JP2001083494A - Semitransmission reflection type liquid crystal device and electronic appliance using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a bright and high-quality image for both of reflection-type display and transmission-type display in a semitransmission reflection type liquid crystal device without causing double reflection due to the parallax or blurred display. SOLUTION: The semitransmission reflection type liquid crystal device is equipped with a second insulation film 13, a semitransmission reflection electrode 11 having an opening, a first insulation film 12, and an alignment film 15 in this order formed on the liquid crystal layer 50 side of a first substrate 10. The film thickness and refractive index of each of the semitransmission reflection electrode, first insulation film and alignment film are determined to optimize the reflectance of the laminated body consisting of the semitransmission reflection electrode, first insulation film 12 and alignment film 15 in the reflection region. The film thickness and refractive index of the second insulation film 13 are determined to optimize the transmittance of the laminated body consisting of the second insulation film 13, first insulation film 12 and alignment film 15 in the transmission region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a liquid crystal device of a passive matrix drive system, an active matrix drive system, a segment drive system, and the like, and an electronic apparatus using the same. It belongs to the technical field of a transflective liquid crystal device adopting an internal reflection method provided with a reflective electrode layer and capable of switching between a reflective display and a transmissive display for display, and electronic equipment using such a liquid crystal device. .

[0002]

2. Description of the Related Art Conventionally, a reflection type liquid crystal device which performs display by using external light without using a light source such as a backlight is advantageous from the viewpoint of low power consumption, small size and light weight. The display can be viewed using a light source, and the display cannot be read in a dark place. Therefore, in a bright place, the outside light is used in the same way as a normal reflective liquid crystal device, and the display is viewed in a dark place by the internal light source. A transflective liquid crystal device of a possible type has been proposed. This is Shokai 5
As described in JP-A-7-049271, a polarizing plate, a transflective plate, and a backlight are sequentially arranged on the outer surface of the liquid crystal panel opposite to the observation side. In this liquid crystal device, when the surroundings are bright, external light is taken in and reflective display is performed using light reflected by the semi-transmissive reflecting plate. When the surroundings are dark, the backlight is turned on and the semi-transmissive reflecting plate is turned on. A transmissive display in which the display can be visually recognized by the light transmitted through is provided.

Another transflective liquid crystal device is disclosed in Japanese Unexamined Patent Publication No. Hei 8-292413 in which the brightness of a reflective display is improved.
Is described in Japanese Patent Application Publication No. In this liquid crystal device, the transflective plate, the polarizing plate, and the backlight are sequentially arranged on the outer surface of the liquid crystal panel opposite to the observation side, so that there is no polarizing plate between the liquid crystal cell and the transflective plate. A reflective display brighter than the liquid crystal device described in Japanese Utility Model Laid-Open No. 57-049271 can be obtained.

[0004]

However, in the transflective liquid crystal device described in JP-A-8-292413 or the like, a transparent substrate is interposed between the liquid crystal layer and the transflective plate. However, double reflection or blurring of display may occur. Further combining color filters,
Because the transflector is located behind the LCD panel,
Since a thick transparent substrate is interposed between the liquid crystal layer or the color filter and the semi-transmissive reflection plate, there is a problem that due to parallax, double reflection or blurring of display occurs, so that it is impossible to obtain a sufficient color.

On the other hand, Japanese Patent Application Laid-Open No. Hei 7-318929 proposes a transflective liquid crystal device in which a pixel electrode serving as a transflective film is provided on the inner surface of a liquid crystal cell. A configuration is disclosed in which a transparent pixel electrode made of an ITO film is stacked on a reflective film via an insulating film.
However, in this liquid crystal device, a fine defect such as a hole defect or a dent defect or a fine opening is formed with respect to a pixel electrode also serving as a transflective film or a transflective film on which a transparent pixel electrode is superimposed. It is necessary to provide a large number of devices, which complicates the device configuration and additionally requires special steps in its manufacture. In this liquid crystal device, on the other hand, it is possible to set the film thickness and the refractive index of each film constituting the laminate so as to increase the reflectance in the reflective display of the laminate formed on the substrate. On the other hand, it is possible to set the film thickness and the refractive index of each film constituting the laminate so as to increase the transmittance in the transmission type display of the laminate. It is generally almost impossible to optimize both at the same time (that is, there is generally no condition for each film and each refractive index that optimizes both at the same time). As a result, there is a problem in that it is difficult to realize a transflective liquid crystal device that enables both bright reflective display and bright transmissive display.

[0006] In addition, the present applicant has filed Japanese Patent Application No.
No. 656 and Japanese Patent Application No. 10-160866 each invent a novel transflective liquid crystal device. In the case of these liquid crystal devices as well, a reflective type liquid crystal device formed on a substrate is also used. It is generally almost impossible to simultaneously optimize both the reflectance at the time of display and the transmittance at the time of transmissive display, and the transflective type that enables both bright reflective display and bright transmissive display. There is a similar problem that it is difficult to realize a liquid crystal device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and does not cause double reflection or display bleeding due to parallax, and furthermore, realizes both a bright reflective display and a bright transmissive display. It is an object to provide a transflective liquid crystal device and an electronic device using the same.

[0008]

In order to solve the above problems, a transflective liquid crystal device according to the present invention comprises a transparent first substrate and a transparent second substrate opposed to the first substrate. A liquid crystal sandwiched between the first and second substrates, a light source provided on the first substrate on a side opposite to the liquid crystal, and a liquid crystal arranged on a side of the first substrate facing the second substrate. Transparent second
An insulating film, a reflective electrode layer provided on the second insulating film and provided with an opening for transmitting light from the light source, and a transparent first insulating film provided on the reflective electrode layer. A film, and an alignment film disposed on the first insulating film.

According to the transflective liquid crystal device of the present invention, on the first substrate is provided a laminate comprising a second insulating film, a reflective electrode layer, a first insulating film and an alignment film. Here, since the reflective electrode layer and the alignment film are insulated from each other by the first insulating film, the possibility of occurrence of defects such as electric leakage or short circuit with the counter electrode in the reflective electrode layer or its wiring is reduced. As a whole, the device reliability is improved.

According to the transflective liquid crystal device having such a configuration, when external light is incident from the second substrate side during reflective display, the external light is transmitted through the second substrate and the liquid crystal. The light is reflected by the reflective electrode layer (excluding the opening portion) and the laminated body including the first insulating film and the alignment film laminated thereon, and is again emitted from the second substrate side via the liquid crystal and the second substrate. You. Therefore, for example, if a polarizing plate is arranged on the outer surface side of the second substrate (that is, on the side opposite to the liquid crystal), the alignment state of the liquid crystal is controlled by applying an electric field using the reflective electrode layer, so that the liquid crystal is reflected through the liquid crystal after reflection. Thus, the intensity of external light emitted as display light can be controlled. That is, reflection type display can be performed.

On the other hand, at the time of transmissive display, when light from the light source is incident on the first substrate, the light from the light source is transmitted to the second insulating film, the first insulating film, and the alignment film located at the opening of the reflective electrode layer. The light passes through the film and is emitted from the second substrate side through the liquid crystal and the second substrate. Therefore, for example, if a polarizing plate is disposed on the outer surface side of the first substrate and the second substrate (that is, on the side opposite to the liquid crystal), the alignment state of the liquid crystal is controlled by applying an electric field using the reflective electrode layer. The light source light intensity emitted as display light via the liquid crystal after transmission can be controlled. That is, transmissive display can be performed.

Therefore, the film thickness and the refractive index of each of these films are set so as to increase the reflectivity of the laminated body composed of the reflective electrode layer, the first insulating film and the alignment film with respect to the incidence of external light from the liquid crystal. Under the condition that the film thickness and the refractive index set as described above are fixed, the transmittance of the laminated body including the second insulating film, the first insulating film, and the alignment film with respect to the source light transmitted from the first substrate to the liquid crystal is increased. In addition, it is possible to set the thickness and the refractive index of the second insulating film irrespective of external light reflection. In other words, by arranging the second insulating film between the first substrate and the reflective electrode layer, it is possible to optimize the reflectance in the reflective display independently of the second insulating film, By adjusting the thickness and the refractive index of the two insulating films, it is possible to optimize the transmittance in the transmission type display.

As a result of the above, according to the present invention, the above-mentioned conventional real opening and closing method can be used for both reflective display and transmissive display.
As described in Japanese Patent Application Laid-Open No. 049271 and Japanese Patent Application Laid-Open No. HEI 8-292413, when a color image is formed without the occurrence of double reflection or display bleeding due to the presence of the transparent substrate between the liquid crystal layer and the semi-transmissive reflector. In addition, a sufficient color can be obtained, and furthermore, a bright display can be performed in both the reflective display and the transmissive display.

