KR20160090588A - Electronic paper display device - Google Patents

Abstract

The present disclosure relates to a lower piezoelectric substrate on which a first electrode is disposed on an upper surface thereof; A plurality of display elements disposed on the lower piezoelectric substrate; And a second electrode disposed on the display element.

Description

[0001] The present invention relates to an electronic paper display device,

The present disclosure relates to an electronic paper display device.

Today, a large paradigm is required for the information society, and information exchange and sharing methods are required. To meet this demand, the development of electronic paper with the advantage of being flexible as a flexible display is accelerating, and the development of electronic paper technology is entering commercial development stage.

Electronic paper is less expensive than conventional flat panel display panels, and can be driven with very little energy, which is far superior to energy efficiency. In addition, the electronic paper is very clear, has wide viewing angle, and has a memory function that does not completely disappear even if there is no power source. Because of these great advantages, electronic paper can be applied to a wide range of fields, such as electronic books with paper-like faces and moving illustrations, self-renewal newspapers, reusable paper displays for mobile phones, disposable TV screens and electronic wallpaper And has a huge potential market.

The technical approach for the implementation of electronic paper can be classified into four kinds: twist ball method in which spherical particles composed of upper and lower hemispheres having opposite charges and different colors are rotated using an electric field, An electrophoresis method in which particles are confined in a microcapsule or a microcup, an electrophoresis method in which charged particles are left as they are in response to application of an electric field, a QR-LPD (Quick Response-Liquid Power Display) And a cholesteric liquid crystal display method using selective reflection characteristics of the liquid crystal display.

Among them, electronic paper using a microcapsule type electrophoresis method is widely used.

Electrophoresis refers to the transfer of charged materials in a fluid medium under the influence of an electric field.

The structure of the microcapsule-type electronic paper is generally sandwiched between two sheets of electrode substrates with transparent fluids and transparent capsules filled with different charge-charged white and black particles.

When the electronic paper is driven by electrophoresis, the white and black particles of the electronic ink are moved to the upper and lower electrodes by the applied voltage. Then, even if the voltage application is stopped, the white and black particles are positioned on the electrode surface to express color due to the bistability of the electronic paper.

However, during such operation, the white or black particles are agglomerated on the electrode surface. In addition, when the electronic paper is driven, particles are clustered in the electronic ink.

This affects the contrast ratio, operating voltage and reliability of the electronic paper.

Likewise, the microcup type is manufactured by injecting electronic ink composed of white and black particles charged with different charges by forming partition walls instead of capsules. The driving method is the same as the capsule type.

Therefore, there is a need for a method for preventing the above-mentioned aggregation of particles.

Japanese Patent Application Laid-Open No. 2013-238862

The present disclosure seeks to provide an electronic paper display device capable of improving the aggregation of particles.

An electronic paper display device according to an embodiment of the present disclosure includes: a lower piezoelectric substrate on which a first electrode is disposed; A plurality of display elements disposed on the lower piezoelectric substrate; And a second electrode disposed on the display element.

The present disclosure can improve the aggregation of particles by forming a substrate of an electronic paper display device using a piezoelectric substrate.

1 shows a schematic cross-sectional view of an electronic paper display device according to one embodiment of the present disclosure using microcapsules.
Figure 2 shows a schematic cross-sectional view of an electronic paper display device according to one embodiment of the present disclosure using a microcup.
Figure 3 shows a schematic cross-sectional view of an electronic paper display device according to another embodiment of the present disclosure.
Fig. 4 shows a schematic cross-sectional view of an electronic paper display device according to another embodiment in which the protective layer, third and fourth electrodes of the present disclosure are disposed.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings may be exaggerated for clarity of description, and the elements denoted by the same reference numerals in the drawings are the same elements.

Electronic paper display device

1 shows a schematic cross-sectional view of an electronic paper display device 100 according to one embodiment of the present disclosure using microcapsules.

