JP4688451B2 - Driving method of image display panel - Google Patents

Description

  The present invention relates to a reversible image display panel capable of suitably displaying a barcode.

  Conventionally, barcodes have been produced by printing. Then, print the barcode directly on the tare of the product, attach the printed label to the tare of the product, attach the barcode to the product, and read the barcode with a barcode reader etc. Was configured to know. However, since the barcode display once pasted on the product cannot be rewritten, the entire label printed with the barcode had to be remade. Moreover, since the barcode label which became unnecessary is discarded, it was a waste of resources.

On the other hand, as a method for solving the above-described problem, a reversible image display method using a liquid crystal or a thermal dye has been recently considered (for example, Patent Document 1). However, the image display method using a liquid crystal or a thermal dye has a problem that the image is not clear and a reading error occurs when a bar code is displayed.
JP 2003-222893 A

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems and to provide an image display panel and a driving method thereof capable of performing a clear image display that does not cause a reading error when a bar code is displayed.

According to the driving method of the image display panel of the present invention, an image display medium is sealed between two opposing substrates, at least one of which is transparent, an electric field is applied to the image display medium, and the image display medium is moved to move the image. A reversible image display panel for displaying a one-dimensional barcode, wherein a row electrode composed of a plurality of electrodes extending in a row direction on one substrate and the other In performing one-dimensional bar code display by applying a voltage to a matrix electrode composed of a plurality of electrodes extending in the column direction on the substrate, without scanning the row electrodes from one end to the other, One-dimensional bar code display is performed at a time by applying a driving voltage to the column electrode to be displayed in a one-dimensional bar code while a voltage of 0 V is applied to all the row electrodes. .

As a preferred example of the driving method of the image display panel according to the present invention, the driving method is switched to the driving method according to claim 1 only during the one-dimensional bar code display. Driving method.

  In the image display panel of the present invention, an image display medium is sealed between two opposing substrates, at least one of which is transparent, an electric field is applied to the image display medium, and the image display medium is moved to display an image. By displaying the barcode on the reversible image display panel, it is possible to perform a clear image display in which no reading error occurs when the barcode is displayed.

  In the image display panel driving method of the present invention, a row electrode including a plurality of electrodes extending in the row direction on one substrate and a column electrode including a plurality of electrodes extending in the column direction on the other substrate are provided. When displaying a barcode by applying a voltage to the matrix electrode composed of the above, by applying a driving voltage to the column electrode to be barcode-displayed without scanning the row electrode from one end to the other, By performing bar code display, the maximum contrast of the panel can be drawn and the bar code readability can be improved.

  First, a basic configuration of an image display panel that is an object of the present invention will be described. In the image display panel used in the present invention, an electric field is applied to two types of image display media (particle group or powder fluid) sealed between two opposing substrates and having different charging characteristics. Along the applied electric field direction, the image display medium charged at a low potential toward the high potential side is attracted by the force of the electric field or Coulomb force, and charged at a high potential toward the low potential side. The image display medium is attracted by an electric field force, a Coulomb force, or the like, and the image display medium is reciprocated by a change in the electric field direction due to the potential switching, thereby displaying an image. Therefore, it is necessary to design the image display panel so that the image display medium moves uniformly and can maintain stability during repetition or storage. Here, the force applied to the particles or powder fluid used as the image display medium is not only the force attracted by the Coulomb force between the particles or powder fluid, but also the image power, intermolecular force, liquid crosslinking force with the electrode or substrate. , Gravity and so on.

