KR100298391B1 - liquid crystal display device, its fabricating method and liquid crystal composition for display device - Google Patents

Abstract

The present invention is to provide a liquid crystal display device, a manufacturing method thereof, and a liquid crystal mixed material for manufacturing the liquid crystal display device by simplifying the manufacturing process by manufacturing a liquid crystal display device using a spraying method or a screen printing process.

The liquid crystal display device according to the present invention comprises a first electrode having a plurality of electrode lines arranged in parallel on a first substrate, and a dye mixture formed by spraying or screen printing so as to correspond to pixels on each electrode line of the first electrode. And a second electrode having a liquid crystal layer and a plurality of electrode lines arranged parallel to the second substrate, and having a second electrode formed on the dye mixed liquid crystal layer to be aligned with the dye mixed liquid crystal layer.

Description

Liquid crystal display device, its manufacturing method and liquid crystal material for display TECHNICAL FIELD

The present invention relates to a liquid crystal display device, a manufacturing method thereof, and a liquid crystal material for manufacturing a liquid crystal display. Specifically, a liquid crystal material, SiO ₂ nanoparticles (nano particles), an ultraviolet curable resin, a dye, a surfactant, and the like are used. The present invention relates to a liquid crystal material for a liquid crystal display, a reflective or light transmissive liquid crystal display device having a liquid crystal layer formed by printing or coating using the same, and a method of manufacturing the same.

Recently, liquid crystal display technology has been remarkably developed, and is now being used in many fields such as notebook computers.

In particular, TFT LCDs using the active matrix method have a performance comparable to that of conventional CRTs or CDTs in terms of picture quality, and are expected to replace existing display devices at a high speed in the future.

In the conventional TFT LCD manufacturing process, a thin film transistor is formed on a glass substrate and then a liquid crystal material is injected between two glass substrates. In this case, the injection of the liquid crystal material is not only to inject, but also to adjust the orientation, thickness, etc., and also requires a deflection plate and a color filter orthogonal to the top and bottom, and enhances brightness at the wide viewing angle layer and the rear to secure the viewing angle limitation. A backlight is needed to achieve this, and a lens is required to focus and uniformize it.

Therefore, the liquid crystal display device using the conventional TFT LCD has a complicated manufacturing process and a complicated structure, which not only increases the cost of the product but also increases the size of the product, which requires a lot of investment cost and a narrow viewing angle. The city has a problem that it is difficult to use for a long time because the power consumption is severe.

As to solve the conventional problems as described above, such as the M.Krauser the "MOI. Cryst Liq. Cryst. 1992. Vol. 223, P219", the liquid crystal and in a paper published in the German Daeque's Nano SiO ₂ particle The display device is made of a liquid crystal material mixed with Aerosil and UV Curable Resin at a predetermined ratio, and when the voltage is applied to the liquid crystal, it becomes transparent and becomes opaque when the voltage is released. A liquid crystal display device using the same is disclosed.

In the display manufacturing method disclosed in the paper, first, FNLC (Filled Nematic Liquid Crystal) is mixed by mixing liquid crystal material, aerosol and ultraviolet curable resin at 70-95% by weight, 5-25% by weight, and 1-10% by weight, respectively. After making, the FNLC is sandwiched between glass substrates coated with ITO electrodes, pressed, and cured by irradiation with ultraviolet rays, thereby fixing two glass substrates formed by coating electrodes.

When the voltage is applied to the ITO electrode of the liquid crystal display device manufactured and manufactured as described above, the FNLC becomes a transparent state and when the voltage is turned off, the display is implemented by using the phenomenon of returning to the opaque original state. The display device used has the advantage of being simpler in structure and manufacturing process than the above-described TFT LCD, but it is not simply applied to a color display because it is displayed only in black and white, and still has not solved the complexity of the manufacturing process.