1, an electronic paper display 100 according to an embodiment of the present invention includes a lower piezoelectric substrate 110, a display element 130, and a second electrode 122 having a first electrode 121 formed thereon And an upper substrate 140 formed thereon.

A first electrode 121 is formed on the lower piezoelectric substrate 110.

The position of the first electrode 121 is not particularly limited and may be formed on one surface of the lower piezoelectric substrate 110 facing the display element 130 or may be formed on the lower piezoelectric substrate 110 have.

The lower piezoelectric substrate 110 may be formed using a transparent piezoelectric body.

The transparent piezoelectric material may be formed of at least one selected from the group consisting of polyvinylidene fluoride, an active fiber composite, or a piezoelectric fiber composite.

In the present disclosure

The first electrode 121 is made of a conductive material, and electrode materials conventionally used in the technical field of the present invention can be used.

For example, a conductive polymer such as polythiophene or polyaniline, metal particles such as silver or nickel, a polymer film containing the metal particles, and indium-tin-oxide (ITO) may be used.

A plurality of display elements 130 may be formed on the first electrode 121.

FIG. 1 shows an electronic paper display device using a microcapsule 130, and FIG. 2 shows an electronic paper display device using a microcup 130 '.

In the microcapsule, a dispersion and display particles having at least two or more colors are formed in the encapsulant. In the microcapsule, an encapsulating liquid and display particles having at least two or more colors are formed in the partition wall.

The encapsulant is a transparent material. Examples of the material for forming the encapsulant include polyurethane, polyurethane, polyurea polyurethane, urea-formaldehyde resin, melamine-formaldehyde resin, polyamide, polyester, polysulfonamide, Polycarbonate, polysulfinate, epoxy resin, acrylic acid ester, methacrylic acid ester, vinyl acetate, gelatin, and the like.

The dispersion liquid is filled in the sealing agent of the display element 130.

The dispersion liquid may be an aromatic hydrocarbon such as an alkylbenzene derivative such as benzene, toluene, xylene, ethylbenzene or dodecylbenzene, phenylcyclohexane, 1,1-ditertirethane, 1,2- Diallylalkane derivatives such as bis (3,4-dimethylphenylethane) (BDMF), alkyl naphthalene derivatives such as diisopropyl naphthalene, alkyl biphenyl derivatives such as isopropyl phenyl, isopropyl phenyl and ISO amyl biphenyl, Terphenyl derivatives such as dibenzyltoluene and the like, benzyl naphthalene derivatives, phenylene oxide derivative gyre-alkylene derivatives, allylene dane derivatives, polychlorinated biphenyl derivatives, naphthenic hydrocarbons, etc. . In addition, aliphatic hydrocarbons such as hexane, cyclohexane, kerosene, isobar and paraffinic hydrocarbons, halogenated compounds such as chloroform, trichlorethylene, tetrachlorethylene, trifluoroethylene, tetrafluoroethylene, dichloromethane, Phthalic acid esters such as dicyclohexyl phthalate, phthalic acid diacyl phthalate, dicyclohexyl phthalate, and the like, phosphoric acid esters such as oleic acid Butyl, diethylene glycol dibenzoate, dioctyl sebacate, dibutyl sebacate, trioctyl dioctyltrimethylolmellitate, acetyltriethyl citrate, dodecyl maleate, dibutyl maleate, ethyl acetate and the like Acid esters, chlorinated paraffin, and N, N-dibutyl-2-butoxy-5-tertiary octyl aniline.

The dispersion liquid is not limited to those described above, and the dispersion liquid may be used alone or in combination of two or more.

The display element 130 may contain white display particles and black display particles dispersed in a dispersion.

The display particles can be formed using inorganic or organic pigment particles.

