JP2001350151A - Liquid crystal display device and portable terminal or display device equipped with the liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make excludable a void in the case of a normally black displaying. SOLUTION: The liquid crystal display device 21 comprises a dot matrix displaying part 22 and an icon displaying part 23. Data electrodes 24 for the icon displaying and a signal electrode 14 are formed on a transparent substrate 9 and a dummy pattern 25 is provided on the periphery of the data electrodes 24 for the icon displaying. Also a reflection layer 16 and a color filter layer 17 are successively laminated on a transparent substrate 10 and a common electrode 26 for the icon displaying and scanning electrodes 19 are formed on the color filter layer 17. Furthermore, the dummy pattern 25 and the common electrode 26 for the icon displaying are made to be in electrical conduction states and made to have the same potential.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having an icon display section and a dot matrix display section in a display area. Further, the present invention relates to a portable terminal and a display device provided with the liquid crystal display device of the present invention.

[0002]

2. Description of the Related Art In an information terminal such as a mobile phone, a personal information terminal or an order entry terminal, a liquid crystal display device is used as a display panel. In addition to a normal display area (dot matrix display section), An icon display section for displaying a power-on state, an operation mode, a specific message, and the like is also provided.

According to such information terminals, particularly in portable terminals, low power consumption is required for liquid crystal display devices.

For example, using a reflection type liquid crystal display device,
A technique for reducing power consumption by operating the dot matrix display unit by time division driving and operating the icon display unit by static driving and displaying only the icon display unit in a standby state has been proposed. Kaihei 11-2
No. 81961).

However, the above-mentioned reflection type liquid crystal display device is an external type in which the reflection plate is disposed outside the liquid crystal panel. Therefore, the transparent liquid crystal panel constituting the liquid crystal panel is provided between the reflection plate and the liquid crystal layer. A double image was generated by the interposition of the substrate and the reflection of incident light on the transparent substrate in addition to the light reflected by the reflector.

[0006] In addition, in the conventional portable terminal, a reflection type monochrome liquid crystal display device has been mainstream, but in recent years, with the increase in the amount of information, the trend of colorization has been increasing.

However, when a reflection type color liquid crystal display device using a color filter is used, since a reflection plate is an external type, a thick transparent substrate exists between the color filter and the reflection plate. Then, the light passing through one pixel of the color filter is reflected by the reflector, and again,
Even though the light passed through the one pixel, the optical path was long. Therefore, there is a problem that a shift occurs between the incident light and the reflected light with respect to the color filter, and the luminance, brightness, and color purity are reduced.

Therefore, in order to solve such a problem,
A technique has been proposed in which a reflective layer is provided on the inner surface of a transparent substrate in place of an externally mounted reflector (see Japanese Patent Application Laid-Open No. Hei 8-201802).

Hereinafter, this technique will be described with reference to FIGS. FIG. 4 is a plan view schematically showing the liquid crystal display device 1 and has a configuration common to both monochrome and color types. FIG. 5 is a sectional view showing an example of a color liquid crystal display device 2 provided with a color filter.

In the liquid crystal display device 1 shown in FIG. 4, an icon display section 3 and a dot matrix display section 4 are provided on a display screen.
The icon display unit 3 is a so-called pictogram display unit. For example, in a mobile phone, a reception sensitivity display unit 5 that displays the reception sensitivity of an antenna and a battery that displays the remaining capacity of a built-in battery are provided. A capacity display unit 6 is provided.

The dot matrix display section 4 is a simple matrix type display system, and is composed of a striped X electrode group 7 as a signal electrode and a striped Y electrode group 8 as a scanning electrode. The electrode groups 7 and 8 are opposed to each other while being orthogonal to each other.

The intersection (dot) between the X electrode group 7 and the Y electrode group 8 becomes each pixel.
During the period 8, a drive voltage is applied to a predetermined dot, and ON / OFF is performed by not applying the voltage, thereby turning on or off each pixel.
Information (data) such as abbreviated telephone numbers, transmission dial numbers, and message information is displayed.

In the liquid crystal display device 1 provided with the above-described icon display unit 3 and dot matrix display unit 4, a specific colorized configuration will be described with reference to a color liquid crystal display device 2 shown in FIG.

