JPH08234162A - Liquid crystal display device with integrated touch panel - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object of the present invention to provide an extremely thin and light touch panel integrated liquid crystal display device that does not cause color unevenness due to pressing force at the time of input. [Structure] A display-side substrate of a liquid crystal display panel and a back-side substrate of a touch panel are configured by a single common substrate, and a ferroelectric polymer liquid crystal is included as a liquid crystal material sealed in the liquid crystal display panel. Use liquid crystal material.

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 used as a display for electronic equipment and the like, and more particularly to a liquid crystal display device having an input function by a touch panel.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device having an input function using a touch panel is first shown in FIG.
Touch panel display side substrate 21 made of a plastic film or the like and touch panel back side substrate 2 made of glass or the like
2, a touch panel electrode pattern 27 is formed, and a dot spacer 32 made of an ultraviolet curable resin or the like is formed on the surface of the touch panel back side substrate 22 on which the touch panel electrode pattern 27 is formed. The side substrate 21 and the touch panel back side substrate 22 made of glass or the like are attached to each other via the double-sided adhesive tape 31 so that the touch panel electrode patterns 27 face each other to form the touch panel 36.

After that, the liquid crystal display panel display surface side substrate 23
And a liquid crystal display panel back side substrate 24, a liquid crystal display panel electrode pattern 28 is formed, and the liquid crystal display panel display side substrate 23 and the liquid crystal display panel back side substrate 24 are opposed to each other by the liquid crystal display panel electrode pattern 28. As described above, the low-molecular liquid crystal material 30 is sealed by adhering it through the sealing material 29, and the polarizing plate 25 is adhered to the surface of the liquid crystal display panel display surface side substrate 23 opposite to the liquid crystal display panel electrode pattern 28. A polarizing plate-integrated reflection plate 26 is attached to the opposite surface of the liquid crystal display panel electrode pattern 28 of the side substrate 24 to produce a liquid crystal display panel 37, and the touch panel 36 and the liquid crystal display panel 37 produced as described above are provided between the touch panel 36 and the liquid crystal display panel 37. Air layer 3
It has been common to provide 8 and stack them.

Further, as a liquid crystal material used for a liquid crystal display device having an input function by a touch panel, Japanese Patent Laid-Open No. Sho 63-63 is available.
-72784 discloses the use of a ferroelectric polymer liquid crystal material.

[0005]

As described above, in the conventional liquid crystal display device having the input function by the touch panel, the air layer 38 is provided between the touch panel 36 and the liquid crystal display panel 37, and the liquid crystal display panel is provided. It is laminated so that the pressing force is not applied to 37, but its air layer 3
The refractive index of light at 8 is the liquid crystal material 30 and the electrode substrates 21, 2
Since it is significantly lower than the refractive index of light at 2, 23, and 24, there is a problem that light is attenuated and the contrast is significantly reduced.

In order to solve such a problem, Japanese Patent Laid-Open No. 61-131314 discloses a method as shown in FIG.
There is disclosed a liquid crystal display device in which an adhesive layer 33 is provided and laminated between a touch panel 36 and a liquid crystal display panel 37. This is a touch panel 36 and a liquid crystal display panel 37.
Between the liquid crystal material 30 and the electrode substrate 21,
By providing the adhesive layer 33 made of a material having a light refractive index of 22, 23, and 24 close to that of the light, it is possible to prevent deterioration of contrast and the like.

However, in this method, when an input is made on the touch panel 36 with a pen or the like, a pressing force is also applied to the liquid crystal display panel 37 laminated below the touch panel 36. TN (Twisted Nematic) using low molecular liquid crystal material
Mode and STN (super twisted nematic)
There is a problem in that color unevenness occurs in the liquid crystal display panel 37 which is a display mode such as a mode.

Further, as a method for reducing the thickness of a liquid crystal display device having an input function by a touch panel, Japanese Patent Laid-Open No. Hei 4 (1998)
As shown in FIG. 5, Japanese Patent Publication No. 243412 discloses a liquid crystal display device in which a display surface side substrate of a liquid crystal display panel 36 and a back surface side substrate of a touch panel 37 are configured by a common single substrate 34. . This is to reduce the thickness of the entire liquid crystal display device by forming the display surface side substrate of the liquid crystal display panel 37 and the back surface side substrate of the touch panel 36 by one common substrate 34.