Examples of the inorganic pigment particles include white pigments such as white pigments, zinc pigments, lithopone, titanium dioxide, zinc oxide, antimony oxide, calcium carbonate, kaolin, mica, barium sulfate, gloss white, alumina white, talc, silica, calcium silicate, cadmium red, White iron oxide, titanium yellow, titanium barium yellow, cadmium orange, cadmium ritofone orange, morbidate orange, red iron oxide, podium, scarlet red, cadmium red, cadmium ritofone red, amber, brown iron oxide, Cobalt blue, cobalt aluminum chromium blue, cobalt violet, minerals violet, carbon black, iron black, manganese ferrite black, cobalt chrome green, chromium oxide, pyridine, cobalt green, cobalt chrome green, titanium cobalt green, Cobalt ferrite black, copper chrome black, copper chromium manganese black, black low-dimensional titanium oxide (titanium black), aluminum It may be the flour, dongbun, ROCK, tin powder, zinc powder and the like.

Examples of the organic pigment particles include first yellow, disazo yellow, condensed azoiron, anthrapyrimidine yellow, ISO indoline yellow, copper azomethine yellow, quinophthaloin yellow, benzamidazolone yellow, Wherein the coloring agent is selected from the group consisting of yellow, monoazo yellow lake, dinitroaniline orange, pyrazolone orange, perinone orange, naphthol red, toluidine red, pamanendocarmin, brilliant first skarred, pyrazolone red, permanent red, lisorred, But are not limited to, lake red, brilliant carmine, naphthol red, quinacridone magenta condensate azoled, naphthocarmin, perylenescal red, condensed azoscarrad, benzimidazolonamine, anthraquinolyl red, perylene red, Maroon, quinacridone maroon, quinacridone scarlet, quinacridone red, diketopyrrolopyrrole red, benzamidazolone brown, phthaloic acid Nin green, you can use the Victoria blue lake, phthalocyanine blue, first skive base, alkaline Libreville tona, Dan Tron blue, methyl violet lake, dioxazine violet, violet-naphthol and the like.

The second electrode 122 may be disposed on the display element 130.

The second electrode 122 may be formed on the upper substrate 140 and disposed on the upper side of the display device 130.

The second electrode 122 may be formed of the same material as the first electrode 121.

Since the upper substrate 140 can be provided as a display surface, it is preferable that the upper substrate 140 is made of a transparent material.

In the present disclosure, the light transmittance of the transparent material can be determined within a range that does not deteriorate the visibility, and for example, it can be formed of a material having a light transmittance of 85% or more.

The upper substrate 140 may be made of glass or a flexible plastic type. The plastics include, but are not limited to, polyethylene terephthalate (PET), polycarbonate (PC), or polymethylmethacrylate (PMMA), polyethylene naphthalate (PEN), polyethersulfone (PES) (COC), polydimethylsiloxane (PDMS), polyurethane acrylate (PUA), or the like can be used.

The display particles included in the display element 130 are very small in size and aggregation occurs.

In order to solve this aggregation phenomenon, an AC voltage is applied together with a DC voltage at the initial stage when the electronic paper display device is driven. However, there is a problem that the agglomeration phenomenon of the display particles can not be completely solved only by the application of the AC voltage.

Since the electronic paper display device according to the embodiment of the present disclosure generates physical vibration in the lower piezoelectric substrate 110, aggregation of display particles can be quickly and completely solved.

Accordingly, the electronic paper display device according to an embodiment of the present disclosure can drive at a lower voltage than conventional electronic paper display devices, and can prevent the display particles from aggregating, thereby improving the contrast ratio.

A third electrode 123 may be formed on the lower portion of the lower piezoelectric substrate 110.

The third electrode 123 is electrically connected to the second electrode 122. When the AC voltage is applied at the initial stage of driving the electronic paper display device, the AC voltage is simultaneously applied to the piezoelectric body, Can be induced to occur simultaneously.

Fig. 3 shows a schematic cross-sectional view of an electronic paper display device 200 according to another embodiment of the present disclosure.

3, differences from the electronic paper display device 100 of Figs. 1 and 2 will be described below.

Referring to FIG. 3, unlike the upper substrate 140 of FIG. 1, the upper piezoelectric substrate 240 may be disposed on a rolled paper display device according to another embodiment of the present disclosure.