Two transparent substrates 9 and 10 are arranged so as to face each other, and a liquid crystal layer 11 is sealed between them by a sealing material 12 arranged in a frame to form a liquid crystal cell.

On the inner surface of the transparent substrate 9, a common electrode 13 for displaying an icon and a signal electrode 14 for a dot matrix display (corresponding to the X-electrode group 7 in a stripe shape) are formed by ITO or the like. An alignment film (not shown) is formed thereon, and rubbed in a predetermined direction.

A polarizing plate 15 is provided on the outer surface of the transparent substrate 9.
Are arranged. Instead of the polarizing plate 15, a polarizing film or a retardation film may be provided.

On the other hand, in the transparent substrate 10, a conductive light-reflective or light-semitransmissive layer (hereinafter, abbreviated as a reflective layer 16) made of a metal such as Al, Cr, or Ag, and a color A filter layer 17 is sequentially stacked, and on this color filter layer 17, an icon display data electrode 18 made of ITO or the like and a scanning electrode 19 (dotted Y electrode group 8) for a dot matrix display are formed. Is formed. Note that the signal electrodes 14 and the scanning electrodes 19 of the dot matrix display section are arranged so as to be orthogonal to each other.

An alignment film (not shown) is formed on the data electrode 18 for icon display and the scanning electrode 19 for the dot matrix display.

Thus, the color liquid crystal display device 2 having the above configuration
According to this, an icon display section and a dot matrix display section are provided on a display screen, the icon display section is driven statically, and the dot matrix display section is driven in a time-division manner.

In order to display an image on the dot matrix display section, a voltage is applied between the signal electrode 14 and the scanning electrode 19, and a driving voltage is applied to each dot, whereby the liquid crystal layer 11 is formed.
, An electric field is generated and turned on / off, and information (data) such as message information is displayed.

[0021]

However, according to the liquid crystal display device 2 having the above structure, the reflective layer 16 provided under the scanning electrode 19 for the dot matrix display is made of a conductive material, so that the electric power is reduced. The icon display section is statically driven, and a predetermined voltage is always applied to the icon display common electrode 13, so that the icon display section has an inherent electrode. An electric field is generated between the reflective layer 16 and the icon display common electrode 13 even in a non-existent area (hereinafter, referred to as an icon background section 20). There is a problem in that white spots are seen in the case of the marily black display, and that it looks as if it is lit blackish in the case of the normally white display.

In addition, in the liquid crystal display device 2 as described above, the cell gap d in the icon background portion 20
₁ (the distance between the common electrode 13 for icon display and the color filter 17) and the cell gap d in the icon display section
₂ (the distance between the icon display common electrode 13 and the icon display data electrode 18), there is a difference between them, and the retardations Δnd ₁ and Δn
d ₂ (Δn; birefringence of liquid crystal) is different.
The compensation conditions by the polarizing plate and the retardation film are shifted,
When no voltage is applied, a phenomenon in which white spots appear in the icon background portion 20 has appeared.

The present invention has been completed in view of the above description, and its purpose is to eliminate the occurrence of white spots in the case of normally black display on the background of the icon display section, or to turn on blackish in normally white display. It is an object of the present invention to provide a high-performance reflective or semi-transmissive liquid crystal display device that eliminates such a phenomenon as appears.

Another object of the present invention is to provide a high-performance portable terminal or display device equipped with the liquid crystal display device of the present invention.

[0025]

According to the liquid crystal display device of the present invention, one substrate and the other substrate are disposed via a nematic liquid crystal layer, and a dot matrix display portion and an icon display portion are formed. A conductive reflective layer or a semi-transmissive layer is formed thereon, one of the stripe-shaped transparent electrode groups corresponding to the dot matrix display section is formed thereon, and a common electrode is formed corresponding to the icon display section. An alignment film is coated on the stripe-shaped transparent electrode group and the common electrode, and the other stripe-shaped transparent electrode group is orthogonal to the one stripe-shaped transparent electrode group on the other substrate corresponding to the dot matrix display portion. And a data display electrode corresponding to the icon display portion, and a dummy pattern energized with the common electrode, and the other stripe-shaped transparent electrode group and the data display electrode. Characterized by comprising coating the alignment layer on the electrode and the dummy patterns.

