating film 35, and has a substantially ladder shape in plan view as shown in FIG. 2. Like the common electrode 45, the pixel electrode 11 has a light-transmitting conductive property such as ITO. Consists of materials. The pixel electrode 11 extends in the short axis direction (Y-axis direction) of the sub-pixel region and the long-axis direction (Y-axis direction) of the sub-pixel region. And a plurality of (15 pieces) belt-like portions 11b arranged at intervals in the (X-axis direction).

The frame portion 11a has a configuration in which two pairs of strip electrodes are connected to form a substantially rectangular frame shape in plan view, and two pairs of sides facing each other are along the X-axis direction and the Y-axis direction, respectively. It is extended.
The strip portions 11b are formed so as to be parallel to each other, and both ends thereof are connected to portions of the frame portion 11a extending along the Y-axis direction. Moreover, the strip | belt-shaped part 11b is provided so that the extension direction may become non-parallel to the Y-axis direction. That is, the strip portion 11b is formed so that its extending direction is closer to the scanning line 16 as it goes from one end away from the data line 14 toward the other end in plan view. Here, a part of the frame portion 11 a and the strip-like portion 11 b formed on the second interlayer insulating film 35 in the region corresponding to the reflective display region R is formed on the flat portion 35 b of the second interlayer insulating film 35. Has been.

  As described above, the liquid crystal display device 1 is configured to apply a voltage between the strip portion 11b and the common electrode 45 and drive the liquid crystal by an electric field (lateral electric field) in the substrate plane direction generated thereby. Accordingly, the pixel electrode 11 and the common electrode 45 constitute an FFS type electrode structure.

On the other hand, as shown in FIG. 3, the counter substrate 22 is sequentially formed on a substrate body 51 made of a translucent material such as glass, quartz, and plastic, and on the inner surface (the liquid crystal layer 23 side) of the substrate body 51. A light shielding film 52, a color filter layer 53, and an alignment film 54 are provided.
Of the inner surface of the substrate main body 51, light that passes through the substrate main body 51 is scattered in a region that overlaps the reflective display region R in plan view and overlaps the pixel electrode 11 through the liquid crystal layer 23 in plan view. A scattering recess 51a is formed. When the substrate body 51 is made of glass, the scattering recess 51a is formed by partially performing an etching process using HF (hydrofluoric acid) on the surface of the substrate body 51. The scattering recess 51a is filled with a filler 51b made of a translucent material and having a refractive index different from that of the liquid crystal layer 23. A scattering region is constituted by the region of the substrate body 51 where the scattering recess 51a is formed.

The light shielding film 52 is formed in a region of the surface of the substrate body 51 that overlaps the edge of the sub pixel region in plan view, and borders the sub pixel region.
The color filter layer 53 is disposed corresponding to each sub-pixel region, and is made of, for example, acrylic and contains a color material corresponding to the color displayed in each sub-pixel region.
The alignment film 54 is made of a translucent resin material such as polyimide, and is provided so as to cover the color filter layer 53. The inner surface of the alignment film 54 is subjected to a rubbing process in the same direction as the alignment direction of the alignment film 36.

Since the liquid crystal molecules constituting the liquid crystal layer 23 are subjected to an alignment process in which the alignment layers 36 and 54 have the minor axis direction (Y-axis direction) of the sub-pixel region as the alignment direction, the pixel electrodes 11 and the common electrode 45 In a state where no voltage is applied between them (off state), the layers are oriented horizontally along the Y-axis direction. Further, the liquid crystal molecules are aligned along a direction orthogonal to the extending direction of the belt-like portion 11b in a state where a voltage is applied between the pixel electrode 11 and the common electrode 45 (on state). Therefore, in the liquid crystal layer 23, a phase difference is given to the light transmitted through the liquid crystal layer 23 by utilizing birefringence based on the difference in the alignment state of the liquid crystal molecules between the off state and the on state.
Here, the layer thickness of the liquid crystal layer 23 is a value such that the phase difference imparted to the light transmitted through the liquid crystal layer 23 in the reflective display region R becomes a quarter wavelength, and the liquid crystal layer 23 in the transmissive display region T. The phase difference imparted to the light that passes through is a value that corresponds to ½ wavelength.

