KR20070081736A - Display device - Google Patents

Abstract

A display device is provided to form a desirable image by using a field sequential light source and switching the light emitted from a backlight unit in order, with an optical shutter utilizing electrowetting. A display device is composed of a backlight unit(100) having a field sequential light source driven by a sequential partition method and an optical shutter(150) disposed at the front side of the backlight unit to switch the light emitted from the backlight unit by utilizing electrowetting. The optical shutter comprises first and second substrates(110) separated from each other in a predetermined gap and disposed with facing each other; plural first electrodes(112) formed on the inside of the first substrate; a dielectric layer(114) formed on the first substrate to cover the first electrodes; plural second electrodes(122) formed on the inside of the second substrate; and a transparent aqueous solution and an opaque organic solution filled among the second electrodes and the dielectric layer.

Description

Display device

1A and 1B are photographs of the droplets placed on the surface of the hydrophobic solid when the voltage is not applied and when the voltage is applied.

2A and 2B are cross-sectional views of an optical shutter apparatus using an electrowetting phenomenon, and show a case where a voltage is not applied and a case where a voltage is applied, respectively.

2C and 2D illustrate photographs in which oil is biased to one side of a pixel when voltage is applied after fabricating the pixels in the structure shown in FIG. 2A.

3 is a diagram schematically illustrating a display device according to an exemplary embodiment of the present invention.

4A and 4B are diagrams for describing an operation process of an optical shutter in a display device according to an exemplary embodiment of the present invention.

FIG. 5 illustrates a state in which light is transmitted by adjusting a magnitude of voltage applied between electrodes in the display device according to an exemplary embodiment of the present invention.

6 illustrates a modification of the partition wall that may be used in the display device according to the embodiment of the present invention.

7 is a diagram schematically illustrating a display device according to another embodiment of the present invention.

8A and 8B are diagrams for describing an operation process of an optical shutter in a display apparatus according to another exemplary embodiment of the present invention.

9 illustrates light of a predetermined color sequentially emitted from the field sequential light source.

10A to 10D sequentially illustrate a process of implementing an image by the display apparatus according to the present invention when light of a predetermined color is emitted from the backlight unit as shown in FIG. 9.

<Explanation of symbols for main parts of the drawings>

100,200 ... Backlight Unit 110,210 ... First Substrate

112,212. First electrode 114,214 ... Dielectric layer

115, 115 ', 215 ... bulkhead 120,220 ... second substrate

122,222 ... Second electrode 131,231 ... Aqueous solution

132,232 ... Organic solution 150,250 ... Light shutter

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly, to a novel display device comprising a backlight unit including a field sequential light source driven in a sequential division method and an optical shutter using an electrowetting phenomenon. It relates to a display device.

Conventionally, CRT monitors have been mainly used to display information of TVs and computers, but recently, as the screen size increases and becomes slimmer, a liquid crystal display (LCD) and a plasma display panel (PDP) are used. Flat panel displays such as field emission displays (FEDs) are used. Among such flat panel displays, power consumption is low, and a liquid crystal display (LCD) mainly used for a TV, a computer monitor, and the like is in the spotlight.

Conventional liquid crystal display (LCD) modulates the white light generated from the backlight unit by the liquid crystal layer, and then implements the image by passing the modulated white light through the red (R), green (G), and blue (B) filters. . However, in such a liquid crystal display device, it takes a lot of time and money to manufacture a color filter, and because each color filter passes only light of a predetermined color, only one third of the white light passing through the liquid crystal layer is used to lose light. This had a drawback of growing up.

Accordingly, in order to overcome such drawbacks, recently, a liquid crystal display device using a field sequential light emitting diode (LED) driven in a sequential manner as a backlight unit to implement an image with afterimage effect has been developed. In the liquid crystal display, red (R), green (G), and blue (B) light are sequentially emitted from the field sequential LEDs, and the light of the predetermined color passes through the liquid crystal layer to form Mars. In the liquid crystal display using the field sequential LED, a color filter is not required, so that an optical loss is reduced, and manufacturing time and cost of the liquid crystal display are reduced.