Accordingly, an object of the present invention is to provide a liquid crystal display device and a method for manufacturing the same by simplifying the manufacturing process by manufacturing a liquid crystal display device using a printing or spraying process.

Another object of the present invention is to provide a liquid crystal display device and a method for manufacturing the same, which do not require a backlight, a polarizing plate, and a color filter by forming a liquid crystal layer from a dye-mixed liquid crystal material mixed with a dye and a liquid crystal material.

Yet another object of the present invention is to provide a mixed liquid crystal material for the manufacture of a liquid crystal display device suitable for screen printing.

1 is a view schematically showing a liquid crystal display device of the present invention;

2 (a) to 2 (d) are diagrams schematically showing states at respective steps of the liquid crystal display device of the present invention;

3 is a graph showing light transmittance against voltage variation of the liquid crystal display device of the present invention.

Explanation of symbols for main parts of the drawings

10: upper substrate 11, 14: electrode line

12: lower electrode 13-1, 13-2, 13-3: RYB mixed liquid crystal layer

15: upper electrode 16: upper substrate

The liquid crystal display device of the present invention for achieving the above object is screen printing or having a first electrode having a plurality of electrode lines arranged in parallel on the first substrate, the pixel corresponding to each electrode line of the first electrode or And a second electrode having a dye-mixed liquid crystal layer formed by spraying and a plurality of electrode lines arranged in parallel with the second substrate, and arranged on the dye-mixed liquid crystal layer to be aligned with the dye-mixed liquid crystal layer. .

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, the method comprising: forming a plurality of electrode lines in parallel on a first substrate to form a first electrode, and dyeing a pixel to correspond to each electrode line of the first electrode. Forming a dye-mixed liquid crystal layer by screen printing or spraying each color layer sequentially using a liquid crystal mixed material, and forming a second electrode by arranging a plurality of electrode lines in parallel on the second substrate And aligning and fixing the two electrodes on the mixed liquid crystal layer.

In addition, the dye-mixed liquid crystal material for display of another embodiment of the present invention is 60-95% by weight of the liquid crystal material, 5-25% by weight of aerosol, 1-10% by weight of UV curable resin, 1-5% by weight of surfactant and dye 3 It is characterized by consisting of -10%.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 schematically shows a liquid crystal display device of the present invention.

The liquid crystal display device of the present invention has a lower electrode having a lower substrate 10 formed of a conventional glass and a plurality of parallel electrode lines 11 formed of transparent ITO on the lower substrate 10 so as to correspond to pixels. 12), RYB mixed liquid crystal layers 13-1, 13-2, and 13-3 formed by spatially separating an RYB color layer with respect to one pixel on the lower electrode 12, and the RYB mixed liquid crystal layer. The upper substrate 16 includes a plurality of parallel electrode lines 14 aligned on the mixed liquid crystal layers 13-1, 13-2, and 13-3 and positioned to intersect with the electrode lines 11 of the lower electrodes. Is composed of an upper electrode 15 formed of transparent ITO.

In the present embodiment, the case of the transmissive type through which light is transmitted from the lower electrode on the lower substrate is shown. In the reflective type, the lower electrode is formed of opaque aluminum or gold.

The structure of the electrode is a simple matrix, and the lower electrode 12 and the upper electrode 15 are a collection of electrode lines 11 and 14 arranged in a straight line, and the number of lines is a type of display device. In the case of a general TV, the array of pixels is 640 × 480, but in reality, each pixel has three colors of RYB, so the total number of lines is 640 × 1440 or 1920 × 480.

Which one is the upper substrate and which one is the lower substrate is arbitrarily selected according to the design. In this embodiment, the lower substrate is 1920 electrode lines b1-b1920, and the upper substrate is 480 electrode lines a1-a480. For example, with).

The upper electrode line 14 and the lower electrode line 11 are arranged to be orthogonal to each other, and a portion where the upper electrode line 14 and the lower electrode line 11 are orthogonal becomes one of the RYBs of each pixel.