An example of the image display panel of the present invention will be described with reference to FIGS. 1 (a) and (b) to FIGS. 3 (a) and 3 (b).
In the example shown in FIGS. 1A and 1B, an electric field applied from the outside of the substrates 1 and 2 to an image display medium 3 having two or more different colors (here, white particles 3W and black particles 3B are shown). Accordingly, the black particles 3B are moved vertically to the substrates 1 and 2 so that the observer can visually recognize the black particles 3B, or the white particles 3W are visually recognized by the observer. . In the example shown in FIG. 1B, in addition to the example shown in FIG. 1A, partition walls 4 are provided, for example, in a lattice shape between the substrates 1 and 2 to define display cells.
In the example shown in FIGS. 2A and 2B, an electrode 5 and a substrate 2 provided on a substrate 1 with an image display medium 3 of two or more different colors (here, white particles 3W and black particles 3B are shown). In accordance with the electric field generated by applying a voltage between the electrode 6 and the electrode 6 provided on the substrate, the substrate is moved perpendicularly to the substrates 1 and 2, and the black particles 3B are visually recognized by the observer, or black display is performed. The white particles 3W are visually recognized by an observer to display white. In the example shown in FIG. 2B, in addition to the example shown in FIG. 2A, partition walls 4 are provided, for example, in a lattice form between the substrates 1 and 2 to define display cells.
The above description can be similarly applied to the case where the white particles 3W are replaced with the white powder fluid and the black particles 3B are replaced with the black powder fluid.
FIGS. 3A and 3B show an example of a microcapsule electrophoretic display panel which is different from FIGS. 1A and 1B and FIGS. 2A and 2B. This example is also an object of the image display panel of the present invention. In the example shown in FIGS. 3A and 3B, two or more kinds of image display media 3 having different colors (here, the white particles 3W and the black particles 3B) are filled in the microcapsules and then between the substrates 1 and 2. The black particles 3B are moved vertically to the substrates 1 and 2 according to the applied electric field, and the black particles 3B are visually recognized by the observer to display black, or the white particles 3W are visually recognized by the observer. White display. In the example shown in FIG. 3B, in addition to the example shown in FIG. 3A, a partition 4 is provided between the substrates 1 and 2 to form a display cell, for example.

  The image display panel according to the present invention is characterized in that a bar code is displayed on the reversible image display panel having the above-described configuration. Next, the barcode that is the display target of the present invention will be described.

  FIG. 4 is a diagram for explaining an example of a barcode. As shown in FIG. 4, the barcode is composed of a quiet zone, a barcode symbol, and a quiet zone in the length direction, and the barcode symbol is composed of a stator character, data (message), check digit, and stop character. FIG. 5 is a diagram for explaining the bars and spaces constituting the barcode. The bar code constituting each part shown in FIG. 4 is composed of a combination of a thin / thick bar (NB, WB) and a thin / thick space (NS, WS) which are the smallest units. In the present invention, the ratio is NB: WB = NS: WS = 1 dot: 2 dots. FIG. 6 is a diagram for explaining an example of a QR code that is a two-dimensional barcode. Bar codes can only have data in one direction, whereas QR codes can have information in the horizontal and vertical directions, so QR codes are several tens to several hundred times larger than bar codes. Have data.

  Here, when a barcode or a QR code, which is a two-dimensional barcode, is displayed in black and white display using a reflective liquid crystal panel (LCD), the black and white contrast is not sufficient, and the scanned and displayed are Interference may occur and the viewing angle is narrow, so reading errors increase.

  On the other hand, in the present invention, an image display medium is sealed between two opposing substrates at least one of which is transparent, an electric field is applied to the image display medium, and the image display medium is moved to display an image. In an image display panel of the nature, first, particles or powder fluid is used as an image display medium, so that a black-and-white contrast is originally large and a viewing angle is widened. Further, an electric field is applied only when the image display medium is moved, and even after the movement, even if no electric field is applied, the image display medium stays at the moved position, so that the display image is held (there is a memory property). Therefore, interference due to scan display does not occur. Furthermore, when the electric field is applied again when it is desired to rewrite the image, the image display medium is moved again to display another image, so that the image can be rewritten reversibly. Furthermore, since the image display medium directly displays an image, the size of the image display medium determines the sharpness of the image. In the present invention, a group of particles having a particle diameter of 1 to 20 μm or the like is used as an image display medium, so that a clear image can be displayed, and a delicate and precise image display such as a barcode can also be performed. Therefore, when a barcode or a QR code that is a two-dimensional barcode is displayed on the image display panel of the present invention, the reading accuracy can be significantly improved as compared with the case where a conventional liquid crystal or thermal dye is used. it can.

  Next, a method for driving the image display panel of the present invention will be described. The driving method described below is a matrix composed of a row electrode composed of a plurality of electrodes extending in the row direction on one substrate and a column electrode composed of a plurality of electrodes extending in the column direction on the other substrate. The present invention is limited to the case where bar code display is performed by applying a voltage to the electrode, and cannot be applied to display of a QR code.

  FIG. 7 is a diagram for explaining an example of the matrix electrode used in the image display panel driving method of the present invention. In the example shown in FIG. 7, row electrodes 5-1 to 5-4 made up of a plurality (four in this case) of electrodes extending in the row direction on one substrate 1 and extending in the column direction on the other substrate 2. A matrix electrode is constituted by the column electrodes 6-1 to 6-5 including a plurality of (here, five) electrodes. The driving method of scanning and applying voltages to the matrix electrodes in order of the row electrodes 5-1 to 5-4 is generally used for the image display panel of the present invention having the above-described configuration.