The driving method of the transflective liquid crystal device of the present invention includes a passive matrix driving method and a TFT (Th.
in Film Transistor) Active matrix drive system,
Various known driving methods such as a TFD (Thin Film Diode) active matrix driving method and a segment driving method can be adopted. At this time, since the voltage-reflectance (transmittance) characteristics of the liquid crystal cell are often different between the reflective display and the transmissive display, the driving voltages are made different between the reflective display and the transmissive display, and It is preferable to optimize with. Further, a plurality of stripe-shaped or segment-shaped transparent electrodes are formed on the second substrate (counter substrate) as appropriate according to the driving method, or a transparent electrode is formed on almost the entire surface of the second substrate. Alternatively, without providing a counter electrode on the second substrate,
It may be driven by a horizontal electric field parallel to the substrate between pixel electrodes formed of a reflective electrode layer on the first substrate. Further, in the liquid crystal device, a polarizing plate, a retardation plate, and the like are respectively disposed on the outer surfaces of the first substrate and the second substrate according to the display method. Light sources illuminated during transmissive display include LED (Light Emitting Diode) elements and EL (El
An ectro-Luminescence element or the like is suitable, and for a large-sized liquid crystal device, a fluorescent tube or the like that introduces light from the side via a light guide plate is suitable.

In one embodiment of the transflective liquid crystal device of the present invention, the opening comprises a plurality of through holes formed in the reflective electrode layer.

According to this aspect, the reflective electrode layer is, for example,
A plurality of through holes such as square, rectangular, polygonal, and circular slits or regular or irregular fine holes are provided. Light is reflected, and at the time of transmissive display, light from the light source is transmitted through such a through hole. Therefore, as described above, while optimizing the reflectivity of the laminated body including the reflective electrode layer, the first insulating film, and the alignment film, the second insulating film (visible only in the through hole when viewed from the liquid crystal side) forms the second insulating film. Insulating film,
By optimizing the transmittance of the stacked body composed of the first insulating film and the alignment film, a bright display can be performed in both the reflective display and the transmissive display.

Alternatively, in another aspect of the transflective liquid crystal device of the present invention, the reflective electrode layer is formed of a plurality of reflective plates separated from each other when viewed two-dimensionally from a direction perpendicular to the second substrate. And the opening comprises a gap between the plurality of reflectors.

According to this aspect, the reflection electrode layer is, for example,
It comprises a plurality of striped or island-shaped reflectors (that is, pixel electrodes) divided for each unit to which an image signal is supplied. In a reflective display, external light is reflected by the plurality of reflectors and a transmissive display is performed. Sometimes, light from the light source is transmitted through a gap between the plurality of reflectors. Therefore, as described above, the reflective electrode layer,
While optimizing the reflectance of the stacked body composed of the first insulating film and the alignment film, the second insulating film (visible only from the gap between the plurality of reflectors when viewed from the liquid crystal side) has the second insulating film and the first insulating film. By optimizing the transmittance of the laminate composed of the film and the alignment film, a bright display can be performed both in the reflective display and the transmissive display. According to this aspect, in particular, the above-described conventional Japanese Patent Laid-Open No.
As in the transflective liquid crystal device described in Japanese Patent No. 318929, the transflective layer can be formed without providing a large number of fine defects and fine openings that may complicate the device configuration and manufacturing process. Therefore, it is practically advantageous, and it is also possible to improve device reliability and manufacturing yield.

In another aspect of the transflective liquid crystal device of the present invention, a phase difference plate is further provided between the light source and the first substrate.

According to this aspect, since the phase difference plate is provided, good display control can be performed in both the reflection type display and the transmission type display. More specifically, an optical element such as a polarizing plate and a retardation plate provided on the second substrate side reduces the influence on color tone such as coloring caused by wavelength dispersion of light during reflective display, and With the phase difference plate provided between the light source and the first substrate, it is possible to reduce the influence on the color tone such as coloring due to the wavelength dispersion of light during transmission display. Further, the optical characteristics of the polarizing plate, the retardation plate and the like, the liquid crystal and the reflective electrode layer provided on the second substrate side are set to enhance the contrast at the time of the reflective display, and under this condition, By setting the optical characteristics of the phase difference plate provided between the first substrate and the first substrate so as to increase the contrast in the transmissive display, high contrast characteristics can be obtained in both the reflective display and the transmissive display. .

In another aspect of the transflective liquid crystal device according to the present invention, the reflection of the reflection electrode layer, the first insulating film, and the alignment film from the liquid crystal side to light having a wavelength of about 550 nm is preferred. The thickness and the refractive index of the reflective electrode layer, the first insulating film, and the alignment film are set so that the refractive index becomes highest, and the wavelength 55 from the first substrate side is set.
Each of the second insulating film, the first insulating film, and the alignment film such that the transmittance of light near 0 nm of the stacked body including the second insulating film, the first insulating film, and the alignment film is highest. The film thickness and each refractive index are set.

According to this aspect, the wavelength 550 from the liquid crystal is obtained.
nm (that is, a wavelength corresponding to green light that is highly sensitive to human visual perception and is important for determining the brightness of a displayed image) of a reflective electrode layer, a first insulating film, and an alignment film. The reflectivity is optimized by the film thickness and the refractive index of each of these films, and at the same time, the light is transmitted from the first substrate to the liquid crystal under the conditions of the fixed film thickness and the refractive index so as to optimize the reflectivity. The thickness and refractive index of the second insulating film irrelevant to external light reflection, so as to optimize the transmittance of the laminated body including the second insulating film, the first insulating film, and the alignment film to light having a wavelength around 550 nm. Is set. Therefore, a very bright display can be made, especially in human vision, both in the reflection type display and the transmission type display.

In this aspect, the refractive index of the first insulating film is in the range of 1.4 to 1.6, and the refractive index of the second insulating film is different from the refractive index of the first insulating film. Different and 1.
It may be in the range of 4-1.6.

With this configuration, the reflectance for light near the wavelength of 550 nm in the reflective display is most easily increased in practical use, and the transmittance for light near the wavelength of 550 nm in the transmissive display is most easily increased. be able to. For example, the refractive index of a silicon oxide film is about 1.
46, and the refractive index of the Al (aluminum) oxide film is
It is about 1.7, and an insulating film having a desired refractive index between them can be formed as the first or second insulating film by using the sol-gel method.

In another embodiment of the transflective liquid crystal device of the present invention, the first and second insulating films each contain silicon oxide as a main component.

According to this aspect, since the transparent first and second insulating films containing silicon oxide as a main component may be formed, a relatively simple manufacturing process and a relatively low cost can be achieved.
The reflectance of the stacked body on the first substrate with respect to external light and the transmittance with respect to light from the light source can be increased.

According to another aspect of the invention, an electronic apparatus includes the above-described transflective liquid crystal device.

According to the electronic apparatus of the present invention, there is provided a transflective liquid crystal device capable of switching between bright reflective display and bright transmissive display without causing double reflection due to parallax or blurring of display. Various electronic devices such as a mobile phone, a wristwatch, an electronic organizer, and a notebook personal computer that are used can be realized.

The operation and other advantages of the present invention will become more apparent from the embodiments explained below.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

First Embodiment First, the structure of a liquid crystal device according to a first embodiment of the present invention will be described with reference to FIGS. In the first embodiment, the present invention is applied to a transflective liquid crystal device of a passive matrix driving system. FIG. 1 is a schematic plan view showing the liquid crystal device viewed from the counter substrate side with a color filter formed on the counter substrate removed for convenience, and FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1 is a schematic cross-sectional view of a liquid crystal device including a color filter. FIG. 3 is a schematic enlarged cross-sectional view showing, in an enlarged manner, a configuration near the transflective electrode plate shown in FIG. 2 that reflects external light and transmits light from a light source.
In FIG. 1, for convenience of explanation, the stripe-shaped electrodes are vertically and horizontally aligned.
Although each of them is shown schematically, there are actually a large number of electrodes. In FIGS. 2 and 3, each layer and each member are formed so as to be recognizable in the drawings. And the scale is different for each member.

Referring to FIGS. 1 and 2, the liquid crystal device according to the first embodiment includes a first substrate 10, a transparent second substrate 20 opposed to the first substrate 10, a first substrate 10 and a second substrate. The liquid crystal layer 50 sandwiched between the first substrate 10 and the first substrate 10
Side facing the second substrate 20 (that is, the upper surface in FIG. 2)
Second insulating film 13 disposed on the
A plurality of striped semi-transmissive reflective electrode plates 11 disposed thereon, a transparent first insulating film 12 disposed on the semi-transmissive reflective electrode plate 11, and an alignment film disposed on the first insulating film 12 15 is provided. The liquid crystal device also includes a color filter 23 disposed on a side of the second substrate facing the first substrate 10 (ie, a lower surface in FIG. 2), and a color filter flattening film disposed on the color filter 23. And a plurality of stripe-shaped transparent electrodes 21 arranged on the color filter flattening film 24 so as to intersect with the transflective electrode plate 11.
And an alignment film 25 disposed on the transparent electrode 21. The first substrate 10 and the second substrate 20 are bonded to each other around the liquid crystal layer 50 by a sealing material 31. The liquid crystal layer 50 is formed by the sealing material 31 and the sealing material 3.
2 encloses between the first substrate 10 and the second substrate 20. The liquid crystal device further includes a polarizing plate 107 and a retardation plate 108 on the opposite side of the first substrate 10 from the liquid crystal layer 50, and a polarizing plate 105 and a retardation plate on the opposite side of the second substrate 20 from the liquid crystal layer 50. A plate 106 is provided. Polarizing plate 107
Outside, a fluorescent tube 119 and a light guide plate 118 for guiding light from the fluorescent tube 119 from the polarizing plate 107 into the liquid crystal panel.
It is comprised including.