The RYB mixed liquid crystal liquid is 70-95% by weight of conventional liquid crystal material, 5-25% by weight of aerosol, 1-10% by weight of UV curable resin, 1-5% by weight of surfactant, and dye 3- by weight. It consists of 10%.

The dye of the mixed liquid crystal used in the present invention serves to give a color in the scattering mode, and has a red, yellow, blue or red, green, blue or black color depending on the type of the dye.

The surfactant makes the mixing of the aerosol and the liquid crystal material well and improves the printing characteristics.

When a voltage is applied to the dye-mixed liquid crystal layer corresponding to the electrode line intersected by applying a voltage to an arbitrary electrode line between the upper electrode 15 and the lower electrode 12 of the liquid crystal display device of the present invention configured as described above, the dye Since the mixed liquid crystal layer becomes transparent and the dye mixed liquid crystal layer to which no voltage is applied becomes a scattering mode to display colors, a predetermined display is realized by transmitting white light behind the lower substrate.

That is, the driving method of the display device of the present invention uses a sequential scanning method that is frequently used in a simple matrix structure.

When a constant voltage signal is applied to b1-b1920, the electrode line 11 of the lower electrode 12, and power is switched to a1-a480, the electrode line 14 of the upper substrate 16, for each dot of each line that crosses. The process of being transparent and coming out of color is repeated.

In the liquid crystal display device of the present invention, when the transmittance of light with respect to the voltage of the liquid crystal layer was measured, the characteristic graph shown in FIG. 3 was obtained.

As can be seen from the characteristic graph of FIG. 3, light transmittance of about 27% is represented at about 27V, and when the power is turned off, the light is returned to the opaque state and the color according to the pigment.

At this time, since the lower electrode 11 is transparent, when the white light is applied from the back, the color according to the dye comes out when no voltage is applied, and when the voltage is applied, the dye mixed liquid crystal layer becomes transparent and the white light of the back passes through as it is and appears white.

In the embodiment of the present invention, a yellow dye is used, but a green dye may be used instead of the yellow dye.

Unlike the transmissive type, when applied to the reflective type, it is just the front view, so when the voltage is applied and the liquid crystal becomes transparent, the light is reflected out. Otherwise, the color according to the pigment is emitted. As described above, an opaque aluminum or gold thin film electrode is used instead of the transparent ITO.

Hereinafter, the manufacturing method of the liquid crystal display device of this invention is demonstrated.

2 (a) to 2 (d) schematically illustrate the manufacturing process of the liquid crystal display device of the present invention. First, a method of sputtering transparent ITO on the glass lower substrate 10 as shown in FIG. After forming a thickness of about 100 ~ 300A by using a conventional photoetching process to form a plurality of lower electrode lines 11 arranged in parallel to form a lower electrode 12.

In this case, the number of electrode lines is different depending on the type of TV to be displayed as described above. In this embodiment, the total number of lines of 1920 × 480 is adopted to set the electrode lines of the lower electrodes to 1920 lines.

According to the electrode line 11 formed on the lower substrate 10 formed as described above, the red liquid crystal layer 13-1 is screen-printed, for example, and then cured by irradiating ultraviolet rays with a gap corresponding to the pixel.

At this time, the irradiation time of ultraviolet light varies depending on the intensity of ultraviolet light, but it usually takes several seconds to several tens of seconds.

Then, after screen printing the yellow liquid crystal layer 13-2 as shown in Fig. 2 (b) it is irradiated with ultraviolet rays to cure.

Subsequently, after screen printing the blue liquid crystal layer 13-3 as shown in FIG.

At this time, the thickness of the printed liquid crystal material is 5-25㎛. If the thickness is too thin, the contrast is bad, and if the thickness is too thick, a large amount of voltage is required at the time of driving.