  FIGS. 8A to 8D are diagrams showing an example of a normal driving method using the matrix electrode shown in FIG. In the example shown in FIGS. 8A to 8D, in the display cell at the intersection of the row electrodes 5-1 to 5-4 and the column electrodes 6-1 to 6-5, + V (or -V) is provided between both electrodes. The display cell is inverted by applying a voltage of + V / 2 (or -V / 2) that is not inverted to any of the other display cells, and the display state of the display cell is maintained. . In this example, it is assumed that the positions of the column electrodes 6-2 and 6-4 are displayed in black to perform bar code display. Therefore, in the example shown in FIGS. 8A to 8D, when the voltage is applied by sequentially scanning the row electrodes 5-1 to 5-4, the drive voltages are always applied to the column electrodes 6-2 and 6-4. V is applied.

  In the normal driving method using the matrix electrode described above, first, as shown in FIG. 8A, the voltage 0 is applied to the row electrode 5-1 of the first row, and the other row electrodes 5-2. A bar code is displayed on the first row by applying a voltage V / 2 to 5-4. Next, as shown in FIG. 8B, the voltage 0 is applied to the row electrode 5-2 of the second row, and the voltage V / 2 is applied to the other row electrodes 5-1, 5-3, and 5-4. Is applied to display the bar code in the second row. Next, as shown in FIG. 8C, the voltage 0 is applied to the third row electrode 5-3, and the voltage V / 2 is applied to the other row electrodes 5-1, 5-2, and 5-4. Is applied to display the bar code in the third row. Next, as shown in FIG. 8D, the voltage 0 is applied to the fourth row electrode 5-4, and the voltage V / 2 is applied to the other row electrodes 5-1 to 5-3. As a result, the bar code on the fourth line is displayed. One bar code display is thus completed.

In this normal driving method, the column electrode 6-- of the second row in FIG. 8B, the first and second rows in FIG. 8C, and the first to third rows in FIG. In the display cells intersecting with 2 and 6-4, there is a case where a display cell to be displayed in black becomes whitish gray when V / 2 is applied and a crosstalk is reduced, and the maximum contrast may not be obtained.
The driving method of the present invention that can solve this problem will be described below.

  FIG. 9 is a diagram showing an example of the driving method of the present invention using the matrix electrode shown in FIG. In the example shown in FIG. 9, the bar code display is performed with the voltage 0 applied to all the row electrodes 5-1 to 5-4 without scanning the row electrodes 5-1 to 5-4 from one end to the other end. By applying a driving voltage to the column electrodes 6-2 and 6-4 to be displayed, barcode display is performed at a time. Therefore, in the example shown in FIG. 9, since scanning is not performed for bar code display, the influence of crosstalk does not appear and the maximum contrast can be obtained. This example is effective only for bar code display and cannot perform normal display. Therefore, in the case of an image display panel that also uses displays other than barcode display, the driving method shown in FIG. 9 is used only during barcode display, and FIGS. 8A to 8D are used during other normal displays. It is preferable to switch the driving method according to the display method so that the driving method shown in FIG.

  Hereafter, each member which comprises the image display panel of this invention is demonstrated.

  As for the substrate, at least one of the substrates is a transparent substrate 2 on which the color of the image display medium can be confirmed from the outside of the panel, and a material having high visible light transmittance and good heat resistance is preferable. The substrate 1 may be transparent or opaque. Examples of substrate materials include polymer sheets such as polyethylene terephthalate, polyethersulfone, polyethylene, polycarbonate, polyimide, and acrylic, flexible materials such as metal sheets, and flexible materials such as glass and quartz. There are no inorganic sheets. The thickness of the substrate is preferably from 2 to 5000 μm, more preferably from 5 to 2000 μm. If it is too thin, it will be difficult to maintain the strength and the spacing uniformity between the substrates, and if it is thicker than 5000 μm, a thin image display panel is obtained. Inconvenient in case.