However, in this method, when the touch panel 36 is input with a pen or the like, a pressing force is applied to the liquid crystal display panel 37 laminated on the lower side of the touch panel 36. Therefore, there is a problem in that color unevenness occurs in the liquid crystal display panel 37 which is a display mode such as a TN mode or an STN mode using a low molecular weight liquid crystal material.

On the other hand, as a liquid crystal material used for a liquid crystal display device having a touch panel input function, a ferroelectric polymer liquid crystal material 35 as shown in FIG. Liquid crystal display panel 37 used
In addition, a liquid crystal display device in which a touch panel 36 is laminated is disclosed in JP-A-5-264953.

However, in this configuration, since the touch panel 36 is attached to the liquid crystal display panel 37, when the display surface side substrate 21 and the back surface side substrate 22 of the touch panel 36 are attached, and when the liquid crystal display panel 37 is attached. Since a highly accurate alignment is required at the time of bonding with the touch panel 36, there is a problem in that a defect due to a positional deviation is likely to occur at each bonding.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and does not cause color unevenness due to the pressing force at the time of input, and is a very thin and light touch panel integrated liquid crystal display. The purpose is to provide a device.

[0013]

A touch panel integrated type liquid crystal display device of the present invention is a touch panel integrated type liquid crystal display device integrally comprising a touch panel and a liquid crystal display panel, wherein the display surface side substrate of the liquid crystal display panel. And a backside substrate of the touch panel, which is formed of a common single substrate, and a liquid crystal material containing a ferroelectric polymer liquid crystal is used as a liquid crystal material sealed in the liquid crystal display panel. Therefore, the above-mentioned object is achieved.

A polarizing plate or a reflector integrated with polarizing plate may be used as the back surface side substrate of the liquid crystal display panel, and a polarizing plate may be used as the display surface side substrate of the touch panel.

[0015]

According to the present invention, the display-side substrate of the liquid crystal display panel and the back-side substrate of the touch panel are formed of a single common substrate, so that the number of substrates can be reduced by one. A very thin and light touch panel integrated liquid crystal display device can be realized.

Further, since there is no space between the touch panel and the liquid crystal display panel, it is possible to prevent the deterioration of contrast due to the attenuation of light.

Further, by using a polarizing plate or a polarizing plate integrated with a polarizing plate as the back side substrate of the liquid crystal display panel and using a polarizing plate as the display side substrate of the touch panel, a thinner and lighter touch panel integrated liquid crystal display device is obtained. Can be realized.

Furthermore, by using a liquid crystal material containing a ferroelectric polymer liquid crystal as a liquid crystal material sealed in the liquid crystal display panel, the orientation of the liquid crystal molecules is not disturbed even when a shock or pressure is applied from the touch panel. Therefore, even in a liquid crystal display device integrally provided with a touch panel, color unevenness does not occur due to the pressing force at the time of input.

Therefore, due to the impact resistance and pressure resistance of the liquid crystal material containing the ferroelectric polymer liquid crystal, the display surface side substrate of the liquid crystal display panel and the back surface side substrate of the touch panel are formed of a common single substrate. Even if the pressure applied at the time of input does not cause color unevenness, a very thin and light touch panel integrated liquid crystal display device can be realized.

Further, since the memory property of the ferroelectric liquid crystal material can be utilized, the power consumption can be reduced, and the display is not thin even after the voltage is turned off. A display device can be realized.

[0021]

EXAMPLES The present invention will be specifically described below based on examples.

(Embodiment 1) FIG. 1 is a schematic sectional view of a touch panel integrated type liquid crystal display device in this embodiment. In this embodiment, transparent electrodes made of ITO are respectively formed on one surface of two sheets of polyether sulfone (hereinafter abbreviated as PES) having a thickness of 0.1 mm, and one sheet is used as the display surface side substrate 1 of the touch panel 12. The other one was used as the back side substrate 3 of the liquid crystal display panel 13. In addition, the thickness P of 0.1 mm
Transparent electrodes made of ITO were respectively formed on both sides of the ES to form a double-sided substrate 2 for the display side substrate of the liquid crystal display panel 13 and the back side substrate of the touch panel 12.

After that, a touch panel electrode pattern 6 was formed on the display surface side substrate 1 of the touch panel 12, and a liquid crystal display panel electrode pattern 7 was formed on the back surface side substrate 3 of the liquid crystal display panel 13. Further, on the substrate 2 which is also used as the display side substrate of the liquid crystal display panel 13 and the back side substrate of the touch panel 12, the liquid crystal display panel electrode pattern 7 is formed on one side and the touch panel electrode pattern 6 is formed on the other side. did.