Here, the transflective electrode plate 11 in the present embodiment is a reflector provided with an opening such as a slit or a fine hole for transmitting the light source light from the first substrate 10 side. It also functions as a pixel electrode for driving liquid crystal.

That is, as shown in an enlarged manner in FIG. 3, the transflective electrode plate 11 is formed of Ag, Al, or the like, and transmits the light source light L2 from the first substrate 10 side in the transmissive area A2. Many openings 11a having a diameter of 2 μm are provided. The surface of the transflective electrode plate 11 is a reflection surface that reflects external light L1 incident from the second substrate 20 side in the reflection area A1 except for the opening 11a. Transmission area A
The openings 11a are provided randomly or regularly so that the total area of 2 is about 10% of the total area of the reflection area A1. Such a transflective electrode plate 11 is formed by vapor deposition, sputtering, or the like.

Referring again to FIGS. 1 and 2, the first substrate 10
The second substrate 20 is required to be transparent or at least translucent to visible light, and is made of, for example, a glass substrate or a quartz substrate.

Each of the alignment films 15 and 25 is made of an organic thin film such as a polyimide thin film, is formed by spin coating or flexographic printing, and has been subjected to a predetermined alignment process such as a rubbing process.

The liquid crystal layer 50 is in a predetermined alignment state by the alignment films 15 and 25 when no electric field is applied between the transflective electrode plate 11 and the transparent electrode 21. Liquid crystal layer 50
Is composed of, for example, a liquid crystal in which one or several kinds of nematic liquid crystals are mixed.

The sealing member 31 is an adhesive made of, for example, a photo-curing resin or a thermosetting resin. In particular, when the liquid crystal device is small, having a diagonal size of several inches or less, a gap material (spacer) such as glass fiber or glass beads is mixed into the sealing material to make the distance between the two substrates a predetermined value. You. However, such a gap material may be mixed in the liquid crystal layer 50 when the size of the liquid crystal device is several inches to 10 inches or more. The sealing material 32 is made of a resin adhesive or the like that seals the injection port after vacuum-injecting the liquid crystal through the injection port of the sealing material 31.

The color filter 23 includes a color material film that transmits blue light, green light and red light for each pixel, and a light shielding film called a black mask or a black matrix formed at the boundary of each pixel. Is a known color filter such as a delta arrangement, a stripe arrangement, a mosaic arrangement, and a triangle arrangement configured to prevent color mixing. Further, the light-shielding film may not be formed. FIG.
Although not shown in FIG. 2, a light-shielding film as a frame defining the periphery of an image display area made of the same or different material as the light-shielding film in the color filter 23 is provided in parallel with the inside of the sealing material 52. You may be. Alternatively, such a frame may be defined by an edge of a light-shielding case for housing the liquid crystal device.

The light guide plate 118 constituting a backlight together with the fluorescent tube 119 is a transparent body such as an acrylic resin plate having a scattering rough surface formed on the entire back surface or a scattering printing layer formed thereon. Is received at the end face, and substantially uniform light is emitted from the upper surface of the drawing.

Here, various specific examples of the opening 11a (see FIG. 3) of the transflective electrode plate 11 in this embodiment will be described with reference to FIG.

As shown in FIG. 4A, four rectangular slots may be arranged for each pixel as openings 11a in four directions, or as shown in FIG. 4B, four rectangular slots may be arranged for each pixel. The rectangular slots may be arranged side by side as openings 11a, a large number of circular openings may be discretely arranged as openings 11a for each pixel as shown in FIG. 4C, or FIG.
As shown, one relatively large rectangular slot may be arranged for each pixel as the opening 11a. The opening 11a is formed in a photo process using a resist / developing process /
It can be easily manufactured in a peeling step. Opening 11a
May be square, polygonal, elliptical, irregular, or slit-like extending over a plurality of pixels. In addition, it is possible to form the opening 11a at the same time as the patterning of the stripe-shaped transflective electrode plate 11 as shown in FIG. 1, so that the number of manufacturing steps does not need to be increased. In any shape, the diameter of the opening 11a is 0.01 μm or more and 20 μm or less, and the opening 11a has an area where the transmission area A2 is 5% or more and 30% or less with respect to the reflection area A1. Preferably, the openings are formed so as to have a ratio.

Incidentally, such a transflective electrode plate 11 is
When viewed two-dimensionally from the direction perpendicular to the second substrate 20, they are separated from each other, and the mutual gap becomes the transmission region A <b> 2 (that is, the liquid crystal portion facing this gap is formed by the oblique electric field generated by the transflective electrode plate 11). Drive). With such a configuration, the transflective electrode plate 11 can be configured without providing a large number of fine defects and fine openings that cause the device configuration and the manufacturing process to be complicated, which is practically advantageous. It is also possible to improve reliability and manufacturing yield.

Next, the operation of the transflective liquid crystal device of the first embodiment configured as described above will be described with reference to FIGS.
This will be described with reference to FIG.

First, the reflection type display will be described. In this case, when external light L1 is incident from the second substrate 20 side,
Through the second substrate 20 and the liquid crystal layer 50, the light is multiple-reflected by the laminate including the alignment film 15, the first insulating film 12, and the transflective electrode plate 11 provided on the first substrate 10 in the reflection area A 1, The light is again emitted from the second substrate 20 side via the liquid crystal layer 50 and the second substrate 20. Therefore, when an image signal and a scanning signal are supplied from an external circuit to the transflective electrode plate 11 and the transparent electrode 21 at a predetermined timing, the transflective electrode plate 11 and the transparent electrode 21 are provided at a portion where the transflective electrode plate 11 and the transparent electrode 21 intersect. , An electric field is sequentially applied to each row, each column, or each pixel. Thus, by controlling the alignment state of the liquid crystal layer 50 on a pixel-by-pixel basis, the external light L1 is modulated, and a gray scale display becomes possible.

Next, the transmission type display will be described. In this case, when the light source light L2 enters from below the first substrate 10, the second insulating layer provided on the first substrate 10 in the transmission area A2 (that is, the opening 11a of the transflective electrode plate 11). The light passes through the film 13, the first insulating film 12, and the alignment film 15, and is emitted from the second substrate 20 side via the liquid crystal layer 50 and the second substrate 20. Therefore, the transflective electrode plate 1 is provided from an external circuit.
When the image signal and the scanning signal are supplied to the first and the transparent electrodes 21 at a predetermined timing, the portion of the liquid crystal layer 50 where the transflective electrode plate 11 and the transparent electrode 21 intersect,
An electric field is sequentially applied to each row, each column, or each pixel.
Thus, by controlling the alignment state of the liquid crystal layer 50 for each pixel, the light source light L2 is modulated, and a gray scale display can be performed.

In the first embodiment which operates as described above, particularly, as shown in FIG.
A transflective electrode plate 11, a first insulating film 12, and an alignment film 15 for incidence of external light L1 having a wavelength of about 550 nm from zero.
The thickness and the refractive index of each of these films are set so as to optimize the reflectance R1 of the laminated body composed of. Then, under the condition that the film thickness and the refractive index set as described above are fixed, the second insulating film 13 for the light source light L2 having a wavelength of about 550 nm transmitted from the first substrate 10 to the liquid crystal layer 50 in the transmission region A2. The film thickness and the refractive index of the second insulating film 13 that are irrelevant to the reflection of the external light L1 in the reflection area A1 are set so as to optimize the transmittance T2 of the stacked body including the 1 insulating film 12 and the alignment film 15. You.

Next, a system in which a laminate composed of the first insulating film 12 and the alignment film 15 (two layers in total) formed on the transflective electrode plate 11 in the reflection area A1 faces the liquid crystal layer 50. , The reflectance R of the laminate to external light L1
1 and the laminated body composed of the second insulating film 13, the first insulating film 12, and the alignment film 15 (three layers in total) faces the first substrate 10 on the incident side and the emitting side in the transmission region A2. A description will be given of a simulation for obtaining the transmittance T2 of the stacked body with respect to the light source light L2 in the system facing the liquid crystal layer 50.

Simulation for obtaining reflectance R 1: here, transflective reflector 11, first insulating film 12
In addition, the reflectance R1 when the laminated body including the alignment film 15 is in the medium (the liquid crystal layer 50) is determined by the method of Rouard.