Further, a portable terminal according to the present invention is characterized by including the liquid crystal display device according to the present invention.

Further, a display device of the present invention is characterized in that the liquid crystal display device of the present invention is provided.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Liquid Crystal Display Device of the Present Invention) The present invention will be described with reference to a color liquid crystal display device shown in FIGS.

FIG. 1 is a schematic plan view of a liquid crystal display device showing an arrangement of a dot matrix display section and an icon display section on a display screen, FIG. 2 is a sectional view thereof, and FIG. It is. Note that the same portions of the liquid crystal display device shown in FIGS. 4 and 5 are denoted by the same reference numerals.

In the liquid crystal display device 21 shown in FIG.
Reference numeral 0 denotes a transparent substrate as the one substrate, and 9 denotes a transparent substrate as the other substrate.
For example, a liquid crystal layer 11 made of a chiral nematic liquid crystal twisted at an angle of 200 to 270 ° is sealed with a frame-shaped sealing material 12 to form a liquid crystal cell.

In such a liquid crystal cell, a dot matrix display section 22 and an icon display section 23 are formed.

On the inner surface of the transparent substrate 9, a data electrode 24 for icon display and a signal electrode 14 for a dot matrix display, which is the other stripe-shaped transparent electrode group, are formed by ITO or the like. And a dummy pattern 25 around the icon display data electrode 24.
Is provided. Further, an icon display data electrode 24,
An alignment film (not shown) made of a polyimide resin or the like is formed on the signal electrode 14 and the dummy pattern 25, and rubbing is performed in a predetermined direction.

The polarizing plate 15 is provided on the outer surface of the transparent substrate 9.
TN (twisted nematic) mode, STN (super TN) mode, D-ST
They are arranged in a predetermined direction according to an operation mode such as an N (double-STN) mode or a normally white mode / normally black mode. In addition, you may use a polarizing film, a retardation film, etc. instead of this polarizing plate.

On the other hand, on the inner surface of the transparent substrate 10, Al,
A conductive light-reflective or light-semitransmissive layer (hereinafter abbreviated as “reflective layer 16”) made of a metal such as Cr or Ag or an alloy thereof (hereinafter abbreviated as “reflective layer 16”) and a color filter layer 17 are sequentially laminated. A common electrode 26 for displaying icons made of ITO or the like and a scanning electrode 19 for a dot matrix portion, which is one of the stripe-shaped transparent electrode groups, are formed on 17. Signal electrode 14 for the dot matrix section and scanning electrode 1 for the dot matrix section
9 are arranged orthogonally.

The reflective layer 8 is made of a conductive metal such as Al, Cr, Ag or the like, and is made substantially light-reflective by increasing its thickness, or semi-transparent by reducing its thickness. Further, the reflective layer 8 may be specular or scattering, and in order to provide scattering, an uneven shape is provided by a resin or the like, and a conductive reflective layer is formed thereon. can get.

Further, an alignment film (not shown) made of a polyimide resin or the like is formed on the common electrode 26 for displaying icons and the scanning electrode 19 for the dot matrix portion.

In the present invention, as shown in FIG. 3, the dummy pattern 25 and the common electrode 26 for displaying an icon are not electrically conductive, and both have the same potential.
For this purpose, for example, the sealing material 12 is made of a conductive material, and the dummy pattern 25 and the common electrode 2 for icon display are used.
6 may be extended to just below or directly above the sealing material 12, respectively, and electricity may be passed through the sealing material 12. Alternatively, if the conductive sealing material 12 is not used, a conductive material such as an Ag paste may be separately provided in the liquid crystal layer 11 and electric current may be supplied using the conductive material. Further, the same voltage may be directly applied to both the dummy pattern 25 and the common electrode 26 for icon display from the outside.

As shown in FIG. 1, a pictogram display section 27 (for example, in a portable telephone, a reception sensitivity display section for displaying the reception sensitivity of an antenna, and a remaining capacity of a built-in battery are displayed by an icon display data electrode 24). And a dummy pattern 25 (hatched portion) surrounds the pictogram display portion 27 (icon display data electrode 24).