However, since the liquid crystal display using the field sequential LED as described above uses a polarizing plate as in the conventional liquid crystal display using the color filter, there is a limit to the effect of improving the luminance. In addition, when 60 frames are to be formed for one second, when one frame is composed of four R / G / B / Black subframes sequentially driven, each subframe should be driven at a speed of 240 Hz. Accordingly, a liquid crystal response speed of about 4 ms is required. In addition, when one frame is composed of six R / Black / G / Black / B / Black subframes sequentially driven, each subframe should be driven at a speed of 360 Hz. Accordingly, a liquid crystal response speed of about 3 ms is required. However, since the response speed of a general liquid crystal is about 25 ms, it is difficult to implement an image by using such a liquid crystal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a display device including a backlight unit including a field sequential light source driven in a sequential division method and an optical shutter using a fast response electrowetting phenomenon. There is a purpose.

In order to achieve the above object,

Display device according to an embodiment of the present invention,

A backlight unit including a field sequential light source driven in a sequential manner;

It is provided in front of the backlight unit to switch the light emitted from the backlight unit, and an optical shutter using an electrowetting phenomenon (optical shutter).

The optical shutter may include: first and second substrates spaced apart from each other at regular intervals to face each other; A plurality of first electrodes formed on an inner surface of the first substrate; A dielectric layer formed on the first substrate to cover the first electrodes; A plurality of second electrodes formed on an inner surface of the second substrate; And a transparent aqueous solution and an opaque organic solution filled between the second electrodes and the dielectric layer.

The optical shutter switches the light of a predetermined color emitted from the backlight unit for each pixel as the organic solution moves by applying a predetermined voltage between the first electrode and the second electrode.

Here, the gray scale of each pixel may be adjusted by adjusting the magnitude of the voltage applied between the first electrode and the second electrode.

Meanwhile, the second electrode may be formed in plural in correspondence with one pixel. In this case, the gray scale of each pixel may be adjusted by controlling the second electrodes to switch the voltage applied to each of the second electrodes.

A plurality of partition walls may be provided between the first substrate and the second substrate to partition the space between the first substrate and the second substrate to form pixels. Here, the lower portion of the barrier rib may be formed thinner than the upper portion of the barrier rib so that the organic solution may move and enter the lower portion of the barrier ribs.

It is preferable that the said 1st and 2nd board | substrate is a transparent substrate. The first electrodes may be formed to be parallel to each other, and the second electrodes may be formed to be parallel to each other in a direction crossing the first electrodes.

The first and second electrodes may be made of a transparent conductive material such as indium tin oxide (ITO), ZnO, or the like.

The dielectric layer preferably has a hydrophobic surface. In addition, the moving speed of the organic solution may be 0.1 cm / sec to 5 cm / sec.

The field sequential light source sequentially emits red (R) / green (G) / blue (B) / black (Black) light every frame, or red (R) / black / Green (G) / Black (Blue) / Blue (B) / Black (Black) light can be emitted sequentially.

The present invention uses an optical shutter using an electrowetting phenomenon to switch light of a predetermined color emitted from the backlight unit. Hereinafter, the electrowetting phenomenon will be described first, and then a display apparatus according to an embodiment of the present invention using the same will be described.

Electrowetting is a phenomenon that occurs because the wetting characteristics of a solid change when a voltage is applied. 1A and 1B are photographs of the droplets placed on the surface of the hydrophobic solid when the voltage is not applied and when the voltage is applied. Referring to FIG. 1A, when water droplets are placed on the hydrophobic solid surface, the hydrophilic water droplets exhibit poor contact with the hydrophobic solid surface and thus exhibit a high contact angle. However, when a voltage is applied to the hydrophobic solid, the surface of the solid becomes hydrophilic, as shown in FIG. 1B, and a wet phenomenon occurs.

 This phenomenon is represented by the following Lippman equation (Equation 1).

Referring to Equation 1, the contact angle (θ) of the liquid on the solid is not only the surface energy (γ _LV ) of the liquid and the gas, the surface energy (γ _SV ) of the solid and the gas, and the surface energy (γ _SL ) of the solid and the liquid. In addition, it can be seen that it is influenced by the applied voltage (V), the dielectric constant (ε _r ) of the solid and the thickness (d) of the solid.