First, in general, the refractive index n ^* of an absorber such as a metal film or a semiconductor film is represented by a complex number as shown in the following equation.

N ^* = n-ik where n and k are optical constants of the absorbers These optical constants n and k are specific to each absorber and have wavelength dependence. It also changes depending on the film forming conditions. Therefore, once the absorber and its deposition conditions are determined,
It can be uniquely determined by empirical, experimental, or simulation. Here, FIG. 5 shows an example of a chart for obtaining optical constants n and k of aluminum constituting the transflective electrode plate 11 in the first embodiment.
Shown in

In FIG. 5, the wavelength of light (n
m) is shown, the optical constants n (left) and k (right) are shown on the vertical axis, the solid curve is the curve showing the wavelength dependence of the optical constant n, and the dotted curve is And a curve showing the wavelength dependence of the optical constant k. Therefore, for aluminum, for example, if the wavelength is 650 nm (red light), by following the intersection between the curve of the solid line and the wavelength of 650 nm as indicated by the arrow in the chart, n = 1.
3 is obtained. For example, if the wavelength is 700 nm, as indicated by the arrow in the chart, the dotted line curve and the wavelength 700 nm
By following the intersection with, the optical constants n and k can be easily obtained for any wavelength of light using the chart shown in FIG. 5, in a manner that k = 6.8 is obtained. The optical constants n and k for silver can be obtained in the same manner, and the value at a wavelength of 550 nm is n = 0.055.
And k = 3.32.

Next, the transflective electrode plate 11 (absorber) in the system in which the laminated body composed of the transflective electrode plate 11, the first insulating film 12, and the alignment film 15 faces the liquid crystal layer 50 in the present embodiment. ) Are defined as n and k, and the first insulating film 1
2 (dielectric) is defined as n ₂ and its film thickness is set as d.
₂ , the refractive index of the alignment film 15 (dielectric) is n ₁ , the film thickness is d _1, and the refractive index of the liquid crystal (medium) of the liquid crystal layer 50 is n ₀ . It is expressed by the following equation.

R = (r ₁ + r ₂ e ^-iθ1 + r ₃ e
_{^{-I (θ1 + θ2) + r}} 1 r 2 r 3 e -iθ2) / (1
^{_{+ R 1 r 2 e -iθ1 +}} r 1 r 3 e -i (θ1 + θ2)
⁺ _R 2 _r 3 ^e -iθ2) _{where, r 1 = (n 1 -n} 0) / (n 1 + n 0) r 2 = (n 2 -n 1) / (n 2 + n 1) r 3 = (n- n ₂ −ik) / (n + n ₂ −ik) θ ₁ = 4πn ₁ d ₁ / λ θ ₂ = 4πn ₂ d ₂ / λ Therefore, the energy reflectance R1 (=
The reflectance is obtained by substituting r ₁ , r ₂ , and r ₃ into the amplitude reflectance r, combining the denominator and numerator into a real term and an imaginary term, and multiplying the conjugate complex number.

Simulation for finding transmittance T2: In this case, transmittance T2 for source light L2
Instead of the first insulating film 1 in the transmission region A2.
3, a laminate comprising a first insulating film 12 and an orientation film 15 (three layers in total) facing the first substrate 10 on the incident side and facing the liquid crystal layer 50 on the exit side The relationship between the reflectance R2 for the light source light L2 and the film thickness of each layer and each refractive index will be obtained. Then, the transmittance T2 (= 1−R2) complementary to the reflectance R2 is immediately obtained. Therefore, the transmittance T2 (reflectance R2) can also be obtained by the same method as in the above-described simulation for obtaining the reflectance R1.

That is, here, three layers (the second insulating film 13, the first insulating film 12, and the alignment film 1) provided on the liquid crystal layer 50 are provided.
The reflectance R2 when the laminated body composed of 5) is in the medium (the first substrate 10) is determined by the method of Rouard.

First, the optical constants n and k of the liquid crystal constituting the liquid crystal layer 50 in the first embodiment are determined in the same manner as described with reference to FIG.
Ask for. Here, the liquid crystal layer 50 is made of a dielectric material (having no absorption).
Can be set to k = 0. Therefore, the optical constant of the liquid crystal layer 50 is determined only by n (refractive index).

Next, a liquid crystal in a system in which a laminated body in which the alignment film 15, the first insulating film 12, and the second insulating film 13 are stacked on the liquid crystal layer 50 in the transmission region A 2 faces the first substrate 10. The optical constants of the layer 50 are n and k (the refractive index of the liquid crystal layer 50 is n
, K = 0) and the refractive index of the first substrate 10 (medium) is n ₀ , and the amplitude reflectance r is expressed by the following equation. (However, in this case, in order from the lower layer, the second insulating film 1
Refractive index of 3 was the film thickness d ₁ with a n _1, the film thickness and d ₂ with the refractive index of the first insulating film 12 and n _2,
The refractive index of the alignment film 15 is set to n ₃ and the film thickness is set to d ₃ . _{) R = (r 1 + r} a e -iθ1) / (1 + r 1 r a e
^-Aishita1) _{However, r a = (r 2 +} r b e -iθ2) / (1 + r 2 r b e
^{_{-Iθ2) r b = (r 3}} + r c e -iθ3) / (1 + r 3 r c e
^−iθ3 ) r ₁ = (n ₁ −n ₀ ) / (n ₁ + n ₀ ) r ₂ = (n ₂ −n ₁ ) / (n ₂ + n ₁ ) r ₃ = (n ₃ −n ₂ ) / (n _{3 + n 2) r 4 =} (n-n 3 -ik) / (n + n 3 -ik) θ 1 = 4πn 1 d 1 / λ θ 2 = 4πn 2 d 2 / λ θ 3 = 4πn 3 d 3 / λ Therefore , The energy reflectivity R2 (= reflectance) is obtained by substituting the refractive index and the film thickness of each film into the above θ ₁ to θ ₃ and r _{1 to} r _4.
The first calculation, and then substituting these values from r _a r _b
Values sequentially calculate a, then calculates r by substituting r ₁ and r _a, it is obtained by multiplying the complex conjugate of r the resulting amplitude reflectance r. As a result, the transmittance T2
(= 1−R2) is obtained.

Using the above simulations, the reflectance R1 of the first insulating film 12 and the alignment film 15 can be obtained.
Are determined for optimizing (i.e., maximizing) the refractive index R2 in the second insulating film 13 which does not affect the reflectance R1 under these conditions. The conditions of the film thickness (that is, the lowest) and the refractive index are determined.

FIGS. 6 to 8 show the relationship between the reflectance R2 obtained by the simulation as described above and the thickness and the refractive index of the second insulating film 13. FIG. Here, the reflectance (R2) of the laminated body with respect to light having a wavelength of 550 nm corresponding to green light, which is sensitive to human vision and is important in determining the brightness of a display image, is determined. It is as follows.

The refractive index of the liquid crystal layer 50 = 1.6 The refractive index of the alignment film 15 = 1.65 The thickness of the alignment film 15 = 30.0 nm The optical thickness of the alignment film 15 = 50.1 Refractive index = 1.60: FIG. 6 = 1.54: FIG. 7 = 1.46: FIG. 8 Thickness of first insulating film 12 = 90.0 nm Optical thickness of first insulating film 12 = 144.0: In the case of FIG. 6 = 138.6: In the case of FIG. 7 = 131.4: In the case of FIG. 8, and the refractive index of the second insulating film 13 is 1 as shown in FIGS. The thickness of the second insulating film 13 was changed to 50 nm, 75 nm, and 10
For each of 0 nm, the reflectance R2 is obtained by simulation.

As shown in FIGS. 6 to 8, the first insulating film 1
Even if the refractive index or the film thickness of the second insulating film 13 is changed, the reflectance R2 is made sufficiently low by changing the refractive index of the second insulating film 13 (that is, the transmittance T2 in the transmission type display is made sufficiently high). Is possible).

In particular, as shown in FIG. 6, when the refractive index of the first insulating film 12 is 1.60, the refractive index of the second insulating film 13 is almost independent of the thickness of the second insulating film 13. Is about 1.
Within the range of 50 to 1.60, the reflectance R2 can be minimized. That is, by adjusting only the refractive index without adjusting the thickness of the second insulating film 13, the reflectance R2 (transmittance T2) can be easily optimized.

As shown in FIG. 7, when the refractive index of the first insulating film 12 is 1.54, the refractive index of the second insulating film 13 is almost independent of the thickness of the second insulating film 13. When the reflectance is in the range of about 1.45 to 1.55, the reflectance R2 can be minimized. That is, by adjusting only the refractive index without adjusting the thickness of the second insulating film 13, the reflectance R2 (transmittance T2) can be easily optimized.