Thus, according to the liquid crystal display device 21 of the present invention, the dummy pattern 25 is formed by the common electrode 2 for displaying icons.
6, the electric field is no longer applied to the liquid crystal layer 11, the white spot is eliminated in the case of the normally black display, and the problem of turning on blackish in the normally white display is not caused. .

In addition, the icon display data electrode 24
And the dummy pattern 25 provided therearound,
The cell gap becomes equal over substantially the entire surface of the icon display section 23, and thus, the phenomenon that the background of the icon becomes blank when no voltage is applied as in the related art does not occur. (Mobile Phone of the Present Invention) A mobile phone 28 equipped with the liquid crystal display device 21 will be described with reference to FIG. According to the mobile phone 28, the liquid crystal display device 21 is disposed in a small housing 29. The liquid crystal display device 21 includes a dot matrix display unit 22 and an icon display unit 23 in a display area. . A transmitting / receiving antenna 30 is provided on an upper portion of the housing 29, and a receiver 31 and a microphone 32 are provided on the surface.
Are formed.

The reflective layer 16 is formed of a light-reflective or semi-transmissive layer. When the reflective layer 16 is light-reflective, the liquid crystal display device 21 becomes a reflective liquid crystal display device. When the reflection layer 16 is translucent, the liquid crystal display device 21 is a transflective liquid crystal display device. (Portable Terminal of the Present Invention) A portable terminal 33 provided with the liquid crystal display device 21 will be described with reference to FIG. The mobile terminal 33 is shown as various information terminals other than the mobile phone 28. For example, watches, calculators, game consoles, pedometers,
Examples include, but are not limited to, GPS, POS, handy terminals, and industrial instruments.

Also in this portable terminal 33, the liquid crystal display device 21 is disposed in a small casing 34, and the liquid crystal display device 21 has a dot matrix display section 2 in a display area.
2 and an icon display unit 23.

When the reflection layer 16 is light-reflective, the liquid crystal display device 21 becomes a reflection type liquid crystal display device,
When the reflection layer 16 is translucent, the liquid crystal display device 21 is a transflective liquid crystal display device. (Semi-Transmissive Liquid Crystal Display) A case where the liquid crystal display 21 of the present invention is a transflective liquid crystal display will be described with reference to FIG.

A retardation plate 35 made of polycarbonate or the like and an iodine-based polarizing plate 36 are sequentially stacked on the outer surface of the transparent substrate 9 of the liquid crystal panel, and a retardation plate 37 made of polycarbonate or the like and an iodine The polarizing plates 38 of the system are sequentially stacked. These are attached using an adhesive made of an acrylic material.

Further, a backlight 39 is provided on the polarizing plate 38. In the backlight 39, a light source 41 such as a cold cathode tube or an LED is disposed on an end face of the light guide plate 40, and the light emitted from the light source 41 is introduced into the light guide plate 40, and the light guide plate 40 emits light to the liquid crystal panel.

In a liquid crystal panel, a signal electrode 14 and an alignment film (not shown) made of a polyimide resin rubbed in a certain direction are provided on a transparent substrate 9 such as a glass substrate.
Are sequentially formed. An insulating layer made of SiO2 or the like may be interposed between the signal electrode 14 and the alignment film.

A semi-transmissive film 42 is formed on the inner surface of the transparent substrate 10 such as a glass substrate, and the color filter 17 is provided on the semi-transmissive film 42. Further color filter 1
A thin film made of a metal such as aluminum or chromium or a black matrix which is a light-shielding film formed of a photosensitive resist may be formed between the light-emitting elements 7.

Then, on the color filter 17, SiO
2 and an overcoat layer 43 made of a resin, the scan electrode 19 and an alignment film (not shown) made of a polyimide resin rubbed in a certain direction on the overcoat layer 43.
Are sequentially formed. This scanning electrode 19 is orthogonal to the signal electrode 14. An insulating layer made of SiO2 or the like may be provided between the scanning electrode 19 and the alignment film.