2A and 2B are cross-sectional views of an optical shutter apparatus using an electrowetting phenomenon, and show a case where a voltage is not applied and a case where a voltage is applied, respectively. The optical shutter device is composed of an electrode, an dielectric layer, an oil, and water, and the oil includes a material that blocks light. In the optical shutter device having the above structure, when water and oil are placed in a mixture on the hydrophobic dielectric layer, the sum of the interfacial energy of the oil and the water and the interfacial energy of the oil and the dielectric layer is smaller than the sum of the interfacial energy of the water and the dielectric layer. As shown, the oil covers the entire dielectric layer and water is placed on the oil. Accordingly, light incident through the electrode is blocked by the oil. In the structure shown in FIG. 2A, when a voltage is applied between water and the dielectric layer, the dielectric layer having a hydrophobic surface is changed to hydrophilic, and as shown in FIG. 2B, the area in which water contacts the dielectric layer is increased. As a result, the light incident through the electrode passes through the water and is emitted upward. In the optical shutter device having the structure as described above, by adjusting the magnitude of the voltage applied between the water and the dielectric layer, the area of the water covering the dielectric layer can be adjusted, so that the gray level of the light emitted from the optical shutter device can be adjusted. do. 2C and 2D are photographs showing the oil (black portion) biased to one side of the pixel when a voltage is applied after fabricating the pixels in the structure shown in FIG. 2A. Referring to FIGS. 2C and 2D, the area of the oil covering the dielectric layer varies according to the applied voltage, and accordingly, the gray level of each pixel may be adjusted.

The optical shutter device using the electrowetting phenomenon described above can solve the problem that the response speed of the liquid crystal is slow in the conventional liquid crystal display (LCD) due to the fast response speed. Specifically, referring to Applied Physics letter 86, 151121, (2005), since the optical switch using the electrowetting phenomenon is known to realize a response speed of 10ms in a 1 × 1 mm size cell, a 100 × 100 μm size In the cell, a response speed of approximately 1 ms can be estimated. Therefore, the response speed of 3ms in the optical shutter using the electrowetting can be sufficiently implemented. In the case of using the electrowetting phenomenon without using the liquid crystal as the optical shutter, when the liquid crystal is used because the drive of the switch is a voltage driving method with almost no current flow and the light is not polarized when the optical shutter operates. Compared with the low current consumption, there is also an advantage that the viewing angle is not limited. These advantages are very important in a situation where high power consumption and low viewing angle in display devices are required.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

3 schematically shows a display device according to an embodiment of the present invention.

Referring to FIG. 3, the display apparatus according to the exemplary embodiment includes a backlight unit 100 and an optical shutter 150 for switching the light emitted from the backlight unit 100. In the present embodiment, a field sequential light source driven in a sequential manner is used as the backlight unit 100. Here, a light source diode (LED), an organic light emitting diode (OLED), or the like may be used as the field sequential light source driven in the sequential division method. The field sequential light source emits light of a predetermined color in a time division manner, and the display device according to the embodiment of the present invention implements an image with an afterimage effect using the field sequential light source. For example, the field sequential light source may be driven to sequentially emit four colors, i.e., red (R) / green (G) / blue (B) / black (Black) light per frame. Drives six colors per frame, i.e. red (R) / black (green) / green (G) / black (black) / blue (B) / black (Black) light sequentially Can be.

The optical shutter 150 is installed in front of the backlight unit 100 to switch light of a predetermined color emitted from the backlight unit 100. In the present embodiment, the optical shutter 150 switches light of a predetermined color that is sequentially emitted by using an electrowetting phenomenon as described above. The optical shutter 150 may include first and second substrates 110 and 120 spaced apart from each other at regular intervals, and a plurality of first electrodes 112 formed on an inner surface of the first substrate 110. A dielectric layer 114 formed on an inner surface of the first substrate 110 to cover the first electrode 112, a plurality of second electrodes 122 formed on an inner surface of the second substrate 120, and And a solution filled between the second electrodes 122 and the dielectric layer 114.