  Electrode forming materials for electrodes provided as necessary include metals such as aluminum, silver, nickel, copper, and gold, conductive metal oxides such as ITO, indium oxide, conductive tin oxide, and conductive zinc oxide, polyaniline , Conductive polymers such as polypyrrole and polythiophene are exemplified, and are appropriately selected and used. As a method for forming an electrode, a method of forming the above-described materials into a thin film by sputtering, vacuum deposition, CVD (chemical vapor deposition), coating, or the like, or mixing a conductive agent with a solvent or a synthetic resin binder. The method of apply | coating is used. The electrode provided on the viewing side substrate needs to be transparent, but the electrode provided on the back side substrate does not need to be transparent. In any case, the above-mentioned material that is conductive and capable of pattern formation can be suitably used. Note that the electrode thickness is not particularly limited as long as the conductivity can be secured and the light transmittance is not hindered, and is preferably 3 to 1000 nm, preferably 5 to 400 nm. The material and thickness of the electrode provided on the back side substrate are the same as those of the electrode provided on the view side substrate described above, but need not be transparent. In this case, the external voltage input may be superimposed with direct current or alternating current.

  The shape of the partition 4 provided as needed is optimally set according to the type of image display medium involved in the display, and is not limited in general. However, the width of the partition is 2 to 100 μm, preferably 3 to 50 μm. Is adjusted to 10 to 500 μm, preferably 10 to 200 μm. In forming the partition walls, a both-rib method in which ribs are formed on each of the opposing substrates and then bonded, and a one-rib method in which ribs are formed only on one substrate are conceivable. In the present invention, any method is preferably used.

  As shown in FIG. 10, the display cells formed by the partition walls made of these ribs are exemplified by a square shape, a triangular shape, a line shape, a circular shape, and a hexagonal shape as viewed from the substrate plane direction. The shape and the mesh shape are exemplified. It is better to make the portion corresponding to the cross section of the partition wall visible from the display side (the area of the frame portion of the display cell) as small as possible, and the sharpness of the image display increases. Examples of the method for forming the partition include a mold transfer method, a screen printing method, a sand blast method, a photolithography method, and an additive method. Among these, a photolithography method using a resist film and a mold transfer method are preferably used. In any method, the present invention can be suitably used.

  Next, the powder fluid as an image display medium used in the image display panel of the present invention will be described. As for the name of the powder fluid as the image display medium of the present invention, the present applicant has obtained the right of “Electronic Powder Fluid (registered trademark)”.

  The “powder fluid” in the present invention is a substance in an intermediate state of both fluid and particle characteristics that exhibits fluidity by itself without borrowing the force of gas or liquid. For example, liquid crystal is defined as an intermediate phase between a liquid and a solid, and has fluidity that is a characteristic of liquid and anisotropy (optical properties) that is a characteristic of solid (Heibonsha: Encyclopedia) . On the other hand, the definition of particle is an object with a finite mass even if it is negligible, and is said to be affected by gravity (Maruzen: Physics Encyclopedia). Here, even in the case of particles, there are special states of gas-solid fluidized bed and liquid-solid fluids. When gas is flowed from the bottom plate to the particles, upward force is applied to the particles according to the velocity of the gas. Is a gas-solid fluidized bed that is in a state where it can easily flow when it balances with gravity, and it is also called a liquid-solid fluidized state that is fluidized by a fluid (ordinary) Company: Encyclopedia). As described above, the gas-solid fluidized bed body and the liquid-solid fluid are in a state of using a gas or liquid flow. In the present invention, it has been found that a substance in a state of fluidity can be produced specifically without borrowing the force of such gas and liquid, and this is defined as powder fluid.

  That is, the pulverulent fluid in the present invention is in an intermediate state having both the characteristics of particles and liquid, as in the definition of liquid crystal (liquid and solid intermediate phase), and is the characteristic of the above-mentioned particles. It is a substance that is extremely unaffected and exhibits a unique state with high fluidity. Such a substance can be obtained in an aerosol state, that is, a dispersion system in which a solid or liquid substance is stably suspended as a dispersoid in a gas, and the solid substance is used as a dispersoid in the image display device of the present invention. Is.

The image display panel of the present invention is a powder fluid exhibiting high fluidity in an aerosol state in which solid particles are stably suspended as a dispersoid, for example, as an image display medium between two opposing substrates, at least one of which is transparent. Such a powder fluid can be easily and stably moved by a Coulomb force by applying a low voltage.
As described above, for example, the powder fluid used in the present invention is a substance in an intermediate state between fluid and particles, which exhibits fluidity by itself without borrowing the force of gas or liquid. This powder fluid can be in an aerosol state in particular, and in the image display device of the present invention, a solid substance is used in a state of relatively stably floating as a dispersoid in the gas.

  Next, the particles as the image display medium used in the image display panel of the present invention will be described. The particles can contain a charge control agent, a colorant, an inorganic additive, and the like, if necessary, in the resin as the main component, as in the conventional case. Examples of resins, charge control agents, colorants, and other additives will be given below.