Further, as shown in FIG. 8, when the refractive index of the first insulating film 12 is 1.46, the minimum value of the reflectance R 2 slightly depends on the thickness of the second insulating film 13. The refractive index of the second insulating film 13 that gives a minimum value (that is, optimizes the reflectance R2) is in the range of about 1.40 to 1.50. Thickness dependence is low. That is, without adjusting the thickness of the second insulating film 13,
By adjusting only the refractive index, the reflectance R2 (transmittance T2) in a practical sense can be easily optimized.

It is assumed that the second insulating film 13 is formed in the transmission area A2.
Is not present, the first substrate 10 and the first insulating film 12
When these optical characteristics are set so as to optimize the reflectance R1, the reflectance R2 increases due to the difference in the refractive index between the two (that is, the transmission R2). In many cases, the reflectance T2 is lowered), and there is almost no possibility that at least the reflectance R2 (transmittance T2) is accidentally optimized. However, according to the present embodiment, by arranging the second insulating film 13 having a different refractive index from the first insulating film 12 in the transmission region A2, the thickness and refraction of the second insulating film 13 are independent of the reflectance R1. Since the rate can be adjusted, the reflectance R2 can be reduced (that is, the transmittance T2 can be increased).

In this embodiment, the first insulating film 12 and the second
Each of the insulating films 13 includes, for example, silicon oxide as a main component so as to satisfy the above-described conditions, and has a refractive index of liquid crystal of 1.6.
The refractive index of the first insulating film 12 and the refractive index of the second insulating film 13 are different from each other with respect to 0 and 1.65 of the refractive index of the alignment film 15 and each have a value within a range of about 1.4 to 1.6. ing. With this configuration, the reflectance R1 for light near the wavelength of 550 nm in the reflective display is most easily increased practically, and at the same time, the wavelength 550 nm in the transmissive display is obtained.
The transmittance T2 for the nearby light can be maximized. For example, a silicon oxide film has a refractive index of about 1.46, and an Al (aluminum) oxide film has a refractive index of about 1.46.
7, an insulating film having a desired refractive index between the two can be formed as the first insulating film 12 or the second insulating film 13 by using the sol-gel method. In this case, as the first substrate 10, for example, an alkali-free glass substrate having a refractive index of about 1.54 or soda glass having a refractive index of about 1.52 to 1.55 may be used.

The thickness of the alignment film 15 may be set to, for example, about 10 to 80 nm so as to function well as the alignment film. For example, 1
What is necessary is just to set to 0-300 nm.

As described above, according to the present embodiment, the wavelength 5
The reflectance R1 in the reflective display for light near 50 nm (that is, a wavelength corresponding to green light that is highly sensitive to human vision and is important for determining the brightness of a display image) is optimized, and at the same time, the transmissive type is used. Since the transmittance T2 in the display is also optimized, a very bright display can be obtained, especially in human vision, both in the reflective display and the transmissive display.

Further, according to the present embodiment, the transflective electrode plate 1 on the upper side of the first substrate 10 is compared with the conventional liquid crystal device that reflects light by the reflector provided outside the first substrate.
1. Since external light is reflected by multiple reflection by the laminated body including the first insulating film 12 and the alignment film 15, parallax in a display image is reduced and brightness in the display image is improved by the shortened optical path.

In addition, if the transflective electrode plate 11 and the alignment film 15 were formed on the first substrate 10 without the interposition of the first insulating film 12, especially in the liquid crystal layer 50 or in the sealing material When conductive foreign matter having a size larger than the gap material (spacer) in the liquid crystal layer 31 enters the liquid crystal layer 50, the liquid crystal layer 50 breaks the alignment films 15 and 25 and
1 and the transparent electrode 21 are short-circuited, that is, there is a high possibility that a device defect occurs. However, according to the first embodiment, the occurrence of such a device defect is caused by the presence of the first insulating film 12 having a higher strength than the alignment film 15 or by the cooperation between the alignment film 15 and the first insulating film 12. The probability can be significantly reduced.

In the first embodiment, as described above, the first insulating film 12 and the second insulating film 13 are mainly composed of silicon oxide, and the reflection plate 14 is mainly composed of aluminum. The reflectance can be improved with a simple manufacturing process and at a relatively low cost. However, even if the main component of the reflection plate 14 is another metal such as silver or chromium, the effects of the first embodiment as described above can be obtained.

In the first embodiment described above, the first insulating film 12 and the second insulating film 13 preferably contain inorganic oxide particles having an average particle size of 50 nm or less. With this configuration, the alignment film 15 formed on the first insulating film 12
And the first insulating film 12 formed on the second insulating film 13 are improved, so that the liquid crystal device can be manufactured relatively easily and the device reliability can be improved. Such inorganic oxide particles are composed of, for example, silicon oxide particles, aluminum oxide particles, tin oxide particles, indium oxide particles, and the like. It can be contained.

In the first embodiment described above, the terminal portion of the transflective electrode plate 11 extended to the terminal region on the first substrate 10 and the transparent electrode 21 extended to the terminal region of the second substrate 20. For example, TAB (Tape Autom
A driving LSI that is mounted on a substrate and includes a data line driving circuit and a scanning line driving circuit for supplying an image signal and a scanning signal to the transflective electrode plate 11 and the transparent electrode 21 at a predetermined timing is used. The connection may be made electrically and mechanically via an isotropic conductive film. Alternatively, the first substrate 10 or the second substrate 2 outside the sealing material 31
Such a data line driving circuit or a scanning line driving circuit may be formed in a peripheral region on the pixel 0 to form a so-called liquid crystal device with a built-in driving circuit. A so-called peripheral circuit built-in type liquid crystal device may be formed by forming an inspection circuit or the like for inspecting quality, defects and the like.

On the outer surface of the first substrate 10 or the second substrate 20, for example, a TN (Twisted Nematic) mode, V
A (Vertically Aligned) mode, PDLC (Polymer Dis
A polarizing film, a retardation film, a polarizing plate, and the like are arranged in a predetermined direction according to an operation mode such as a persed liquid crystal (persed liquid crystal) mode and a normally white mode / normally black mode. Further, a micro lens may be formed on the first substrate 10 or the second substrate 20 so as to correspond to one pixel. In this case, a bright liquid crystal device can be realized by improving the efficiency of collecting incident light.
Furthermore, by depositing a number of interference layers having different refractive indexes on the second substrate 20, RG can be utilized by utilizing light interference.
A dichroic filter for producing the B color may be formed. According to the counter substrate with the dichroic filter, a brighter color liquid crystal device can be realized.

Next, the polarizing plate 10 according to the first embodiment will be described.
5, retardation plate 106, polarizing plate 107 and retardation plate 108
The optical setting (see FIG. 2) will be described with reference to FIGS.

In the first embodiment, the phase difference plate 106 reduces the influence on the color tone such as coloring caused by the wavelength dispersion of light in the reflection type display (ie, the reflection type display using the phase difference plate 106 In addition, the phase difference plate 108 reduces the influence on the color tone such as coloring caused by the wavelength dispersion of light in the transmission type display (that is, the phase difference plate 106 reduces the influence on the reflection type display). Under the condition of optimizing the display, it is possible to further optimize the display in the transmissive display by the phase difference plate 108). In addition, it is also possible to arrange a plurality of retardation plates 106 and 108 by color compensation of a liquid crystal cell or viewing angle compensation, respectively. As described above, if a plurality of retardation plates are used as the retardation plates 106 or 108, optimization of coloring compensation or visual compensation can be more easily performed.

Further, the polarizing plate 105 and the retardation plate 10
6. The optical characteristics of the liquid crystal layer 50 and the transflective electrode plate 11 are set so as to enhance the contrast at the time of reflective display, and the optical characteristics of the polarizing plate 107 and the phase difference plate 108 at the time of the transmissive display under this condition. By setting the contrast to be high, high contrast characteristics can be obtained in both the reflective display and the transmissive display. For example, during reflective display, external light passes through the polarizing plate 105 to become linearly polarized light, and further passes through the phase difference plate 106 and the liquid crystal layer 50 in a voltage non-applied state (dark display state) to become right circularly polarized light. Then, the light reaches the transflective electrode plate 11, where the light is reflected, the traveling direction is reversed, the light is converted into left-handed circularly polarized light, and is again converted into linearly-polarized light through the liquid crystal layer 50 portion where no voltage is applied. 105
The polarizer 105 is absorbed by (ie, darkens)
Phase difference plate 106, liquid crystal layer 50 and transflective electrode plate 11
Is set. At this time, since external light passing through the liquid crystal layer 50 in the voltage applied state (bright display state) passes through the liquid crystal layer 50, the transflective electrode plate 11
And is emitted from the polarizing plate 105 (ie, becomes brighter). On the other hand, at the time of the transmissive display, the light source light emitted from the backlight and transmitted through the opening 11a of the transflective electrode plate 11 via the polarizing plate 107 and the phase difference plate 108 is partially reflected at the time of the above-mentioned reflective display. Transmission / reflection electrode plate 1
The optical characteristics of the polarizing plate 107 and the retardation plate 108 are set so that the light becomes the same as the left circularly polarized light reflected at 1.
Then, although the light source and the optical path are different from those in the reflective display, the transflective electrode plate 1 in the transmissive display is provided.
The light from the light source passing through the first opening 11a passes through the portion of the liquid crystal layer 50 in a voltage non-applied state (dark display state) similarly to the external light reflected on the transflective electrode plate 11 during the reflective display. The light is converted into polarized light and absorbed by the polarizing plate 105 (that is, darkened). At this time, light that passes through the liquid crystal layer 50 in the voltage applied state (bright display state) passes through the liquid crystal layer 50 and is emitted from the polarizing plate 105 (ie, becomes brighter).

