KR20060025501A - Display devices utilizing electrowetting and reflection - Google Patents

Abstract

There are many researches around the world that change the focus of liquid lenses or devices that move images by using electrowetting and the property that water and oil do not mix with each other.

The present invention is a device for expressing the image using a black oil, a transparent electrolyte solution and a color plate as a device for representing the color by pushing the black oil to water using electrowetting and reflecting the color of the red, blue, yellow color plate being. Black is represented by black oil, and white is represented by the three primary colors combined. Color brightness or saturation is expressed using the amount of black and color and the length of time that black and color intersect.

Black oil blocks light coming in contact with a hydrophobic surface coated on a transparent cover plate where light enters due to the force of water molecules to coalesce. When electricity is applied to the hydrophobic surface, the water wets the transparent cover plate surface and the black oil is pushed from side to side to the bottom. The conductive water, released by the electrolyte, is transparent so that the colored reflectors inside reflect the light from the outside. According to the present invention, the color plate and the screen surface are close and the color opacity is high, so that a clear color can be obtained and can be used to realize black, white, and other colors with little waste of external light.

Electrowetting, surface tension, liquid, oil, electrolyte, aqueous solution

Description

Display devices utilizing electrowetting and reflection

Figure 1 shows the color plate and black oil, the electrode.

Figure 2 shows the location of the three color plates.

Figure 3 is the appearance of black oil when using an external light source.

Figure 4 shows two color plates and black oil, the electrode.

5 shows the location of the two color plates.

Figure 6 is the appearance of black oil when using an external light source.

7 is a view when using the internal light source.

Figure 8 is a black oil is seen when using the internal light source.

<Explanation of symbols for main parts of drawing>

1: transparent negative electrode

2: transparent cover plate

3: transparent hydrophobic insulating film

4: transparent hydrophobic insulating film

5: black oil with high opacity

6: transparent aqueous solution with dissolved electrolyte                 

7: transparent negative electrode

8: colored reflector

9: hydrophilic colored reflector

10: Colored reflector support plate with hydrophilicity in contact with water

11: Colored reflector support plate with hydrophilicity in contact with water

12: (+) electrode

13: bottom plate (use transparent plate when using internal light source)

14: pixel walls

After discovering that Gabriel Reefmann could change the surface tension of a liquid by electricity in the 1870s, when electricity was applied to an insulated electrode from the 1980s, the liquid changed its surface tension and was able to wet the material in contact. Many people have studied liquid lenses that can be moved to liquid using electrowetting to create imaging devices or to refocus using immiscible liquids.

A device that reflects light and realizes an image is a method of reflecting colored light sources by placing numerous fine mirrors on a semiconductor, and reflecting the colored reflector through a polarizing filter such as a reflective liquid crystal display (LCD). How to control the amount of light that is spread, mercury is spread out using electrowetting broadly and narrowly collected to get an image by reflecting light, and how to spread and collect colored oil on the white reflector using electrowetting. Etc.

Make a thin image display device like LCD and PDP instead of a thick image display device using a cathode ray tube like a conventional TV or a computer monitor, and use an external light source instead of an internal light source. Electric wettability and water surface tension were used to develop the consuming device.

The present invention controls the area covering the color plate under the black oil by using the electrowetting, and controls the time to cover the color to express the color or black.

Water has surface tension to minimize surface area and avoid contact with hydrophobic surfaces. However, even if hydrophobic surfaces are supplied with electricity, the water gets wet. When the water is wet, the black oil, which had previously been in contact with the hydrophobic surface, leaves the place, and the transparent colored water reflects the light from outside. When the electricity is turned off, the water withdraws from the wide hydrophobic surface and the black oil occupies the original place, representing black.

Each color cell contains red, yellow, and blue, and the three primary colors are mixed to represent white and other colors, and the color and brightness of each color and black oil cover the color plate. Adjust                     

Color plates are colored coatings and hydrophilic or hydrophobic coatings where necessary, and the electrode inserted.

The left and right color plates 10 of FIG. 1 initially have a hydrophobic coating on the surface contacting the black oil 5, and the surface contacting the electrolyte solution 6 is hydrophilic.

The electrodes (1,7) are transparent and the middle colored plate is hydrophilic all around.

The transparent electrolyte aqueous solution 6 wets the hydrophobic surfaces 3 and 4 by electrowetting while flowing a current through the positive electrode 12 and the negative electrode 1 from the center of FIG. When the aqueous solution flows between (3) and the original black oil (5) is pushed to the left and right walls (14), the external light is reflected on the color plates (10, 11) to appear color.

When the current supply is interrupted, the water that was in contact with the wide hydrophobic surfaces (3, 4) will stick together and escape through the gaps themselves to minimize the surface area.

Therefore, it does not take electricity to maintain black in the image display (Fig. 3, Fig. 6), and when all black oil is pushed to the left and right walls, the color plate with high reflectivity reflects the vivid color (Fig. 3). 6, 8) and 8), when all three primary colors of the color are displayed, white color is displayed.

Figure 4 works on the same principle with a simpler structure than Figure 1; When a current is applied to the positive electrode and the negative electrode, the aqueous solution wets the hydrophobic surface from the center to the left and right walls, and black oil deviates (Fig. 6). When the current is turned off, the water has a tinge to minimize the contact area with the hydrophobic surface, so the black oil returns to its original position, preventing external light from reflecting off the color plate.

7 is a case of using an internal light source, a transparent hydrophilic plate is used on the bottom, and a positive electrode is also made of a transparent material so that the hydrophobic film 3 is coated only on a part which does not come into contact with water to supply light under the bottom plate like a transmissive LCD This allows you to display images in dark places.

When each unit with red, blue and yellow color plates displays one pixel, the electrical control of each unit uses the active matrix method as TFT LCD.

Compared to the prior art, the color plate reflecting the external light can show the color clearly with a thinner coating than the colored paint, and each cell can show one of black, red, blue, yellow and black The oil's opacity can be increased to achieve high contrast throughout the screen. Less loss of light since no polarization is used. The short distance that external light enters the front and penetrates to the color plate, so there is little loss of light and the viewing angle is large, and it uses less surface energy because it uses the surface tension of water when maintaining the black color occupied by the color plate. Instead of looking directly at the reflected light of the colored reflector, it can be projected onto the projection screen.

Claims (1)

Image display device using electrowetting and reflection to display an image by controlling the amount of light reflected by a colored reflector with black oil in still or moving image display

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