In general, a glass substrate or a plastic substrate may be used as the first and second substrates 110 and 120. Here, when both the first and second substrates 110 and 120 are used as plastic substrates, a flexible display can be implemented. The first and second electrodes 112 and 122 may be made of a transparent conductive inorganic material such as indium tin oxide (ITO) or ZnO. In addition, the first and second electrodes 112 and 122 may be transparent conductive inorganic composites or organic films. The first electrodes 112 may be formed in parallel with each other, for example, in a stripe shape. The second electrodes 122 may be formed to be parallel to each other in a direction crossing the first electrodes 112, for example, orthogonal to the second electrodes 122. In this case, pixels are formed in regions where the first and second electrodes 112 and 122 intersect with each other. In addition, the first and second electrodes 112 and 122 may be formed in various shapes. For example, each of the first electrodes 112 may be formed in a shape corresponding to a pixel, and the second electrodes 122 may be integrally formed to cover the bottom surface of the second substrate 120.

The dielectric layer 114 is preferably made of a transparent material, and the surface of the dielectric layer 114 preferably has a hydrophobic property. The dielectric layer 114 may be made of fluoropolymer, parylene, or the like as an organic material, and may be made of SiO ₂ (silicon dioxide), BST (Barium Strontium Titanate), or the like. In particular, when the dielectric layer 114 is made of SiO ₂ , BST, it is used after coating an organic material, for example, fluoropolymer, parylene, etc. to give sufficient hydrophobicity to the surface of the dielectric layer 114. In addition to having hydrophobicity, the dielectric layer 114 preferably has a higher dielectric constant as the thickness thereof is thinner according to the Lippman equation. When the dielectric layer 114 is made of an organic material such as fluoropolymer, parylene, etc., hydrophobicity is sufficient, but the breakdown voltage is low. In addition, when the dielectric layer 114 is made of an inorganic material, the dielectric constant is high. Although it can be used and the dielectric breakdown voltage is high, but the surface is not hydrophobic, the surface should be coated with a hydrophobic polymer or hydrophobic treatment.

The solution includes a transparent aqueous solution 131 and an opaque organic solution 132. Here, as the aqueous solution 131, an aqueous solution in which distilled water or an electrolyte is dissolved may be used. The organic solution 132 should have hydrophobicity to cause the electrowetting phenomenon. In addition, since the organic solution 132 should be able to block all of the red (R), green (G), and blue (G) light emitted from the backlight unit 100, the organic solution 132 may block such light. Inorganic or organic matter which may be present. Here, for example, carbon black may be used as an inorganic material that may block light of red (R), green (G), and blue (G), and an organic dye may be used as an organic material. Pigments and the like can be used. In addition, the organic solution 132 may include a material of a color filter currently used in a liquid crystal display (LCD). The organic solution 132 may be, for example, black oil. Here, black ink may be used as the black oil, and carbon black may be contained in the black ink.

Meanwhile, a plurality of partition walls 115 are provided between the first substrate 110 and the second substrate 120. These partitions 115 serve to maintain a constant gap between the first substrate 110 and the second substrate 120. In addition, a space between the first substrate 110 and the second substrate 120 may be partitioned by the partitions 115 to form a plurality of pixels. Here, each of the pixels may be formed to have a size of approximately 300 μm or less.

In the optical shutter 150 having the structure described above, when a predetermined voltage is applied between the first electrode 112 and the second electrode 122, the dielectric layer 114 having the hydrophobic surface is changed to hydrophilic, so that the aqueous solution 131 The area in contact with the dielectric layer 114 is increased. Accordingly, the organic solution 132 moves to a region where no voltage is applied at a high speed. As described above, the exemplary embodiment switches the light of a predetermined color emitted from the backlight unit 100 using the optical shutter 150 using the electrowetting phenomenon. The optical shutter 150 using the electrowetting phenomenon is much faster than the case of the liquid crystal. Specifically, in the present invention, the moving speed of the organic solution 132 that determines the response speed of the optical shutter 150 may be about 0.1 cm / sec to about 5 cm / sec. In the display device according to the present invention, when the size of the pixel is 100 μm, for example, if the moving speed of the organic solution 132 is about 2.5 cm / sec, the response speed of the optical shutter 115 may be about 4 ms. Can be.