As described above, the polarizing plate 105, the retardation plate 106, the liquid crystal layer 50, the transflective electrode plate 11, the polarizing plate 107, and the retardation plate capable of obtaining high contrast characteristics in both the reflection type display and the transmission type display. Two specific examples of the optical characteristics of the plate 108 are shown in FIGS.
In FIG. 9 and FIG. 10, the five stacked rectangles respectively indicate a liquid crystal cell including the polarizing plate 105, the retardation plate 106, the liquid crystal layer 50, and the respective layers of the retardation plate 108 and the polarizing plate 107 in order from the top. , And the axial direction is indicated by arrows drawn in each rectangle. 9 and 10, the upper retardation plate 106 of the liquid crystal cell is composed of two retardation plates (hereinafter referred to as a first retardation plate 106a and a second retardation plate 106b). Further, in the example shown in FIG. 10, the lower retarder 108 of the liquid crystal cell is composed of two retarders (the third retarder 108a and the fourth retarder 10a).
8b).

In FIG. 9, the absorption axis 13 of the polarizing plate 105 is shown.
01 is 35.5 degrees to the left with respect to the longitudinal direction of the panel. The delay axis direction 1302 of the first retardation plate 106a is 102.5 degrees to the left with respect to the longitudinal direction of the panel, and its retardation is 455 nm. The delay axis direction 1303 of the second retardation plate 106b is at the left 48.
5 degrees and the retardation is 544 nm. The rubbing direction 1304 of the alignment film on the transparent substrate 20 side of the liquid crystal cell is 37.5 degrees to the right with respect to the longitudinal direction of the panel. Rubbing direction 1305 on the transparent substrate 10 side of the liquid crystal cell
Is 37.5 degrees left with respect to the longitudinal direction of the panel. The liquid crystal is rotated counterclockwise from the transparent substrate 20 toward the transparent substrate 10.
Twisted 55 degrees. The product of the birefringence Δn of the liquid crystal and the cell gap d is 0.90 μm. Phase difference plate 1
08 is 10.5 degrees to the right with respect to the panel longitudinal direction, and its retardation is 140 nm.
It is. The absorption axis 1307 of the polarizing plate 107 is 49.5 degrees to the left with respect to the longitudinal direction of the panel. Under this condition, the light emitted from the backlight is a green light having a wavelength of 560 nm, in an elliptically polarized state having an ellipticity of 0.85, and an opening of the transflective electrode plate 11 arranged in the liquid crystal cell. 11a. The rotation direction is clockwise, and the polarizer 1
The polarization state is substantially the same as that of the external light that is incident from the side 05 and passes through the liquid crystal layer in the dark display state and is reflected by the transflective electrode plate 11. Therefore, if the optical characteristics are set as in this example, high contrast characteristics can be obtained in both the reflective display and the transmissive display.

In FIG. 10, the absorption axis 1 of the polarizing plate 105 is shown.
Reference numeral 401 denotes left 110 degrees with respect to the panel longitudinal direction. The delay axis direction 1402 of the first retardation plate 106a is 127.5 degrees to the left with respect to the longitudinal direction of the panel, and the retardation is 270 nm. The delay axis direction 1403 of the second retardation plate 106b is 10 degrees to the left with respect to the longitudinal direction of the panel, and the retardation is 140 nm. Rubbing direction 140 of alignment film on transparent substrate 20 side of liquid crystal cell
4 is 51 degrees to the right with respect to the panel longitudinal direction. The rubbing direction 1405 on the transparent substrate 10 side of the liquid crystal cell is at left 50 degrees with respect to the panel longitudinal direction. The liquid crystal is a transparent substrate 2
It is twisted 79 degrees clockwise from 0 toward the transparent substrate 10. The product of the birefringence Δn of the liquid crystal and the cell gap d is 0.24 μm. The delay axis direction 1406 of the third retardation plate 108a is 100 degrees to the left with respect to the longitudinal direction of the panel, and its retardation is 140 nm. The delay axis direction 1407 of the fourth retardation plate 108b is 37.5 degrees to the left with respect to the longitudinal direction of the panel, and its retardation is 270 nm. Absorption axis 140 of polarizing plate 108
Reference numeral 8 denotes left 20 degrees with respect to the panel longitudinal direction. Under this condition, the light emitted from the backlight has a wavelength of 560
The opening 11a of the transflective electrode plate 11 arranged in the liquid crystal cell in a relatively wide wavelength range centered on green light of nm and having an ellipticity of 0.96 at the maximum in an elliptically polarized state close to circularly polarized light. Pass through. The rotation direction is counterclockwise, and the polarization state is substantially the same as the external light that enters from the polarizing plate 105 side, passes through the liquid crystal layer in the dark display state, and is reflected by the transflective electrode plate 11. Therefore, if the optical characteristics are set as in this example, high contrast characteristics can be obtained in both the reflective display and the transmissive display.

As described above with reference to FIGS. 9 and 10, the liquid crystal device of the present invention includes the polarizing plate 105 and the retardation plate 106, and the polarizing plate 107 and the retardation plate 108, so that the reflection type display is performed. It is possible to obtain good color compensation and high contrast characteristics in both of the transmission type display and the transmission type display. The setting of these optical characteristics is not limited to those illustrated in FIGS. 9 and 10, but may be performed experimentally, theoretically, or by simulation.
The setting can be made in accordance with the brightness and contrast ratio required in the specification of the liquid crystal device.

In the first and second embodiments, the surface of the transflective electrode plate 11 facing the liquid crystal layer 50 is made uneven so that the mirror surface is eliminated and the surface is made to appear as a scattering surface (white surface). You may do so. The viewing angle may be widened by scattering due to unevenness. This uneven shape can be formed by using a photosensitive acrylic resin or the like for the base of the transflective electrode plate 11 and the second insulating film 13 or by roughening the base substrate itself with hydrofluoric acid. .
Note that a transparent flattening film (insulating film) is formed on the uneven surface of the transflective electrode plate 11 so that the surface facing the liquid crystal layer 50 (the surface on which the alignment film is formed) is flattened. This is desirable from the viewpoint of preventing poor alignment of the polymer.

(Second Embodiment) Next, a second embodiment of the liquid crystal device according to the present invention will be described with reference to FIGS. In the second embodiment, the present invention is applied to a TFD active matrix driving type transflective liquid crystal device.

First, the configuration near the TFD drive element used in the present embodiment will be described with reference to FIGS. FIG. 11 is a plan view schematically showing a TFD driving element together with a pixel electrode and the like.
FIG. 12 is a sectional view taken along the line BB ′ of FIG. 11. In FIG. 12, the scale of each layer and each member is made different so that each layer and each member have a size recognizable in the drawing.

Referring to FIGS. 11 and 12, the TFD drive element 40 is formed on a second insulating film 13 formed on a TFD array substrate 10 ', which is another example of the first substrate, as a base. The first metal film 42, the insulating layer 44, and the second metal film 46 are arranged in this order from the side of the second insulating film 13, and have a TFD structure or an MIM structure. And T
The first metal film 42 of the FD drive element 40 is connected to a scanning line 61 formed on the TFD array substrate 10 ′,
The second metal film 46 is connected to the pixel electrode 62.
Note that a data line (to be described later) is replaced with a TFD instead of the scanning line 61.
The scanning lines 61 may be formed on the array substrate 10 ', connected to the pixel electrodes 62, and provided on the counter substrate side.

The TFD array substrate 10 ′ is made of, for example, an insulating and transparent substrate such as glass or plastic. As described above, in the present embodiment, the second insulating film 1
3 also functions as a base film of the TFD element 40, but an insulating film dedicated to the base film different from the second insulating film 13 may be formed of tantalum oxide or the like, or the surface of the TFD array substrate 10 '. If there is no problem in the state, such a base film can be omitted. The first metal film 42 is made of a conductive metal thin film, for example, tantalum alone or a tantalum alloy. The insulating film 44 is made of, for example,
It consists of an oxide film formed on the surface of the metal film 42 by anodic oxidation. The second metal film 46 is made of a conductive metal thin film,
For example, it is composed of chromium alone or a chromium alloy.