The transflective film 42 has both light transmissive and light reflective properties, and prevents a phase difference from occurring when sandwiched between two polarizing plates. In addition, the semi-transmissive film 42 may be specular or scattering.
In order to produce the semi-transmissive film 42 having a scattering property, a semi-transparent film may be formed thereon by forming an irregular shape with a resin.

The color filter 17 is of a pigment dispersion type,
That is, a photosensitive resist prepared in advance with a pigment (red, green, blue, or the like) is applied on a substrate and formed by photolithography.

Each of the transparent substrates 9 and 10 thus formed
Are bonded by a sealing material 12 via a liquid crystal layer 11 made of, for example, a chiral nematic liquid crystal twisted at an angle of 200 to 270 °. Further, both transparent substrates 9,
A large number of spacers 44 are provided between the spacers 10 in order to keep the thickness of the liquid crystal layer 11 constant.

In the liquid crystal display device 21 in which the semi-transmissive film 42 is disposed as described above, when used as a reflection type (reflection mode), irradiation light by external illumination such as sunlight or a fluorescent lamp is used. Passes through the polarizing plate 36, the phase difference plate 35, and the liquid crystal panel sequentially, but the light incident inside the liquid crystal panel passes through the color filter 17, reaches the semi-transmissive film 42, and Then, the light passes through the liquid crystal panel, passes through the phase difference plate 35 and the polarizing plate 36, and is emitted.

On the other hand, when the liquid crystal display device 21 is set to the transmission mode, the irradiation light of the backlight 39 passes through the polarizing plate 38, the retardation plate 37 and the transparent substrate 10 of the liquid crystal panel in order, and becomes semi-transmissive. After passing through the film 42, the color filter 1
7 and then through the liquid crystal panel,
5 and the polarizing plate 36 to emit light.

Further, by forming the semi-transmissive film 42 on the transparent substrate 10, in the reflection mode, by increasing the reflectivity, a display with brighter brightness is obtained, and in the transmission mode, a high contrast is obtained. The reflection mode and the transmission mode can be enhanced to the extent that both functions of the reflection mode and the transmission mode can be satisfied.The panel used in the reflection mode can be used in the transmission mode under the same conditions. In each case, stable and vivid color display was achieved.

The semi-transmissive film 4 is formed on the inner surface of the transparent substrate 10.
2, the transparent substrate 1 is used even in the reflection mode.
0, so that the phenomenon that the display looks double due to the transparent substrate 10 does not occur. Further, since the incident light and the reflected light pass through the same pixel, a decrease in brightness and color purity is prevented.

The semi-transmissive film 42 is made of a metal thin film such as aluminum, chromium, SUS, or Ag. However, as the film thickness increases, the light transmittance decreases and the light reflectivity increases. The thickness of such a metal thin film has a different light absorption coefficient depending on the type of metal, and is also determined by which of the applications, the reflection mode and the transmission mode, requires improved performance. , Usually 50-500 °, preferably 100-400 °
It is good to Thereby, characteristics as a transflective liquid crystal display device having a reflectivity of 30 to 70% and a transmittance of 5 to 50% can be obtained.

For example, when the semi-transmissive film 42 is formed of an aluminum metal thin film having a thickness of 250.degree.
5% and the transmittance is 15%.

In the case of the liquid crystal display device 21 having the above structure, when the semi-transmissive film 42 is specular, a light scattering plate between the transparent substrate 9 of the liquid crystal panel and the retardation plate 35 is further provided. A body may be formed. For example, IDS (Internal Diffusin) manufactured by Dai Nippon Printing Co., Ltd.
g Sheet), which contains beads and the like in the resin. In addition, light scattering irregularities may be provided on the surface of the flat plate.

By providing such a light scattering film between the liquid crystal panel and the retardation plate 35, when used in the reflection mode, the reflected light reflected by the semi-transmissive film 42 is positively reflected by the light scattering film. The light is also scattered in directions other than the reflection direction, thereby increasing the viewing angle of the image display and widening the recognition area of the image display.

It should be noted that the present invention is not limited to the above embodiment, and various changes and improvements may be made without departing from the scope of the present invention. For example, in the above-described embodiment, the description has been made with the STN type simple matrix type color liquid crystal display device. However, in addition, a bistable type simple matrix type color and monochrome liquid crystal display device, and a monochrome type STN type simple matrix device are described. The same operation and effect can be obtained even in the liquid crystal display device of the above or the TN type simple matrix type liquid crystal display device.