The upper piezoelectric substrate 240 may be formed of a transparent piezoelectric body.

Since the upper piezoelectric substrate 240 can be provided as a display surface, it is preferable that the upper piezoelectric substrate 240 is made of a transparent material.

The upper piezoelectric substrate 240 may be formed using a transparent piezoelectric body.

The transparent piezoelectric material may be formed of at least one selected from the group consisting of polyvinylidene fluoride, an active fiber composite, or a piezoelectric fiber composite.

In the present disclosure, the light transmittance of the transparent piezoelectric material can be determined within a range that does not deteriorate the visibility, and can be formed of, for example, a material having a light transmittance of 85% or more.

By forming the upper substrate with the upper piezoelectric substrate 240, aggregation of display particles can be eliminated more quickly, and thus the contrast ratio of the electronic paper display device can be improved.

Fig. 4 shows a schematic cross-sectional view of an electronic paper display device 200 according to another embodiment in which the protective layer and the electrode for a piezoelectric body of the present disclosure are disposed.

4, a third electrode 223 may be formed on a lower portion of the lower piezoelectric substrate 210, and a fourth electrode 224 may be formed on an upper portion of the upper piezoelectric substrate 240. Referring to FIG.

The third and fourth electrodes 223 and 224 may be formed of the same transparent electrode material as the first and second electrodes 221 and 222.

The third electrode 223 is electrically connected to the second electrode 222 and the fourth electrode 224 is electrically connected to the first electrode 221 to electrically connect the lower piezoelectric substrate 210 and the upper piezoelectric substrate 240 can induce a piezoelectric phenomenon.

That is, when the AC voltage is applied to the display element 240 at the initial stage of driving the electronic paper display device, the piezoelectric phenomenon can be simultaneously induced in the lower piezoelectric substrate 210 and the upper piezoelectric substrate 240.

Accordingly, the agglomeration of the display particles due to the AC voltage can be solved more quickly by the physical vibrations of the piezoelectric substrates 210 and 240.

A protective layer 250 may be formed on the fourth electrode 224 or the upper piezoelectric substrate 240.

When the upper piezoelectric substrate 240 is provided on the display surface, the protection layer 250 may be formed to prevent damage due to impact and damage due to the contamination, and the protection layer 250 may be formed of a transparent material .

Although the present disclosure has been mainly described with reference to a method using microcapsules and microcups in an electronic paper display device, it is also possible to substitute, modify and change the electronic paper display device using a twist ball method or the like.

The present disclosure is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited by the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

100: Electronic paper display device
110: Lower piezoelectric substrate
121: first electrode
122: second electrode
123: third electrode
130: display element
140: upper substrate

Claims (10)

A lower piezoelectric substrate on which a first electrode is disposed on an upper surface;
A plurality of display elements disposed on the lower piezoelectric substrate; And
And a second electrode disposed on the display element.
The method according to claim 1,
Wherein the display element is a microcapsule or a microcup.
The method according to claim 1,
Wherein the lower piezoelectric substrate is formed of a transparent piezoelectric material.
The method of claim 3,
Wherein the transparent piezoelectric material is formed of at least one selected from the group consisting of polyvinylidene fluoride, an active fiber composite material, and a piezoelectric fiber composite material.
The method according to claim 1,
And a third electrode formed on the lower surface of the lower piezoelectric substrate.
The method according to claim 1,
And an upper piezoelectric substrate disposed above the second electrode.
The method according to claim 6,
Wherein the upper piezoelectric substrate is formed of a transparent piezoelectric material.
8. The method of claim 7,
Wherein the transparent piezoelectric material is formed of at least one selected from the group consisting of polyvinylidene fluoride, an active fiber composite material, and a piezoelectric fiber composite material.
The method according to claim 6,
And a third electrode disposed on the upper piezoelectric substrate.
10. The method of claim 9,
And a protective layer disposed on the third electrode.

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