4A and 4B are diagrams for describing an operation process of the optical shutter 115 in the display device according to the exemplary embodiment of the present invention. 4A illustrates a state in which no voltage is applied between the first electrode 112 and the second electrode 122. FIG. 4B illustrates a predetermined voltage between the first electrode 112 and the second electrode 122. The state where V ₁ is applied is shown.

First, referring to FIG. 4A, when no voltage is applied between the first electrode 112 and the second electrode 122, the interfacial energy of the organic solution 132 and the aqueous solution 131, the organic solution 132, and the like. Since the sum of the interfacial energy of the dielectric layer 114 is smaller than the sum of the interfacial energy of the aqueous solution 131 and the dielectric layer 114, the organic solution 132 covers the entire dielectric layer 114, and the aqueous solution is disposed on the organic solution 132. 131 is located. Accordingly, the light emitted from the backlight unit 100 is blocked by the opaque organic solution 132 to prevent the pixel from passing through. Next, referring to FIG. 4B, when a predetermined voltage, for example, V ₁ is applied between the first electrode 112 and the second electrode 122, the dielectric layer 114 and the organic solution 132 having a hydrophobic surface are present. The contact characteristics between them will change. Specifically, the area in which the aqueous solution 131 contacts the dielectric layer 114 is increased by changing the hydrophobic dielectric layer 114 having a hydrophobic surface. Accordingly, the organic solution 132 is moved at a high speed around the area where no voltage is applied, for example, the partition wall 115. As a result, the light of a predetermined color emitted from the backlight unit 100 passes through the transparent aqueous solution 131 in the pixel and goes out.

On the other hand, in the display device according to an embodiment of the present invention, gray scale of each pixel by adjusting the magnitude of the voltage applied between the first electrode 112 and the second electrode 122 as shown in FIG. Can be adjusted. Referring to FIG. 5, when a voltage smaller than the above-described voltage V ₁ , for example V ₂ (<V ₁ ) is applied between the first electrode 112 and the second electrode 122, the organic solution may be used. 132 moves to cover only a portion of the dielectric layer 114 in the pixel. Accordingly, the light emitted from the backlight unit 100 passes through the dielectric layer 114 which is not covered by the organic solution 132 in the pixel and exits to the outside. As such, when the magnitude of the voltage applied between the first electrode 112 and the second electrode 122 is adjusted, an area of the dielectric layer 114 covered with the organic solution 132 may be adjusted. Accordingly, the amount of light transmitted through each pixel can be adjusted, and as a result, the gray level of each pixel can be adjusted.

6 illustrates a modification of a partition wall that may be applied to a display device according to an exemplary embodiment of the present invention. Referring to FIG. 6, a lower portion of the partition wall 115 ′ is thinner than an upper portion of the partition wall 115 ′. As such, when the lower portion of the partition wall 115 'is formed thinner than the upper portion, the opaque organic solution 132 may move to enter the lower portion of the partition wall 115'. As a result, it is possible to further increase an area through which light is transmitted in the pixel.

7 is a diagram schematically illustrating a display device according to another embodiment of the present invention. Hereinafter, only differences from the above-described embodiment will be described.

Referring to FIG. 7, a display apparatus according to another exemplary embodiment includes a backlight unit 200 and an optical shutter 250 for switching light emitted from the backlight unit 200. As the backlight unit 200, a field sequential light source driven in a sequential manner as described above is used.

The optical shutter 250 is installed in front of the backlight unit 200 to switch light of a predetermined color emitted from the backlight unit 200. As described above, the optical shutter 250 switches light of a predetermined color emitted sequentially by using the electrowetting phenomenon. The optical shutter 250 includes first and second substrates 210 and 220 spaced apart from each other at regular intervals, and a plurality of first electrodes 212 formed on an inner surface of the first substrate 210; A dielectric layer 214 formed on an inner surface of the first substrate 210 to cover the first electrode 212, a plurality of second electrodes 222 formed on an inner surface of the second substrate 220, and And a solution filled between the second electrodes 222 and the dielectric layer 214.

In general, a glass substrate or a plastic substrate may be used as the first and second substrates 210 and 220. In the present embodiment, a plurality of first electrodes 212 is formed corresponding to one pixel. Although not shown in the drawing, a switching element for switching the applied voltage is connected to each of the first electrodes. The first electrodes 212 may be, for example, formed in a stripe shape or in a dot shape. In addition, the first electrodes 212 may be formed in various shapes. The second electrodes 222 may be, for example, formed in a stripe shape or may be integrally formed to cover the bottom surface of the second substrate 220. In addition, the second electrodes 222 may be formed in various shapes. The first and second electrodes 212 and 222 may be made of a transparent conductive material. As described above, the dielectric layer 214 is made of a transparent material, and the surface thereof is preferably hydrophobic. The solution includes a transparent aqueous solution 231 and an opaque organic solution 232. A plurality of partitions 215 are provided between the first substrate 210 and the second substrate 220. Meanwhile, the partitions 215 may have a lower portion thinner than an upper portion, as shown in FIG. 6.

Hereinafter, an operation process of the optical shutter in the display device according to another embodiment of the present invention will be described.

FIG. 7 illustrates a state in which no voltage is applied between the first electrode 212 and the second electrode 222. 8A and 8B are diagrams illustrating an operation process of the optical shutter 250 when a predetermined voltage is applied between the first electrode 212 and the second electrode 222.

Referring to FIG. 7, when no voltage is applied between the first electrodes 212 and the second electrode 222, the organic solution 232 covers the entire dielectric layer 214 and the organic solution 214. The aqueous solution 231 is positioned above. Accordingly, the light emitted from the backlight unit 200 is blocked by the opaque organic solution 232 to prevent the pixel from passing through.

Next, a predetermined voltage, for example, V is applied between the first electrodes 212 and the second electrode 222. In this case, as illustrated in FIG. 8A, first voltages are applied to voltages applied to four first electrodes 212 positioned in a pixel, for example, among the plurality of first electrodes 212 constituting one pixel. When controlling 212, the organic solution 232 is moved around an area where no voltage is applied, that is, around the partitions 215. Control of such first electrodes 212 is achieved by switching the voltage applied to each of the first electrodes 212. Accordingly, most of the light emitted from the backlight unit 200 passes through the pixel and goes out.

As shown in FIG. 8B, first voltages are applied such that voltage is applied only to two first electrodes 212 positioned among pixels, for example, among the plurality of first electrodes 212 constituting one pixel. When controlling 212, the organic solution 232 moves to a region where no voltage is applied. In this case, since the area of the organic solution 232 covering the dielectric layer 214 is larger than the area of the organic solution 232 covering the dielectric layer 214 in FIG. 8A, light emitted from the backlight unit 200 and transmitted through the pixel is transmitted. Is reduced than in FIG. 8A.

As described above, in the present exemplary embodiment, an area in which the dielectric layer 214 is covered with the organic solution 232 may be controlled by controlling the first electrodes 212 corresponding to one pixel. Accordingly, the amount of light transmitted through each pixel can be adjusted, and as a result, the gray level of each pixel can be adjusted. As in the present embodiment, when the plurality of first electrodes 212 are formed to correspond to one pixel and each of the first electrodes 212 is controlled, a desired area of the organic solution 232 is desired. Since it is easy to move to, the gray scale of each pixel can be made easier than in the above-described embodiment, and the response speed of the optical shutter 250 can be improved.

Hereinafter, a process of implementing an image by the display apparatus according to the present invention will be described. Hereinafter, when the display device according to the present invention forms 60 frames for 1 second, one frame is composed of four R / G / B / Black subframes sequentially driven. An example will be described.

FIG. 9 illustrates that light of a predetermined color is sequentially emitted from the field sequential light source used as the backlight unit in the present invention. Referring to FIG. 9, the field sequential LEDs sequentially emit red (R) / green (G) / blue (B) / black (Black) light per frame, and light of each color is emitted for 4 ms. do.

10A to 10D sequentially illustrate a process of implementing an image when light of a predetermined color is emitted from a backlight unit including a field sequential light source, as shown in FIG. 9, in the display device according to the present invention. Referring to the drawings, the red light R is first emitted from the backlight unit, and the emitted red light R passes through predetermined pixels through the driving of the optical shutter using the electrowetting phenomenon and comes out for 4 ms (FIG. 10a). Next, the green light G is emitted from the backlight unit, and the emitted green light G passes through predetermined pixels selected by the driving of the light shutter for 4 ms (Fig. 10B). Subsequently, blue light B is emitted from the backlight unit, and the emitted blue light B passes through predetermined pixels selected by the driving of the optical shutter for 4 ms (FIG. 10C). Finally, the backlight driving is cut off, so that black light is emitted from all pixels for 4 ms (FIG. 10D). As such, when the red (R) / green (G) / blue (B) / black (Black) light is sequentially transmitted through the selected pixels for 4 ms each, an image is formed due to the afterimage effect.

Although the preferred embodiment according to the present invention has been described above, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

 As described above, the display apparatus according to the present invention uses a field sequential light source driven in a sequential manner as a backlight unit, and sequentially emits light emitted from the backlight unit to an optical shutter using an electrowetting phenomenon with a fast response speed. By switching, a desired image can be realized. In addition, since the display device according to the present invention does not require a color filter in a conventional liquid crystal display device, the optical loss is significantly reduced compared to a liquid crystal display device having a color filter, so that low power can be driven, and there is no limitation of a viewing angle. The production time and cost of the advantage is reduced.

Claims (21)

A backlight unit including a field sequential light source driven in a sequential manner; And an optical shutter provided at the front of the backlight unit to switch the light emitted from the backlight unit and using an electrowetting phenomenon. The method of claim 1, The optical shutter is First and second substrates spaced apart from each other at regular intervals; A plurality of first electrodes formed on an inner surface of the first substrate; A dielectric layer formed on the first substrate to cover the first electrodes; A plurality of second electrodes formed on an inner surface of the second substrate; And a transparent aqueous solution and an opaque organic solution filled between the second electrodes and the dielectric layer. The method of claim 2, The optical shutter is configured to switch light of a predetermined color emitted from the backlight unit for each pixel while the organic solution moves by applying a predetermined voltage between the first electrode and the second electrode. The method of claim 3, wherein And a gray scale of each pixel by adjusting the magnitude of the voltage applied between the first electrode and the second electrode. The method of claim 3, wherein And a plurality of second electrodes formed corresponding to one pixel. The method of claim 5, And controlling the gray scale of each pixel by controlling the second electrodes to switch a voltage applied to each of the second electrodes. The method of claim 3, wherein And the pixels have a size of 300 μm or less. The method of claim 2, And a plurality of partition walls are formed between the first substrate and the second substrate to partition the space between the first substrate and the second substrate to form pixels. The method of claim 8, And a lower portion of the barrier rib is formed thinner than an upper portion of the barrier rib so that the organic solution can move and enter the lower portions of the barrier ribs. The method of claim 2, And the first and second substrates are transparent substrates. The method of claim 2, And the first electrodes are formed parallel to each other. The method of claim 11, And the second electrodes are formed to be parallel to each other in a direction crossing the first electrodes. The method of claim 2, And the first and second electrodes are made of a transparent conductive material. The method of claim 13, And the first and second electrodes are made of indium tin oxide (ITO) or ZnO. The method of claim 2, And the dielectric layer has a hydrophobic surface. The method of claim 2, Display apparatus, characterized in that the movement speed of the organic solution is 0.1cm / sec ~ 5cm / sec. The method of claim 2, And the organic solution is black oil. The method of claim 17, And black ink as the black oil. The method of claim 18, And the black ink contains carbon black. The method of claim 1, The field sequential light source sequentially emits red (R) / green (G) / blue (B) / black (Black) light for each frame. The method of claim 1, The field sequential light source sequentially emits red (R), black (black), green (G), black (black), blue (B), and black (Black) light every frame. .

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