Although the portable terminal is exemplified as the device provided with the liquid crystal display device of the present invention, the present invention can be applied to various devices using the liquid crystal display device as a display device. For example, it may be used as a display board of various display devices such as a sewing machine, a stereo, a musical instrument, a video, an ATM, a copier and a facsimile, a station, a restaurant, and a display panel in a factory.

[0062]

As described above, a dot matrix display section and an icon display section are formed via a nematic liquid crystal layer, and a conductive reflective layer or a semi-transmissive layer is formed on one of the substrates, and a dot is formed thereon. One stripe-shaped transparent electrode group corresponding to the matrix display portion, a common electrode corresponding to the icon display portion is formed, and the other stripe-shaped transparent electrode group corresponding to the dot matrix display portion on the other substrate. By forming a data display electrode corresponding to the icon display section and a dummy pattern energized with the common electrode, white spots are eliminated in the case of normally black display, and in the case of normally white display. As a result, it was possible to provide a high-performance reflective or transflective liquid crystal display device.

In the present invention, by providing the dummy pattern as described above, the cell gap becomes substantially equal over substantially the entire surface of the icon display portion, and the icon gap can be reduced when no voltage is applied as in the prior art. The phenomenon that the background is whitened no longer occurs.

Further, according to the present invention, by mounting the liquid crystal display device of the present invention on a portable terminal or a display device, the performance and quality thereof can be significantly improved.

[Brief description of the drawings]

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

FIG. 2 is a schematic sectional view of the liquid crystal display device of the present invention.

FIG. 3 is a sectional view of a main part of the liquid crystal display device of the present invention.

FIG. 4 is a schematic plan view of a conventional liquid crystal display device.

FIG. 5 is a sectional view of a conventional color liquid crystal display device.

FIG. 6 is a front view of the mobile phone according to the present invention.

FIG. 7 is a front view of the portable terminal according to the present invention.

FIG. 8 is a schematic sectional view of a transflective liquid crystal display device of the present invention.

[Explanation of symbols]

1, 21: liquid crystal display device, 2: color liquid crystal display device,
3, 23: icon display section, 4, 22: dot matrix display section, 9, 10: transparent substrate, 11: liquid crystal layer, 13,
26: common electrode, 14: signal electrode for dot matrix display, 16: reflective layer, 17: color filter layer, 1
8, 24: data electrode for icon display, 19: scanning electrode for dot matrix display, 25: dummy pattern,
28: mobile phone, 33: mobile terminal

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H092 GA05 GA13 GA15 GA21 GA26 GA28 GA33 HA03 HA05 NA01 NA04 PA06 PA08 PA09 QA07 QA10 5C006 AA22 AC01 AC02 AF36 AF78 BB12 EC08 EC13 FA22 5C080 AA10 BB05 CC03 DD05 EE28 EE32 JJ08 FF08 FF08 KK05 KK07 KK19 5C094 AA08 BA43 CA19 DA15 EA04 EA05 EA07 EB02 ED02 HA10

Claims (2)

[Claims] An image display device comprising: a first substrate and a second substrate disposed via a nematic liquid crystal layer to form a dot matrix display portion and an icon display portion; and a conductive reflective layer or semi-transmissive layer on one substrate. On which one stripe-shaped transparent electrode group corresponding to the dot matrix display portion and a common electrode corresponding to the icon display portion are formed, and on one of the stripe-shaped transparent electrode group and the common electrode, The alignment film is covered, and the other stripe-shaped transparent electrode group is formed on the other substrate so as to be orthogonal to the one stripe-shaped transparent electrode group in correspondence with the dot matrix display section, and in correspondence with the icon display section. A data display electrode and a dummy pattern energized with the common electrode are formed, and an alignment film is coated on the other stripe-shaped transparent electrode group, the data display electrode, and the dummy pattern. The liquid crystal display device comprising Te. 2. A portable terminal or display device provided with the liquid crystal display device according to claim 1.