In this embodiment, in particular, the pixel electrode 62 is formed on the second insulating film 13 similarly to the transflective electrode plate 11 provided with the opening 11a (see FIG. 4) in the first embodiment. And an opening 62a such as a slit or a fine hole made of a reflective and conductive metal film such as Al.
Is provided. In the second embodiment, the pixel electrodes 62 may be formed in an island shape slightly smaller than each pixel region, and the gap between the pixel electrodes 62 may function as a light transmission region in each pixel region. Good.

Further, the pixel electrode 62, the TFD driving element 4
The first insulating film 12 is provided on the side facing the liquid crystal (the upper surface in the figure), such as the scanning line 61 and the scanning line 61, and the alignment film 15 is provided thereon as in the case of the first embodiment. ing.

The TFD drive element has been described as a two-terminal type nonlinear element. However, a ZnO (zinc oxide) varistor, an MSI (Metal Semi-Insulator) drive element, an RD
A two-terminal nonlinear element having bidirectional diode characteristics such as (Ring Diode) can be applied to the liquid crystal device of the present embodiment.

Next, the configuration and operation of the liquid crystal device of the TFD active matrix driving system according to the second embodiment, which is provided with the TFD driving elements configured as described above, will be described with reference to FIGS. explain. here,
FIG. 13 is an equivalent circuit diagram showing a liquid crystal element together with a driving circuit, and FIG. 14 is a partially cutaway perspective view schematically showing the liquid crystal element.

Referring to FIG. 13, in the liquid crystal device of the TFD active matrix drive system, a plurality of scanning lines 61 arranged on a TFD array substrate
0, and a plurality of data lines 71 arranged on the opposite substrate are connected to the X driver circuit 110. The Y driver circuit 100 and the X driver circuit 1
10 may be formed on the TFD array substrate 10 'or its counter substrate, or may be an external I / O independent of the liquid crystal device.
C, and may be connected to the scanning lines 61 and the data lines 71 via predetermined wiring.

In each pixel region of the matrix, the scanning line 61 is connected to one terminal of the TFD drive element 40 (see FIGS. 11 and 12), and the data line 71 is connected to the liquid crystal layer 50 and the pixel electrode 62. Through the TFD drive element 40
Is connected to the other terminal. Therefore, a scanning signal is supplied to the scanning line 61 corresponding to each pixel region, and the data line 7 is supplied.
When the data signal is supplied to the pixel region 1, the TFD driving element 40 in the pixel region is turned on, and a driving voltage is applied to the liquid crystal layer 50 between the pixel electrode 62 and the data line 71 via the TFD driving element 40. You.

In FIG. 14, the liquid crystal device includes a TFD array substrate 10 ′ and a transparent second substrate (opposite substrate) 20 disposed opposite to the TFD array substrate 10 ′.

The second substrate 20 has a plurality of data lines 7 extending in a direction intersecting the scanning lines 61 and arranged in a strip shape.
1 is provided. The alignment film 25 is provided below the data line 71. The data line 71 is, for example, ITO
It is made of a transparent conductive thin film such as a film. In FIG. 14, optical elements such as a light source and a polarizing plate are omitted.

As described above, the TF of the second embodiment
According to the D active matrix driving type liquid crystal device,
Each pixel electrode 62 is provided between the pixel electrode 62 and the data line 71.
By sequentially applying an electric field to the liquid crystal portions, the alignment state of each liquid crystal portion can be controlled, and the intensity of external light or light source emitted as display light via each liquid crystal portion can be controlled. Here, similarly to the case of the first embodiment, in the reflection region of each pixel electrode 62, the alignment film 15, the first insulating film 12, and the pixel electrode 62 are formed in this order from the liquid crystal layer 50 side. Is set so as to optimize the reflectance with respect to external light incident from the liquid crystal layer 50, so that a high reflectance can be obtained at the time of reflective display. Moreover, in the transmission region, the second insulating film 1 is sequentially arranged from the TFD array substrate 10 'side.
3, the first insulating film 12 and the alignment film 15 are formed,
Since the transmittance for the light from the light source is optimized by using the second insulating film 13 irrelevant to the reflectance, a high transmittance can be obtained even in the transmission type display. In particular, since power is supplied to each pixel electrode 62 through the TFD 40, the pixel electrode 62
Crosstalk between them can be reduced, and higher-quality image display can be performed.

(Third Embodiment) Next, a third embodiment of the liquid crystal device according to the present invention will be described with reference to FIGS. In the third embodiment, the present invention is applied to a transflective liquid crystal device of a TFT active matrix driving system. FIG. 15 is an equivalent circuit of various elements, wiring, and the like in a plurality of pixels formed in a matrix forming an image display area of the liquid crystal device. FIG. 16 is a diagram in which data lines, scanning lines, pixel electrodes, and the like are formed. FIG. 17 is a plan view of a plurality of pixel groups adjacent to each other on the TFT array substrate shown in FIG.
FIG. 17 is a sectional view taken along the line CC ′ of FIG. 16. In FIG. 17, in order to make each layer and each member have a size recognizable in the drawing, the scale is different for each layer and each member.

In FIG. 15, in the liquid crystal device of the TFT active matrix system of the third embodiment, the pixel electrode 62
Are formed in a matrix, and a data line 135 to which an image signal is supplied is electrically connected to a source of the TFT 130. Image signals S1, S2,..., Sn to be written to the data lines 135
May be supplied line-sequentially in this order, or may be supplied to a plurality of adjacent data lines 135 for each group. Further, the scanning line 131 is electrically connected to the gate of the TFT 130, and the scanning signals G1 and G are pulsed to the scanning line 131 at a predetermined timing.
, Gm are applied line-sequentially in this order. The pixel electrode 62 is electrically connected to the drain of the TFT 130 and has a switching element T
By opening the switch of the FT 130 for a certain period, the image signals S1 and S1 supplied from the data line 135 are output.
2, ..., Sn are written at a predetermined timing. The image signals S1, S2,..., Sn of a predetermined level written in the liquid crystal via the pixel electrodes 62 are held for a certain period of time between the counter electrodes after the switch of the TFT 130 is closed. Here, in order to prevent the held image signal from leaking, a storage capacitor 170 is added in parallel with a liquid crystal capacitor formed between the pixel electrode 62 and the counter electrode.

In FIG. 16, a matrix of pixel electrodes 62 (the outline 62a is indicated by a dotted line in the figure) is provided on the TFT array substrate.
Data line 135, scan line 1 along the vertical and horizontal boundaries of
31 and a capacitance line 132 are provided. Data line 13
Reference numeral 5 is electrically connected to the source region of the semiconductor layer 1a made of a polysilicon film or the like via the contact hole 5. The pixel electrode 62 is electrically connected to the drain region of the semiconductor layer 1a via the contact hole 8. The capacitance line 132 is opposed to the first storage capacitance electrode extending from the drain region of the semiconductor layer 1a via the insulating film, and forms the storage capacitance 170. In addition, the scanning line 131 is arranged so as to face the channel region 1a 'indicated by the hatched region in the semiconductor layer 1a which rises to the right in the figure, and the scanning line 131 functions as a gate electrode.
As described above, at the intersections of the scanning lines 131 and the data lines 135, the TFTs 130 in which the scanning lines 131 are opposed to each other as gate electrodes in the channel region 1a 'are provided.

As shown in FIG. 16, the liquid crystal device includes a TFT array substrate 10 ″, which constitutes another example of the first substrate, and a transparent second substrate (opposite substrate) 20 disposed opposite to the TFT array substrate 10 ″. ing.

In this embodiment, in particular, the TFT array substrate 1
The pixel electrode 62 provided at 0 ″ is formed on the second insulating film 13 like the transflective electrode plate 11 provided with the opening 11a (see FIG. 4) in the first embodiment. An opening 62a such as a slit or a fine hole is formed of a reflective and conductive metal film such as Al. In the third embodiment, the pixel electrode 62 is formed in an island shape slightly smaller than each pixel region. And the pixel electrode 62
The gap between them may function as a light transmitting area in each pixel area.

On the side facing the liquid crystal, such as the pixel electrode 62 and the TFT 130 (upper surface in the figure), the first insulating film 12 and the alignment film 15 are provided as in the case of the first embodiment.

On the other hand, a counter electrode 121 as another example of a transparent electrode is provided on almost the entire surface of the second substrate 20, and a non-opening region of each pixel is called a black mask or a black matrix. The second light shielding film 122 is provided. An alignment film 25 is provided below the counter electrode 121.

On the TFT array substrate 10 ″, a pixel switching TFT 130 for controlling switching of each pixel electrode 62 is provided at a position adjacent to each pixel electrode 62.

As described above, the pixel electrode 62 and the counter electrode 121
And the TFT array substrate 10 "
Liquid crystal is sealed in a space surrounded by the sealing material between the first substrate and the second substrate 20 as in the first embodiment, and a liquid crystal layer 50 is formed.

Furthermore, a plurality of pixel switching TFTs 1
Below the 30, a first interlayer insulating film 112 is provided. The first interlayer insulating film 112 functions as a base film for the TFT 30 by being formed on the entire surface of the TFT array substrate 10.