Then, the upper electrode 15 is formed on the glass upper substrate 16 by forming a plurality of parallel electrode lines 14 in the same manner as in manufacturing the lower electrode 10.

The number of electrode lines at this time is 480, for example.

The electrode line 14 of the upper electrode 15 thus manufactured is aligned with the RYB mixed liquid crystal layers 13-1, 13-2, and 13-2 as shown in phantom in FIG. 2 (d). The substrate 16 is pasted.

At this time, the UV curable resin is widely applied to the upper substrate 16, and then the lower substrate 10 and the upper substrate 16 are compressed and irradiated with ultraviolet rays to cure.

Alternatively, the liquid crystal mixture material, which is not mixed with pigment, may be coated on the upper substrate 16 and then adhered to the lower substrate 10 to irradiate and cure ultraviolet rays.

In addition, when compressing while applying heat to increase the uniformity of the film thickness, softening occurs and is easily compressed.

The temperature at this time is between 40-100 degrees.

In the manufacturing method of the embodiment, screen printing is used, but in addition to screen printing, a different color (Red, Yellow or Green, Blue, Black) solution is sequentially formed on the substrate by using an injector such as a syringe. Spraying can be used.

As described above, the present invention can simplify the manufacturing process by using a screen printing process or a spraying method in the manufacture of the liquid crystal display device, and implements a display by using a transmission and scattering mode, so that the conventional liquid crystal display device No polarizing plate is needed, and the dye itself is colored by mixing with the liquid crystal material, so the color filter does not need to be installed separately, and the liquid crystal material mixed by dye color is printed separately and printed as an electrode of a simple matrix structure. It has excellent effects such as driving.

Claims (11)

A first electrode having a plurality of electrode lines arranged in parallel on the first substrate, A dye-mixed liquid crystal layer formed by screen printing or spraying to correspond to pixels on each electrode line of the first electrode; And a second electrode having a plurality of electrode lines arranged in parallel with a second substrate, and having a second electrode formed on the dye-mixed liquid crystal layer to be aligned with the dye-mixed liquid crystal layer. The method of claim 1, Each electrode line of the first electrode is formed of transparent ITO. The method of claim 1, Wherein each electrode line of the first electrode is formed of opaque aluminum or gold. The method of claim 1, And the first electrode and the second electrode are formed to cross each electrode line. Forming a first electrode layer by forming a plurality of electrode lines parallel to the first substrate, Forming dye-mixed liquid crystal layers sequentially by screen printing or spraying each color layer by using a dye-mixed liquid crystal material to correspond to pixels on each electrode line of the first electrode; And arranging a plurality of electrode lines parallel to a second substrate to form a second electrode, and then aligning and fixing the plurality of electrode lines on the dye-mixed liquid crystal layer. The method of claim 5, The dye-mixed liquid crystal material of the liquid crystal display device, characterized in that consisting of 60 to 95% of the liquid crystal material, 5 to 25% of the aerosol, 1 to 10% of the ultraviolet curable resin, 1 to 5% of the surfactant and 3 to 10% of the dye Manufacturing method. The method of claim 5, The dye-mixed liquid crystal material of the printing thickness is a manufacturing method of the liquid crystal display device, characterized in that 5-25㎛. The method of claim 5, In the fixing of the second electrode, the UV curable resin is lightly coated on the second electrode and the dye-mixed liquid crystal layer, and then both sides are compressed and cured by UV irradiation to fix the liquid crystal display device. The method of claim 5, The fixing of the second electrode may include coating a dye-mixed liquid crystal material in which the dye is not mixed on the second substrate, and then compressing the first substrate and then curing the ultraviolet rays to fix the second substrate. . The method of claim 1, The temperature at the time of the pressing is a manufacturing method of the liquid crystal display device, characterized in that 40 ~ 100 ℃. The method of claim 1, The dye mixed liquid crystal layer is a liquid crystal display device, characterized in that the RYB mixed liquid crystal layer.