The polarizing plate 24 is provided so that its transmission axis is along the major axis direction of the sub-pixel region (X-axis direction shown in FIG. 2), and the polarizing plate 25 is such that its transmission axis is the minor axis direction of the sub-pixel region. (Y-axis direction shown in FIG. 2) is provided. Accordingly, the polarizing plates 24 and 25 are provided so that their transmission axes are substantially orthogonal to each other.
Here, an optical compensation film (not shown) may be disposed inside one or both of the polarizing plates 24 and 25. By disposing the optical compensation film, it is possible to compensate for the phase difference of the liquid crystal layer 23 when the liquid crystal display device 1 is perspective, and to reduce light leakage and increase contrast. As the optical compensation film, a combination of a negative uniaxial medium and a positive uniaxial medium or a biaxial medium having a refractive index in each direction of nx>nz> ny is used.

[Operation of liquid crystal display device]
Next, the operation of the liquid crystal display device 1 having such a configuration will be described.
First, transmissive display (transmission mode) will be described. Light that has entered the transmissive display region T from the outer surface side of the element substrate 21 is converted into linearly polarized light parallel to the major axis direction (X-axis direction shown in FIG. 2) of the sub-pixel region by the polarizing plate 24 and enters the liquid crystal layer 23. Incident.
Here, in the off state, the linearly polarized light incident on the liquid crystal layer 23 is emitted from the liquid crystal layer 23 in the same polarization state as that upon incidence by the liquid crystal layer 23. The linearly polarized light has its polarization direction orthogonal to the transmission axis of the polarizing plate 25, and is thus blocked by the polarizing plate 25, and the sub-pixel region is darkly displayed.

  On the other hand, in the case of the on state, the linearly polarized light incident on the liquid crystal layer 23 is given a predetermined phase difference (1/2 wavelength) by the liquid crystal layer 23, and becomes linearly polarized light orthogonal to the polarization direction at the time of incidence. The light is converted and emitted from the liquid crystal layer 23. Since the polarization direction of the linearly polarized light is parallel to the transmission axis of the polarizing plate 25, the linearly polarized light passes through the polarizing plate 25 and is visually recognized as display light, and the sub-pixel region is brightly displayed.

Subsequently, reflection display (reflection mode) will be described. Light incident from the outer surface side of the counter substrate 22 is converted into linearly polarized light parallel to the minor axis direction (Y-axis direction shown in FIG. 2) of the sub-pixel region by the polarizing plate 25 and is incident on the liquid crystal layer 23.
Here, in the case of the off state, the linearly polarized light incident on the liquid crystal layer 23 is given a predetermined phase difference (for ¼ wavelength) by the liquid crystal layer 23, converted into circularly polarized light, and applied to the reflective film 44. Reach. When this circularly polarized light is reflected by the reflection film 44, the rotation direction is reversed. Thereafter, the circularly polarized light is further given a predetermined phase difference (for ¼ wavelength) by the liquid crystal layer 23, is converted into linearly polarized light orthogonal to the polarization direction at the time of incidence, and is emitted from the liquid crystal layer 23. The linearly polarized light has its polarization direction orthogonal to the transmission axis of the polarizing plate 25, and is thus blocked by the polarizing plate 25, and the sub-pixel region is darkly displayed.

On the other hand, in the case of the ON state, the linearly polarized light incident on the liquid crystal layer 23 reaches the reflection film 44 in the same polarization state as that upon incidence by the liquid crystal layer 23. The linearly polarized light reflected by the reflective film 44 is emitted from the liquid crystal layer 23 in the same polarization direction as that at the time of incidence. Thereafter, since the polarization direction of the linearly polarized light is parallel to the transmission axis of the polarizing plate 25, the linearly polarized light passes through the polarizing plate 25 and is visually recognized as display light, and the sub-pixel region becomes bright display.
Here, the light incident on the concavo-convex portion 44 a in the reflective film 44 is scattered and reflected and re-enters the liquid crystal layer 23 because the concavo-convex portion 44 a is a concavo-convex surface.
Further, the light incident on the flat portion 44 b in the reflective film 44 is specularly reflected and reenters the liquid crystal layer 23 because the flat portion 44 b is a flat surface. At this time, the specular reflected light mainly travels toward the region corresponding to the frame portion 11 a and the strip portion 11 b in the reflective display region R on the inner surface of the substrate body 51. The specular reflection light is scattered by the scattering recess 51a because the scattering recess 51a is formed in this region of the substrate body 51. Here, since the scattering recess 51a is formed only in the region corresponding to the frame portion 11a and the strip portion 11b in the reflective display region R on the inner surface of the substrate body 51, the scattered reflected light from the uneven portion 44a is scattered by the scattering recess. Excessive scattering by 51a is suppressed.
Thereby, regular reflection of external light in the on state is prevented, and a reflective display with excellent visibility is obtained. Moreover, light scattering by the scattering recess 51a is reliably performed by filling the scattering recess 51a with the filler 51b having a refractive index different from that of the liquid crystal layer 23.