In FIG. 17, a TF for pixel switching is used.
T130 is connected to the data line 13 via the contact hole 5.
5, a channel region 1 a ′ opposed to the scanning line 131 via a gate insulating film, and a drain region connected to the pixel electrode 62 via a contact hole 8. The scanning line 131 is A
It is composed of a light-shielding and conductive thin film such as a low-resistance metal film such as 1 or an alloy film such as metal silicide. Also,
A second interlayer insulating film 114 having contact holes 5 and 8 formed thereon is formed thereon, and a third interlayer insulating film 1 having contact holes 8 formed therein is further formed thereon.
17 are formed.

The pixel switching TFT 130 is an LD
The TFT may have any structure such as a D structure, an offset structure, and a self-aligned structure. In addition to single gate structure, T
The FT 130 may be configured.

As described above, the TF of the third embodiment
According to the liquid crystal device of the T active matrix drive system,
Each pixel electrode 6 is provided between the pixel electrode 62 and the counter electrode 121.
By sequentially applying an electric field to the liquid crystal portion in 2,
The alignment state of each liquid crystal portion can be controlled, and the intensity of external light or light source light emitted as display light via each liquid crystal portion can be controlled. Here, similarly to the case of the first embodiment, in the reflection region of each pixel electrode 62, the alignment film 15, the first insulating film 12, and the pixel electrode 62 are formed in this order from the liquid crystal layer 50 side. Is set so as to optimize the reflectance with respect to external light incident from the liquid crystal layer 50, so that a high reflectance can be obtained during the reflective display. Moreover, in the transmission region, the second insulating film 13, the first insulating film 12, and the alignment film 15 are formed in this order from the TFT array substrate 10 ″ side, and the second insulating film 13 irrespective of the reflectance is used. Therefore, since the transmittance with respect to the light from the light source is optimized, a high transmittance can be obtained even in the transmission type display.
, Power is supplied to each pixel electrode 62, so that crosstalk between the pixel electrodes 62 can be reduced, and higher-quality image display can be performed.

(Fourth Embodiment) Next, a liquid crystal device according to a fourth embodiment of the present invention will be described with reference to FIG. The fourth embodiment includes various electronic devices to which the transflective liquid crystal devices according to the first to third embodiments of the present invention described above are applied.

First, the liquid crystal device according to the first to third embodiments is connected to, for example, a mobile phone 10 as shown in FIG.
When applied to the display unit 1001 of 00, an energy-saving mobile phone that is bright and has high contrast in both reflective display and transmissive display, and that performs high-definition monochrome or color display with almost no parallax can be realized.

A wristwatch 1 as shown in FIG.
When applied to the display unit 1101 of 100, an energy-saving wristwatch that is bright and has high contrast in both reflective display and transmissive display, and that performs high-definition monochrome or color display with almost no parallax can be realized.

Further, in a personal computer (or information terminal) 1200 as shown in FIG. 18C, a display screen 120 provided in a cover which can be opened and closed on a main body 1204 with a keyboard 1202 is provided.
Applying to No. 6, an energy-saving personal computer that is bright and has high contrast in both reflective display and transmissive display and that performs high-definition monochrome or color display with almost no parallax can be realized.

In addition to the electronic apparatus shown in FIG. 18, a liquid crystal television, a viewfinder type or a monitor direct-view type video tape recorder, a car navigation system, an electronic organizer, a calculator, a word processor, an engineering workstation (EWS), Videophone, POS terminal,
Electronic devices such as devices with touch panels, etc.
Accordingly, the transflective liquid crystal device of the third embodiment can be applied.

The present invention is not limited to the embodiments described above, but can be implemented by appropriately changing the embodiments without departing from the spirit of the present invention.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a passive matrix driving type liquid crystal device according to a first embodiment of the present invention viewed from a counter substrate side with a color filter formed on the counter substrate removed for convenience. .

FIG. 2 is a schematic cross-sectional view of the liquid crystal device showing a cross section taken along line AA ′ of FIG. 1 including a color filter.

3 is a schematic enlarged cross-sectional view showing, in an enlarged manner, a configuration in the vicinity of the transflective electrode plate shown in FIG. 2 that reflects external light and transmits light from a light source.

FIG. 4 is an enlarged plan view showing various specific examples of an opening provided in the transflective electrode plate of the first embodiment.

FIG. 5 is a characteristic diagram showing an example of a chart for obtaining optical constants n and k of aluminum constituting the transflective electrode plate in the first embodiment.

FIG. 6 is a characteristic diagram (part 1) showing the relationship between the reflectance in the transmission region and the thickness and the refractive index of the second insulating film, obtained by simulation in the first embodiment.

FIG. 7 is a characteristic diagram (part 2) showing the relationship between the reflectance in the transmission region and the thickness and the refractive index of the second insulating film, obtained by simulation in the first embodiment.

FIG. 8 is a characteristic diagram (part 3) showing the relationship between the reflectance in the transmission region and the thickness and the refractive index of the second insulating film, obtained by simulation in the first embodiment.

FIG. 9 is a conceptual diagram showing an example of a preferable optical characteristic setting pattern in the first embodiment.

FIG. 10 is a conceptual diagram showing another example of a setting pattern of a suitable optical characteristic in the first embodiment.

FIG. 11 is a plan view schematically showing a TFD drive element used in a TFD active matrix drive type liquid crystal device according to a second embodiment of the present invention, together with pixel electrodes and the like.

FIG. 12 is a sectional view taken along line B-B 'of FIG.

FIG. 13 is an equivalent circuit diagram showing an equivalent circuit of a pixel portion of a liquid crystal device according to a second embodiment together with a peripheral driving circuit.

FIG. 14 is a partially broken perspective view schematically showing a liquid crystal device according to a second embodiment.

FIG. 15 is an equivalent circuit diagram of a pixel portion of a liquid crystal device of a TFT active matrix drive system according to a third embodiment of the present invention.

FIG. 16 is a plan view of a pixel portion of a liquid crystal device according to a third embodiment.

FIG. 17 is a sectional view taken along line C-C ′ of FIG. 16;

FIG. 18 is an external view of various electronic devices according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... 1st substrate 11 ... Transflective electrode plate 11a ... Opening 12 ... 1st insulating film 13 ... 2nd insulating film 15 ... Alignment film 20 ... 2nd substrate 25 ... Alignment film 31 ... Sealing material 32 ... Sealing material

Continued on the front page F-term (Reference) 2H090 HA03 HA04 HA08 HB03X HB06X HB17X HD04 HD06 HD08 JA06 JA09 LA04 LA06 LA20 2H091 FA08X FA08Z FA15Y FA37Y FB06 FB13 FD08 FD10 GA02 GA06 GA07 GA13 KA01 KA02 LA03 LA17 2B07 JA07 GA03 JB56 KB25 NA01 PA12

Claims (8)

[Claims] A transparent first substrate; a transparent second substrate opposed to the first substrate; a liquid crystal sandwiched between the first and second substrates; and a liquid crystal of the first substrate. A light source provided on a side opposite to the first substrate, a transparent second insulating film disposed on a side of the first substrate facing the second substrate, and a light source disposed on the second insulating film and from the light source. A reflective electrode layer provided with an opening through which the light is transmitted, a transparent first insulating film disposed on the reflective electrode layer, and an alignment film disposed on the first insulating film. A transflective liquid crystal device, characterized in that: 2. The transflective liquid crystal device according to claim 1, wherein the opening comprises a plurality of through holes formed in the reflective electrode layer. 3. The reflective electrode layer includes a plurality of reflectors separated from each other when viewed in a plan view from a direction perpendicular to the second substrate, and the opening is formed from a gap between the plurality of reflectors. The transflective liquid crystal device according to claim 1, wherein: 4. The transflective liquid crystal device according to claim 1, further comprising a retardation plate between the light source and the first substrate. 5. The reflective electrode layer, the reflective electrode layer, and the second conductive layer, wherein the reflective electrode layer, the first insulating film, and the alignment film have the highest reflectance with respect to light near the wavelength of 550 nm from the liquid crystal side. 1 The thickness and the refractive index of each of the insulating film and the alignment film are set, and the second insulating film, the first insulating film, and the alignment film for light having a wavelength of about 550 nm from the first substrate side. The thickness and refractive index of each of the second insulating film, the first insulating film, and the alignment film are set so that the transmittance of the stacked body becomes highest. 3. The transflective liquid crystal device according to claim 1. 6. The refractive index of the first insulating film is 1.4 to 1.4.
The refractive index of the second insulating film is different from the refractive index of the first insulating film and is in a range of 1.4 to 1.6. 6. The transflective liquid crystal device according to 5. 7. The semiconductor device according to claim 1, wherein each of the first and second insulating films contains silicon oxide as a main component.
3. The transflective liquid crystal device according to claim 1. 8. An electronic apparatus comprising the transflective liquid crystal device according to claim 1. Description: