KR101061902B1 - Display device using photonic crystal characteristics - Google Patents

Abstract

A display device using the photonic crystal characteristic is disclosed. The display device 10 includes a recording unit 100 for generating magnetism; A storage unit 300 for storing a predetermined amount of magnetism according to the strength of the magnetism generated from the recording unit 100; And a display unit 200 disposed adjacent to the storage unit 300 and determining a wavelength of the reflected light according to the intensity of the magnetic stored in the storage unit 300. In particular, the display device 10 may include a superparamagnetic cluster coated with a photonic crystal in the display unit 200.

Display, Photonic Crystal, Superparamagnetic, Polymer, Writing Board

Description

Display device using photonic crystal characteristics {DISPLAY DEVICE USING PHOTOCRYSTAL CHARACTERISTICS}

The present invention relates to a display device using photonic crystal characteristics. More specifically, the writing board can be easily written in various colors by changing the wavelength of the light reflected from the display as the distance between the polymer-coated superparamagnetic clusters used as the photonic crystal is changed by the intensity of the magnet generated from the recording unit. It is about.

In general, writing boards, that is, blackboards used in schools, academies, and companies are divided into black boards that can be written using chalk and white boards that can be written using a thick aqueous pen.

However, in the case of a black blackboard, when the writing or the writing is erased, indoor air is contaminated by chalk powder, which may threaten the health of educators and students. In addition, the white board needs to be closed at all times after writing, so it is cumbersome, smells of chemical solvents, can be easily lost during use, and the pen needs to be replaced frequently because the pen is quickly consumed. As time went by, there was a problem such as a fading color of the white blackboard. In addition, both black and white blackboards have a problem in that the writing tools (chalk, water pen) are limited in color, so that they cannot be written in various colors on the blackboard.

The electronic blackboard has been developed to solve the problems of the existing black or white blackboard as described above. An electronic blackboard is a conductive blackboard which is usually made of a conductive flat surface, and can be written using an electronic pen. However, the electronic blackboard has a problem in that it is limited in the place of use because the composition of the device is complicated and expensive, so that its general purpose is greatly reduced, and a power source is required.

Accordingly, an object of the present invention is to provide a writing board that can be written in various colors using one writing tool.

In addition, an object of the present invention is to provide an environment-friendly writing board that does not generate dust or smell of chemical solvents.

In addition, an object of the present invention is to provide a writing board that requires no power supply and can use a semi-permanent board and writing tool, which is low in maintenance cost.

In addition, an object of the present invention is to provide a writing board having a low cost and high versatility with a simple configuration and easy manufacturing.

Moreover, an object of this invention is to provide the large area writing board which can use a flexible substrate, and is easy to move and store.

In order to achieve the above object, the display device according to the present invention is characterized in that it comprises a photonic crystal layer containing a superparamagnetic (superparamagnetic).

In order to achieve the above object, the display device according to the present invention includes a recording unit for generating a magnet; A storage unit for storing a predetermined amount of magnetism in accordance with the strength of magnetism generated from the recording unit; And a display unit disposed adjacent to the storage unit and configured to determine a wavelength of reflected light according to the intensity of magnetism generated from the recording unit or the intensity of the magnetism stored in the storage unit.

The base unit may be further disposed below the storage unit.

The substrate portion may be a flexible substrate.

The recording unit includes a permanent magnet, and the intensity of the magnetic force generated from the recording unit may vary according to the installation position of the permanent magnet in the recording unit.

The recording unit includes an electromagnet wound with a coil, and the intensity of the magnetic force generated from the recording unit may vary according to the amount of current flowing through the coil in the recording unit.

The recording unit may be connected with means for precisely controlling the position of the recording unit.

The display unit may include superparamagnetic clusters coated with a charge generating material.

The superparamagnetic body may include at least one of iron oxide, nickel oxide, and cobalt oxide.

The charge generating material may include a negative charge generating material including PAA (polyacrylic acid) or a positive charge generating material including polyvinyl pyridine and polystyrene sulfonate.

The polymer-coated superparamagnetic cluster within the indicator may be in a colloidal state.

The distance between the polymer-coated superparamagnetic clusters in the display unit may vary according to the magnetic intensity generated from the recording unit, and the wavelength of light reflected from the display unit may change according to the change of the distance.

The storage unit may include a ferromagnetic material including at least one of iron, nickel, and cobalt.

According to the present invention, one writing tool can be written in various colors, and an eco-friendly, semi-permanent writing tool can be used that does not compromise the user's health, so the maintenance cost is low, the composition is simple, and the manufacturing is easy. Therefore, it is possible to obtain a low cost and high versatility regardless of the place of use.

DETAILED DESCRIPTION The following detailed description of the invention refers to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. Like reference numerals in the drawings refer to the same or similar functions throughout the several aspects.

The writing board 10 according to the present invention has a main technical feature of being able to implement full color letters by providing a photonic crystal therein. here. Photonic crystal refers to a crystal that reflects light of a specific wavelength and emits color according to the wavelength, and passes light of the remaining wavelength. For example, a butterfly has a pigment but does not have a pigment on its back shell. Because it can give a distinctive color.

According to a recent study on photonic crystals, compared to conventional photonic crystals reflecting only one light, newly synthesized photonic crystals containing a predetermined material can be formed by crystallization of photonic crystals (eg, photonic crystals) through electrical, magnetic or chemical stimulation. The interlayer thickness) can be freely changed, and as a result, the wavelength of light can be freely controlled not only in the visible light region but also in the ultraviolet or infrared region.

In addition, a recent article by Jianping, Ge et al. ("Highly Tunable Superparamagnetic Colloidal Photonic Crystals", Angew. Chem. Int. Ed. 2007, 46, 7428-7431) discloses a superparamagnetic material having photonic crystal properties. have. According to this paper, iron oxide (Fe ₃ O ₄ ) clusters coated with colloidal polyacrylic acid (PAA) (the size of the cluster can be adjusted to 30 to 180 nm, and each cluster has a plurality of approximately 10 nm iron oxide nanoparticles. It can be used as a photonic crystal that can control the wavelength of the reflected light over the entire visible light region.

This is because the attraction between the clusters due to the superparamagnetism of iron oxide when the external magnetic field is applied, and the repulsive force between the clusters by the negatively charged PAA coating layer acts as a colloidal state according to the strength of the external magnetic field. Because you can adjust. In other words, according to Bragg's law, since the wavelength of light reflected from the clusters is determined by the distance between the clusters, the wavelength of the light reflected from the clusters may be changed according to the distance between the clusters.

Therefore, the inventor of the present invention, if the magnetic field applied to the colloidal PAA-coated iron oxide (Fe ₃ O ₄ (magnetite)) cluster as described above can vary the wavelength of the light reflected from the cluster according to the strength of the magnetic field The present invention has been made with the idea that applying this to a display device can realize a full color image.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, in order that those skilled in the art can easily carry out the present invention.

1 is a view showing the configuration of a writing board 10 according to an embodiment of the present invention. As illustrated, the writing board 10 includes a recording unit 100, a display unit 200, and a storage unit 300 in a basic configuration.

First, the recording unit 100 is a configuration corresponding to writing means in the writing board 10. In the present invention, as described above, the recording unit 100 employs a photonic crystal for changing the wavelength of reflected light by applying a magnetic field. It is desirable to take a configuration capable of generating a variable magnetic field, that is, a configuration capable of adjusting the intensity of the generated magnetic field.

2A and 2B are diagrams showing the configuration of the recording unit 100 according to an embodiment of the present invention.

Referring to FIG. 2A, the recording unit 110 may be manufactured in a configuration including a permanent magnet 112 generating a magnetic field and a case 114 storing the magnetic field. In this case, although not shown in detail, the case 114 may be manufactured in the form of a writing tool, for example, a chalk used on a black chalkboard or a water-based pen used on a white chalkboard. In addition, the case 114 may be provided with a permanent magnet position changing means (not shown) to freely change the position where the permanent magnet 112 is disposed in the case 114. As such, by changing the position of the permanent magnet 112 in the case 114, the intensity of the magnetic field generated from one end of the recording unit 110 in contact with the display unit 200 may be adjusted. For example, in FIG. 3A, the intensity of the magnetic field applied from the display unit 200 is greater than that of the left figure.

Referring to FIG. 2B, the recording unit 120 includes an electromagnet 122 in which a coil 126 generating a magnetic field is wound, a power source (not shown) for flowing a current through the coil 126, and a case 124 storing the same. It may be manufactured in a configuration including). In this case, the shape of the case 124 may be manufactured in the form of chalk or an aqueous pen as described in FIG. 2A. As described above, according to the configuration of FIG. 2B, the intensity of the magnetic field induced from the electromagnet 122 may be changed by adjusting the amount of current supplied to the coil 126. The intensity of the magnetic field generated from one end of the recording unit 120 may be adjusted.

Meanwhile, the recording unit 100 may serve as an eraser as well as a pen that can be written in various colors on the writing board 10. For example, the permanent magnet 112 mounted in the case of the recording unit 110 has two magnetic poles, so if one magnetic pole is used for the purpose of the pen, the opposite magnetic pole is marked with a pen. It can be used as an eraser to reset a specific color of text. In other words, when the recording unit 110 used as a pen is turned upside down, the recording unit 110 serves as an eraser. In the case of the recording unit 120, the role of the recording unit 120 can be easily changed from a pen to an eraser by changing the direction of the current flowing to the coil 126. The detailed principle of the writing and erasing operation using the recording unit 100 in the writing board 10 will be described later.

Next, the display unit 200 is a configuration corresponding to the display means that is actually written on the writing board 10, in the present invention, as described above, includes a photonic crystal for changing the wavelength of the reflected light by applying a magnetic field, It is preferable to use a colloidal polyacrylic acid (PAA) coated iron oxide cluster as the photonic crystal.

3A and 3B are views showing the configuration of a PAA-coated iron oxide cluster applied to the writing board 10 as a photonic crystal according to an embodiment of the present invention, which is disclosed in the above-mentioned paper as a related art. ,

FIG. 3A shows a TEM image of the cluster, in which a PAA-coated iron oxide cluster 210 having a size of approximately 100 nm is uniformly dispersed in a colloidal state in a predetermined solvent 220 such as, for example, water. Since the method for manufacturing the cluster shown in the TEM photograph is disclosed in the above-mentioned paper, a detailed description thereof will be omitted herein. 3B is a schematic diagram of the cluster, in which a plurality of iron oxide nanocrystals 212 form a cluster 210 and a surface of which a negatively charged PAA layer 214 is coated.

As described above, although the iron oxide cluster is used as the photonic crystal in the present invention, the present invention is not limited thereto, and may be a superparamagnetic material including at least one of iron (Fe) oxide, nickel (Ni) oxide, and cobalt (Co) oxide. . Here, a superparamagnetic substance is a substance in which magnetization disappears by thermal motion when no external magnetic field is applied, whereas a degree of magnetization induced when an external magnetic field is applied is much larger than a paramagnetic substance. However, under the critical magnetic field, it is a substance that exhibits a self-saturation phenomenon similar to a ferromagnetic substance. Although there are differences depending on the material, when the particle size of the ferromagnetic material becomes small from several nanometers to several hundred nanometers, the phase transition to the superparamagnetic body has magnetic properties different from the bulk state.

In addition, although PAA is used as a coating material of the superparamagnetic cluster, the material is not limited thereto, and may be a material capable of generating charge so that the superparamagnetic clusters may be uniformly dispersed in a solvent. Therefore, in addition to the negative charge generating materials such as PAA, positive charge generating materials such as polyvinyl pyridine and polystyrene sulfonate are also possible. Although a polymer (polymer) is mentioned as an example of the charge generating material in the above, a unit (monomer) or an inorganic material is also possible.

By adopting the configuration of the display unit 200, the distance between the colloidal PAA-coated iron oxide clusters included in the display unit 200 is changed according to the variable magnetic field generated from the recording unit 100, and as a result, the display unit 200 is changed. The wavelength of the light reflected from it can be adjusted. Therefore, when a user writes letters or the like on the display unit 200 using the recording unit 100 as a writing means, the color of the displayed letters becomes a specific color by the action of the photonic crystal included in the display unit 200, FIGS. If the intensity of the magnetic field generated using the recording units 110 and 120 as shown in FIG. 2B can be properly adjusted, full-color letters may be displayed on the display unit 200.

In this case, the display unit 200 is preferably manufactured in a form that is physically isolated from the external environment so that the PAA-coated iron oxide clusters in the colloidal state do not flow out of the display unit 200. In addition, a polymer film layer (not shown) may be further provided on the surface of the display unit 200 to protect the display unit 300.

Next, the storage unit 300 is a means for storing the magnetic field generated from the recording unit 100 in the writing board 10, in the present invention, as described above, the display unit 200 only when the externally applied magnetic field is maintained. This is necessary because the photonic crystal in) exhibits full color characteristics. If the writing board 10 does not have a storage unit 300 installed therein and then records the letters on the display unit 200 with the recording unit 100 and then isolates the recording unit 100 from the display unit 200. The distance between the iron oxide clusters in the display unit 200 set by the magnetic field generated by the recording unit 100 can no longer be maintained, thereby causing a problem such that the color of the written font changes immediately. It will not work.

Therefore, in the present invention, the storage unit 300 formed of a ferromagnetic material containing at least one of iron, nickel, and cobalt is provided below the display unit 200, so that the recording unit 100 as a magnetic field generating source is isolated from the display unit 200. (I.e., after the external magnetic field source disappears), a certain distance between the iron oxide clusters set by the magnetic field (i.e., the internal magnetic field source) generated from the storage unit 300 which maintains the magnetization state can be maintained. Problems occurring when the same storage unit 300 is not installed can be solved.

The storage unit 300 may be disposed to be closest to the display unit 200. Referring to FIG. 1, the storage unit 300 may be installed to be in contact with the display unit 200 under the display unit 200. desirable. In this case, however, a stabilization layer (not shown) is provided between the display unit 200 and the storage unit 300 in order to suppress an unwanted reaction between the two components that may occur due to the direct contact between the display unit 200 and the storage unit 300. Can be installed additionally.

On the other hand, in terms of improving the resolution of the writing board 10, it may be desirable to form a structure in which the ferromagnetic material constituting the storage unit 300 is isolated in a fine unit.

Next, the base unit 400 is provided below the storage unit 300 in the writing board 10 and corresponds to the support means for supporting the display unit 200 and the storage unit 300. The material of 400 is not particularly limited as long as the display unit 200 and the storage unit 300 can be fixedly supported. However, the material of the writing board is preferably made of an inexpensive material. When considering, it is preferable to be made of a material having a small weight, and when considering the mobility of the writing board, a material having flexibility is preferable. In particular, if the flexible substrate can be used as the base unit 400, it is possible to implement a large-area writing board that is easy to move and store. In addition, for example, a titanium (Ti) adhesive layer (not shown) may be additionally provided between the storage unit 300 and the base unit 400 to improve adhesion between them.

The principle of the actual writing and erasing operation in the writing board 10 including the recording unit 100, the display unit 200, and the storage unit 300 as described above will be described in detail with reference to FIGS. 4A to 4D. Is as follows.

First, FIG. 4A is a diagram schematically illustrating a writing operation in the writing board 10. As shown in the drawing, the writing unit 100 including the permanent magnet is used as a writing means, so that the writing is made as close as possible to the board consisting of the display unit 200 / storage unit 300, or in direct contact with the board. .

In this process, magnetism generated from the permanent magnet of the recording unit 100 magnetizes the storage unit 300. 4B is a diagram illustrating the degree M of storage 300 being magnetized according to the change of magnetism H generated in the recording unit 100. As shown, if the strength of the magnetic field of the recording unit 100 is H _{b, the} storage unit 300 is magnetized to M _b . Similarly, if the strength of the magnetic field of the recording unit 100 is H _c , H _d , the storage unit 300 is provided. Is magnetized to M _c , M _d . At this time, the strength of the magnetic generated in the recording unit 100 can be adjusted by changing the position of the permanent magnet in the recording unit 100 as described above.

The wavelength of the reflected light on the display unit 200 changes according to the magnetization degree of the storage unit 300 as described above. 4C is a view illustrating a change in the wavelength of reflected light in the display unit 200 according to the degree of magnetization of the storage unit 300. As shown, when the storage unit 300 is magnetized to Mc, the wavelength of the reflected light in the display unit 200 becomes C _c (green-based light). Similarly, when the storage unit 300 is magnetized to M _d , the display unit ( The wavelength of the reflected light at 200 becomes C _d (blue light).

Therefore, referring to FIG. 4A, when the recording unit 100 generates the magnetism of H _c during the writing process, the storage unit 300 magnetizes to M _c , and as a result, the light of the wavelength C _c is reflected by the display unit 200. On the dragon board 10 it is possible to mark the letters of the green color.

On the other hand, in the writing process, the font color of the display may change instantaneously as the distance between the recorder and the display / storage changes, but when the recorder is closest to the display / storage, the strength of the magnetization that magnetizes the storage. Since the size is the largest, the writing instrument (recording unit) is in contact with the board (display unit / storage unit), the intensity of the magnetic field at the time of recording can be written in a specific color.

The erase process is done using the magnetism of the writing process and the opposite stimulus. 4D is a diagram schematically illustrating an erase operation in the writing board 10. As shown, the erase process in the writing board 10 is performed by stimulating the magnetic pole of the permanent magnet in contact with the display unit 200 in the recording unit 100 as opposed to the writing process. That is, as illustrated in FIG. 4A, when the writing process is performed by contacting the N pole of the permanent magnet with the display unit 200, the erasing process is performed by contacting the S pole of the permanent magnet with the display unit 200 (of course, the writing process). If the S pole of the permanent magnet is in contact with the display unit, the N pole of the permanent magnet is in contact with the display unit in the erasing process. At this time, the intensity of the magnetism generated in the recording unit 100 is made to be the minimum (Hr), so that the storage unit 300 is magnetized up to (Mr), so that the wavelength of the reflected light on the display unit 200 is always C _(Mr) In this case, it is desirable that the display unit always display a specific color when the erasing process is completed.

According to the writing board of the present invention employing the above-described colloidal PAA-coated iron oxide cluster as a photonic crystal, it is possible to write full color even if only one writing tool is used, and it is eco-friendly, which does not damage the user's health, Since semi-permanent writing tools can be used, the maintenance cost is low, the configuration is simple, and the manufacturing is easy.

Meanwhile, as described above, the writing board has been described as an application example of the iron oxide cluster coated with the colloidal charge generating material, but is not necessarily limited thereto. That is, by attaching a recording unit implemented in the form of FIGS. 2A and 2B to a mechanically moving device or by combining it with a driving circuit such as a transistor having a constant arrangement, only changing the color of a specific position by inducing a magnetic change at a specific position. It can be implemented in printers and displays.

As an example in this regard, the technical idea of the present invention, that is, the concept of implementing a full color display using the photonic crystal characteristic, takes the configuration of a recording unit (magnetic field source) whose position can be precisely controlled by a properly controlled moving means. This makes it possible to apply to a magnetic printer. That is, since the intensity of the magnetic field generated from the recording unit can be adjusted according to the position of the recording unit, a magnetic printer capable of expressing full-color letters and images on the printing paper containing the iron oxide cluster can be implemented. Such a magnetic printer can easily enable full color printing on e-paper, which is expected to increase in frequency in the future.

Furthermore, as another example, the technical idea of the present invention is to apply to a magnetic display by taking the configuration of a recording unit (magnetic field source) that generates magnetism at any position of the XY panel in combination with a properly controlled transistor. This is possible. That is, in this case, only a storage unit corresponding to a specific transistor to be accessed among the XY array type transistors driving the display can be magnetized as applied in magnetic random access memory (MRAM) or the like, and as a result, the display unit has a specific color. A magnetic display capable of displaying an image can be implemented.

As described above, the present invention has been described by specific embodiments such as specific components and the like. For those skilled in the art to which the present invention pertains, various modifications and variations are possible.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and all of the equivalents or equivalents of the claims as well as the claims to be described later will belong to the scope of the present invention. .

1 is a view showing the configuration of a writing board according to an embodiment of the present invention.

2A and 2B show a configuration of a recording unit according to an embodiment of the present invention.

3A and 3B are views showing the configuration of a polymer-coated superparamagnetic cluster applied to a writing board according to an embodiment of the present invention as a photonic crystal.

4A to 4D are diagrams illustrating principles of writing and erasing operations of a writing board according to an embodiment of the present invention.

<Brief description of the major reference numerals>

10: display device (writing board)

100, 110, 120: register

112: permanent magnet

114, 124: case

122: electromagnet

126: coil

200: display unit

210: superparamagnetic cluster

220: solvent

300: storage

400: substrate

Claims (13)

A recording unit generating magnetism; A storage unit for storing a predetermined amount of magnetism in accordance with the strength of magnetism generated from the recording unit; And The display unit is disposed adjacent to the storage unit and the wavelength of reflected light is determined according to the intensity of magnetism generated from the recording unit or the strength of the magnetism stored in the storage unit. Including, And the recording unit includes a permanent magnet, and the intensity of the magnetic force generated from the recording unit varies according to the installation position of the permanent magnet in the recording unit. A recording unit generating magnetism; A storage unit for storing a predetermined amount of magnetism in accordance with the strength of magnetism generated from the recording unit; And The display unit is disposed adjacent to the storage unit and the wavelength of reflected light is determined according to the intensity of magnetism generated from the recording unit or the strength of the magnetism stored in the storage unit. Including, And the recording unit includes an electromagnet in which a coil is wound, and the intensity of magnetism generated from the recording unit varies according to the amount of current flowing through the coil in the recording unit. The method according to claim 1 or 2, And a base unit disposed under the storage unit. The method of claim 3, And the base portion is a flexible substrate. delete delete The method according to claim 1 or 2, And a means for precisely controlling the position of the recording portion is connected to the recording portion. The method according to claim 1 or 2, And the display unit includes superparamagnetic clusters coated with a charge generating material. The method of claim 8, The superparamagnetic body may include at least one of iron oxide, nickel oxide, and cobalt oxide. The method of claim 8, The charge generating material may include a negative charge generating material including a polyacrylic acid (PAA) or a positive charge generating material including a polyvinyl pyridine and polystyrene sulfonate. The method of claim 8, And the polymer-coated superparamagnetic cluster in the display unit is in a colloidal state. The method of claim 8, And the distance between the polymer-coated superparamagnetic clusters in the display unit varies according to the intensity of the magnetic field generated from the recording unit, and the wavelength of the light reflected from the display unit changes according to the change of the distance. The method according to claim 1 or 2, And the storage unit comprises a ferromagnetic material including at least one of iron, nickel, and cobalt.

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