〔Electronics〕
The liquid crystal display device 1 having the above configuration is applied as a display unit 101 of a mobile phone 100 as shown in FIG. The cellular phone 100 includes a main body 105 having a plurality of operation buttons 102, a mouthpiece 103, a mouthpiece 104, and the display unit 101.

As described above, according to the liquid crystal display device 1 and the mobile phone 100 in the present embodiment, the light reflected by the reflective film 44 is scattered by the scattering recess 51 a formed in the substrate body 51 corresponding to the reflective display region R. Therefore, the flat portion 44b is formed in the region of the surface of the reflective film 44 where the frame portion 11a and the strip-like portion 11b are formed, and the surface of the inner surface of the second interlayer insulating film 35 is formed. Of these, the region in which the frame portion 11a and the strip portion 11b are formed can be a flat portion 35b. Thereby, generation | occurrence | production of the disconnection of the strip-shaped part 11b, a short circuit with the other adjacent strip-shaped part 11b, etc. can be suppressed. Further, since the strip portion 11b can be more reliably patterned as designed, it is possible to prevent disturbance of the electric field generated between the pixel electrode 11 and the common electrode 45 and to drive the liquid crystal molecules more stably. it can.
Therefore, the display characteristics of the image in the reflective display (reflection mode) can be improved.

Here, the scattered reflected light reflected by the concavo-convex portion 44 a of the reflective film 44 is prevented from being excessively scattered by the scattering concave portion 51 a in the substrate body 51, and the brightness of the image by the reflective display region R is reduced. Can be suppressed.
Further, by forming the scattering recess 51 a on the same inner surface as the light shielding film 52 and the color filter layer 53 in the substrate body 51, the counter substrate 22 can be easily manufactured.
And since the inside of the scattering recessed part 51a is filled with the filler 51b from which the refractive index differs from the liquid crystal layer 23, the light scattering in the scattering recessed part 51a can be performed reliably.

[Second Embodiment]
Next, a liquid crystal display device according to a second embodiment of the present invention will be described with reference to the drawings. Here, FIG. 5 is a cross-sectional view showing the sub-pixel region. In this embodiment, since the configuration of the sub-pixel region is different from that of the first embodiment, this point will be mainly described, and the same reference numerals are given to the components described in the above embodiment, and the description will be given. Omitted.

In the liquid crystal display device 110 according to the present embodiment, as shown in FIG. 5, the liquid crystal layer thickness adjusting layer 34 is provided on the counter substrate 112 instead of the element substrate 111.
The liquid crystal layer thickness adjusting layer 34 is formed in a region corresponding to the reflective display region R on the inner surface of the color filter layer 53. The liquid crystal layer thickness adjusting layer 34 is made of a translucent resin material. The alignment film 54 is formed so as to cover the color filter layer 53 and the liquid crystal layer thickness adjusting layer 34.
The reflective film 44 is formed in a region corresponding to the reflective display region R on the inner surface of the first interlayer insulating film 33.
Of the inner surface corresponding to the reflective display region R of the first interlayer insulating film 33, the region overlapping the non-formed region of the pixel electrode 11 through the reflective film 44, the common electrode 45 and the second interlayer insulating film 35 in plan view. The convex part 113 is formed. The protrusion 113 is formed, for example, by patterning a resin material such as acrylic provided on the first interlayer insulating film 33. As a result, the uneven portion 44 a and the flat portion 44 b are formed in the reflective film 44. Here, the concavo-convex surface of the pixel electrode 11 passes through the reflective film 44, the common electrode 45, and the second interlayer insulating film 35 in plan view among the inner surface corresponding to the reflective display region R of the first interlayer insulating film 33. You may form by patterning the area | region which overlaps with a non-formation area | region.

  As described above, the liquid crystal display device 110 according to this embodiment also has the same operations and effects as described above.

[Third Embodiment]
Next, a liquid crystal display device according to a third embodiment of the present invention will be described with reference to the drawings. Here, FIG. 6 is a cross-sectional view showing the sub-pixel region. In this embodiment, since the configuration of the sub-pixel region is different from that of the first embodiment, this point will be mainly described, and the same reference numerals are given to the components described in the above embodiment, and the description will be given. Omitted.

  In the liquid crystal display device 120 according to the present embodiment, as shown in FIG. 6, a scattering recess 122 a is formed on the outer surface of the substrate body 122 constituting the counter substrate 121. The scattering recess 122a has an air layer inside and is not filled with a filler.

  As described above, the liquid crystal display device 120 according to this embodiment also has the same operations and effects as described above.

[Fourth Embodiment]
Next, a liquid crystal display device according to a fourth embodiment of the present invention will be described with reference to the drawings. Here, FIG. 7 is a cross-sectional view showing the sub-pixel region. In this embodiment, since the configuration of the sub-pixel region is different from that of the first embodiment, this point will be mainly described, and the same reference numerals are given to the components described in the above embodiment, and the description will be given. Omitted.

  In the liquid crystal display device 130 according to the present embodiment, as shown in FIG. 7, the counter substrate 131 includes a scattering plate 133 provided in a region corresponding to the reflective display region R on the outer surface of the substrate body 132. The scattering plate 133 is configured to scatter and emit incident light.

  As described above, the liquid crystal display device 130 according to this embodiment also has the same operations and effects as described above.

In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, the liquid crystal display device may have a configuration in which a scattering recess is formed on the outer surface of the substrate body of the counter substrate in the first embodiment as in the third embodiment. Similarly, a configuration in which a scattering plate is provided on the outer surface of the counter substrate may be employed. That is, the liquid crystal display device may have a configuration in which the configurations in the first, third, and fourth embodiments described above are appropriately combined, or the configurations in the second to fourth embodiments are appropriately combined.
Further, in the first to third embodiments, the liquid crystal display device has the scattering recesses formed only in the region corresponding to the frame portion and the strip electrode in the reflective display region in a plan view of the substrate body in the counter substrate. As long as the brightness of the image displayed by the reflective display region can be ensured, the reflective display region may be formed in another region including the region corresponding to the frame portion and the strip electrode. Similarly, in the fourth embodiment, the scattering plate may be provided only in a region where the scattering concave portion corresponds to the frame portion and the strip electrode in the reflective display region in a plan view of the substrate body in the counter substrate.
In the first to third embodiments, the liquid crystal display device is filled with the filler in the scattering recess. If the light can be reliably scattered in the reflective display (reflection mode), the liquid crystal display device scatters the filler. It is not necessary to fill the recess.

In addition, the pixel electrode connected to the TFT element is formed on the liquid crystal layer side with respect to the common electrode through the second interlayer insulating film, but the common electrode is formed on the liquid crystal layer with respect to the pixel electrode through the second interlayer insulating film. It is good also as a structure formed in the side. At this time, the common electrode has a strip-like electrode like the pixel electrode in the above embodiment.
The pixel electrode and the common electrode form an FFS electrode structure, but an IPS electrode structure may be formed. In this case, the pixel electrode and the common electrode each have a comb-like shape in plan view, and each has a strip portion (band electrode). Here, the belt-like portion constituting the pixel electrode and the belt-like portion constituting the common electrode are arranged so as to mesh with each other.
Furthermore, if the pixel electrode has a strip electrode, the electric field generated between the element substrate and the counter substrate sandwiching the liquid crystal layer is not limited to the so-called lateral electric field type liquid crystal display device such as the FFS method and the IPS method. Operates in other modes such as TN (Twisted Nematic) mode driven by VAN, VAN (Vertically Aligned Nematic) mode with negative dielectric anisotropy, ECB (Electrically Controlled Birefringence) mode, OCB (Optical Compensated Bend) mode A liquid crystal display device using liquid crystal may be used.