As the sealing material 8, an ultraviolet curable resin having flexibility even after curing was used. This sealing material 8
The liquid crystal display panel 13 of the substrate 2 which is also used as the display side substrate of the liquid crystal display panel 13 and the back side substrate of the touch panel 12.
It was applied using a dispenser so as to be located on the outer peripheral portion of the side electrode pattern 7.

After that, the ferroelectric polymer liquid crystal material 9 dissolved in a solvent to improve the fluidity is applied on the electrode pattern 7 of the back side substrate 3 of the liquid crystal display panel so as to correspond to the inside of the sealing material 8. After coating by the microgravure method, the solvent was volatilized.

Then, a substrate 2 serving as both a display side substrate of the liquid crystal display panel 13 and a back side substrate of the touch panel 12,
The rear substrate 3 of the liquid crystal display panel 13 is aligned with the liquid crystal display panel electrode patterns 7 so as to face each other so that the ferroelectric polymer liquid crystal material 9 can be formed inside the seal material 8. The pieces were attached and irradiated with ultraviolet rays to cure the sealing material 8. Furthermore, the liquid crystal display panel 13 was manufactured by performing the alignment treatment by the mechanical alignment method.

Next, dot spacers 11 made of an ultraviolet curable resin are formed by screen printing on the surface of the liquid crystal display panel 13 on which the touch panel electrode pattern 6 is formed, and the display surface side substrate 1 of the touch panel 12 is formed. So that it is located on the outer periphery of the electrode pattern 6 for the touch panel,
After forming the double-sided adhesive tape 10, the liquid crystal display panel 13
The electrode pattern 6 for a touch panel formed on the dual-purpose substrate 2 and the display-side substrate 6 of the touch panel 12 were attached so as to face each other.

Further, a polarizing plate 4 is attached to the display-side substrate 1 of the touch panel 12, and a reflector-integrated polarizing plate 5 is attached to the back-side substrate 3 of the liquid crystal display panel 13, so that the touch panel-integrated liquid crystal display in this embodiment is obtained. The device was made.

(Embodiment 2) FIG. 2 is a schematic sectional view of a liquid crystal display device integrated with a touch panel according to this embodiment. In this example, as shown in FIG. 2, a polarizing plate 4 was used as the display surface side substrate 1 of the touch panel 12, and a reflector integrated polarizing plate 5 was used as the rear surface side substrate 3 of the liquid crystal display panel 13. . Other steps were performed in exactly the same manner as in Example 1 to fabricate the touch panel integrated liquid crystal display device in this example.

The touch panel integrated type liquid crystal display device realized by the present invention may be a reflection type liquid crystal display device having a reflection plate or a transmission type liquid crystal display device having a light source. In order to take advantage of the features of thinness and lightness, a reflective liquid crystal display device is preferable.

The ferroelectric polymer liquid crystal material used in the present invention is, for example, one or two or more ferroelectric polymer liquid crystal materials, or one or two or more ferroelectric polymer liquid crystal materials and one or two. Ferroelectric polymer liquid crystal material composed of one or more ferroelectric low molecular liquid crystal materials, ferroelectric composed of one or more kinds of ferroelectric low molecular liquid crystal materials and one or more kinds of other polymer liquid crystal materials Liquid crystalline polymer materials can be used.

That is, the ferroelectric polymer liquid crystal material used in the present invention is not limited to the ferroelectric polymer liquid crystal material in which the polymer molecule itself exhibits ferroelectric liquid crystal characteristics, but the polymer showing all ferroelectric properties. A liquid crystal material can be used.

Examples of the ferroelectric polymer liquid crystal material include acrylate main chain liquid crystal polymer, methacrylate main chain liquid crystal polymer, chloroacrylate main chain liquid crystal polymer, oxirane main chain liquid crystal polymer, and siloxane main chain liquid crystal. Polymers, siloxane-olefin main chain type liquid crystal polymers, ester main chain type liquid crystal polymers and the like can be mentioned, and side chain type ferroelectric polymer liquid crystal materials having a chiral smectic C phase are preferable, but the present invention is these materials. It is not limited to.

If desired, the ferroelectric polymer liquid crystal material may contain an adhesive, a viscosity reducing agent, a non-liquid crystal chiral compound, a dye or the like.