Further, the reflective display area and the transmissive display area are normally adjusted by adjusting the phase difference provided by the liquid crystal layer in the reflective display area by the liquid crystal layer thickness adjusting layer and the phase difference provided by the liquid crystal layer in the transmissive display area. Although the black mode is aligned, both display areas may be aligned in the normally black mode by providing a wavelength plate outside the element substrate without providing the liquid crystal layer thickness adjusting layer.
Here, the liquid crystal display device employs a normally black mode, but may employ a normally white mode.
The liquid crystal display device is a transflective liquid crystal display device having a reflective display region and a transmissive display region, but may be a reflective liquid crystal display device having only a reflective display region.

In addition, the liquid crystal display device uses a TFT element as a drive element for switching the pixel electrode. However, the present invention is not limited to the TFT element, and other drive elements such as a TFD (Thin Film Diode) element may be used. Good.
The liquid crystal display device is a color liquid crystal display device that performs color display of three colors of R, G, and B. However, the liquid crystal display device may include a sub-pixel region that performs other color display, and performs monochromatic color display. It is good also as a structure. Here, the color filter layer may be provided on the element substrate without providing the color filter layer on the counter substrate.

  In addition, the electronic device provided with the liquid crystal display device is not limited to a mobile phone, but a PDA (Personal Digital Assistant), a personal computer, a notebook personal computer, a workstation, a digital still camera, an in-vehicle monitor, a car Navigation device, head-up display, digital video camera, television receiver, viewfinder type or monitor direct-view type video tape recorder, pager, electronic notebook, calculator, electronic book or projector, word processor, video phone, POS terminal, touch panel It may be another electronic device such as a device provided, a lighting device, or the like.

  The electro-optical device is not limited to a liquid crystal display device as long as it changes the optical characteristics of the electro-optical layer by generating an electric field between a pair of electrodes and has a reflective display region. Other devices such as an organic EL (electroluminescence) device may be used.

1 is an equivalent circuit diagram illustrating a liquid crystal display device according to a first embodiment. It is a plane block diagram which shows a subpixel area | region. It is AA arrow sectional drawing of FIG. It is a schematic perspective view which shows a mobile telephone provided with a liquid crystal display device. It is a schematic sectional drawing which shows the sub pixel area | region in 2nd Embodiment. It is a schematic sectional drawing of the sub pixel area | region in 3rd Embodiment. It is a schematic sectional drawing of the sub pixel area | region in 4th Embodiment.

Explanation of symbols

1,110,120,130 Liquid crystal display device (electro-optical device), 11a Frame portion (band electrode), 11b Band portion (band electrode), 21,111 Element substrate (first substrate), 22, 112, 121, 131 Counter substrate (second substrate), 23 liquid crystal layer (electro-optic layer), 44 reflective film, 44a uneven portion, 44b flat portion, 51, 122, 132 substrate body, 51a, 122a scattering recess, 51b filler, 100 mobile phone (Electronic equipment) 133 Scattering plate

Claims (7)

An electro-optical device in which an electro-optical layer is sandwiched between first and second substrates and a reflective display region is provided in each pixel region,
A reflective film provided in the reflective display region of the first substrate;
A strip electrode provided on the reflective film,
The belt-like electrode is disposed on the electro-optic layer side of the reflective film, and at least a part thereof is formed on a flat surface in the reflective display region;
The reflective film has a concavo-convex portion provided in a region overlapping with the non-formation region of the belt-like electrode in a plan view, and a flat portion formed in a region overlapping with the belt-like electrode in a plan view,
An electro-optical device, wherein a scattering region that scatters light reflected by the reflective film is formed in a region of the reflective display region of the second substrate that overlaps with the strip electrode.   The electro-optical device according to claim 1, wherein the scattering region is formed only in a region overlapping with the belt-like electrode. The second substrate has a substrate body serving as a base,
The electro-optical device according to claim 1, wherein a scattering uneven portion is formed in the scattering region on the surface of the substrate body.   The electro-optical device according to claim 3, wherein the scattering uneven portion is formed on a surface of the substrate body on the electro-optical layer side.   The electro-optical device according to claim 3, wherein the scattering uneven portion is filled with a filler having a refractive index different from that of the electro-optical layer.   The electro-optical device according to claim 1, wherein a scattering plate is provided in the scattering region of the second substrate.   An electronic apparatus comprising the electro-optical device according to claim 1.

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