Further, in the plastic film, plastic sheet, polarizing plate and polarizing plate integrated with a reflector used as the electrode substrate in the present invention, a hard coat layer, a gas barrier layer,
An undercoat layer or the like may be formed.

Further, the electrode material used in the present invention is not particularly limited, and the electrode material for the touch panel and the electrode material for the liquid crystal display panel may be the same or different.

[0037]

According to the present invention, the display-side substrate of the liquid crystal display panel and the back-side substrate of the touch panel are formed of a single common substrate, and a ferroelectric material is used as the liquid crystal material sealed in the liquid crystal display panel. It is characterized by using a liquid crystal material containing a liquid crystalline polymer. With such a structure, the number of substrates can be reduced by one, and a very thin and light touch panel integrated liquid crystal display device is realized. it can.

Further, since there is no space between the touch panel and the liquid crystal display panel, it is possible to prevent the deterioration of contrast due to the attenuation of light.

Further, since the ferroelectric polymer liquid crystal material is used as the liquid crystal material sealed in the liquid crystal display panel, the orientation of the molecules is not disturbed even when a shock or pressure is applied,
Even in a liquid crystal display device integrally equipped with a touch panel, color unevenness due to the pressing force at the time of input does not occur, so that the display side substrate of the liquid crystal display panel and the back side substrate of the touch panel are commonly used. Since it is possible to reduce the number of substrates by using one substrate, it is possible to realize a very thin and light touch panel integrated liquid crystal display device.

Further, it is possible to use a memory property of a ferroelectric liquid crystal material, reduce power consumption, and a very thin and light touch panel integrated liquid crystal display device in which the display does not disappear even after the voltage is turned off. Can be realized.

Furthermore, by using a polarizing plate or a polarizing plate integrated with a polarizing plate as the back side substrate of the liquid crystal display panel and using a polarizing plate as the display side substrate of the touch panel, respectively, a thinner and lighter touch panel integrated liquid crystal display. The device can be realized.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a touch panel integrated liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of a touch panel integrated liquid crystal display device according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view of a liquid crystal display device having a conventional touch panel.

FIG. 4 is a schematic cross-sectional view of a conventional touch panel integrated liquid crystal display device.

FIG. 5 is a schematic cross-sectional view of a conventional touch panel integrated type liquid crystal display device in which the display surface side substrate of the liquid crystal display panel and the back surface side substrate of the touch panel are configured by one common substrate.

FIG. 6 is a schematic sectional view of a conventional touch panel integrated liquid crystal display device using a ferroelectric polymer liquid crystal material as a liquid crystal material.

[Explanation of symbols]

1 touch panel display side substrate 2 liquid crystal display panel display side substrate and touch panel back side substrate 3 substrate 3 liquid crystal display panel back side substrate 4 polarizing plate 5 polarizing plate integrated reflector 6 touch panel electrode pattern 7 for liquid crystal display panel Electrode pattern 8 Seal material 9 Ferroelectric polymer liquid crystal material 10 Double-sided adhesive tape 11 Dot spacer 12 Touch panel 13 Liquid crystal display panel 21 Touch panel display side substrate 22 Touch panel back side substrate 23 Liquid crystal display panel display side substrate 24 Liquid crystal display panel back side Side substrate 25 Polarizing plate 26 Polarizing plate integrated reflector 27 Electrode pattern for touch panel 28 Electrode pattern for liquid crystal display panel 29 Seal material 30 Low-molecular liquid crystal material 31 Double-sided adhesive tape 32 Dot spacer 33 Adhesive layer 34 Liquid crystal display panel display side substrate And Alternate substrates 35 strong with Chipaneru rear substrate dielectric polymeric liquid crystal material 36 touch 37 liquid crystal display panel 38 an air layer

Claims (2)

[Claims] 1. A touch panel integrated type liquid crystal display device integrally comprising a touch panel and a liquid crystal display panel, wherein a display side substrate of the liquid crystal display panel and a back side substrate of the touch panel are common. A liquid crystal display device integrated with a touch panel, comprising a substrate and using a liquid crystal material containing a ferroelectric polymer liquid crystal as a liquid crystal material sealed in the liquid crystal display panel. 2. The polarizing plate or a reflector integrated with polarizing plate is used as the back surface side substrate of the liquid crystal display panel, and the polarizing plate is used as the display surface side substrate of the touch panel. LCD device with integrated touch panel.