  Examples of the resin include urethane resin, urea resin, acrylic resin, polyester resin, acrylic urethane resin, acrylic urethane silicone resin, acrylic urethane fluororesin, acrylic fluororesin, silicone resin, acrylic silicone resin, epoxy resin, polystyrene resin, styrene Acrylic resin, polyolefin resin, butyral resin, vinylidene chloride resin, melamine resin, phenol resin, fluororesin, polycarbonate resin, polysulfone resin, polyether resin, polyamide resin and the like can be mentioned, and two or more kinds can be mixed. In particular, acrylic urethane resin, acrylic silicone resin, acrylic fluororesin, acrylic urethane silicone resin, acrylic urethane fluororesin, fluororesin, and silicone resin are suitable from the viewpoint of controlling the adhesive force with the substrate.

  The charge control agent is not particularly limited. Examples of the negative charge control agent include salicylic acid metal complexes, metal-containing azo dyes, metal-containing oil-soluble dyes (including metal ions and metal atoms), and quaternary ammonium salt systems. Examples thereof include compounds, calixarene compounds, boron-containing compounds (benzyl acid boron complexes), and nitroimidazole derivatives. Examples of the positive charge control agent include nigrosine dyes, triphenylmethane compounds, quaternary ammonium salt compounds, polyamine resins, imidazole derivatives, and the like. In addition, metal oxides such as ultrafine silica, ultrafine titanium oxide, ultrafine alumina, nitrogen-containing cyclic compounds such as pyridine and derivatives and salts thereof, various organic pigments, resins containing fluorine, chlorine, nitrogen, etc. are also charged. It can also be used as a control agent.

  As the colorant, various organic or inorganic pigments and dyes as exemplified below can be used.

Examples of the black colorant include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon and the like.
Examples of blue colorants include C.I. I. Pigment blue 15: 3, C.I. I. Pigment Blue 15, Bituminous Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Metal-free Phthalocyanine Blue, Phthalocyanine Blue Partial Chlorides, Fast Sky Blue, Indanthrene Blue BC and the like.
Examples of red colorants include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, resol red, pyrazolone red, watching red, calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment Red 2 etc.

As yellow colorants, yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral first yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, C.I. I. Pigment Yellow 12 etc.
Examples of green colorants include chrome green, chromium oxide, pigment green B, C.I. I. Pigment Green 7, Malachite Green Lake, Final Yellow Green G, etc.
Examples of the orange colorant include red chrome yellow, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK, C.I. I. Pigment Orange 31 etc.
Examples of purple colorants include manganese purple, first violet B, and methyl violet lake.
Examples of white colorants include zinc white, titanium oxide, antimony white, and zinc sulfide.

  Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white. Examples of various dyes such as basic, acidic, disperse, and direct dyes include nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

Examples of inorganic additives include titanium oxide, zinc white, zinc sulfide, antimony oxide, calcium carbonate, lead white, talc, silica, calcium silicate, alumina white, cadmium yellow, cadmium red, cadmium orange, titanium yellow, Examples include bitumen, ultramarine blue, cobalt blue, cobalt green, cobalt violet, iron oxide, carbon black, manganese ferrite black, cobalt ferrite black, copper powder, and aluminum powder.
These pigments and inorganic additives can be used alone or in combination. Of these, carbon black is particularly preferable as the black pigment, and titanium oxide is preferable as the white pigment.

  The particles used in the image display panel of the present invention have an average particle diameter d (0.5) in the range of 0.1 to 50 μm, and are preferably uniform and uniform. If the average particle diameter d (0.5) is larger than this range, the display is not clear, and if it is smaller than this range, the cohesive force between the particles becomes too large, which hinders the movement of the particles.

Furthermore, in the present invention, regarding the particle size distribution of each particle, the particle size distribution Span represented by the following formula is less than 5, preferably less than 3.
Span = (d (0.9) −d (0.1)) / d (0.5)
(However, d (0.5) is a numerical value expressing the particle diameter in μm that 50% of the particles are larger than this and 50% is smaller than this, and d (0.1) is a particle in which the ratio of the smaller particles is 10%. (Numerical value expressed in μm, and d (0.9) is a numerical value expressed in μm for a particle diameter of 90% or less.)
By keeping Span within a range of 5 or less, the size of each particle is uniform, and uniform particle movement becomes possible.

  Furthermore, regarding the correlation between the particles, the ratio of d (0.5) of the particles having the minimum diameter to d (0.5) of the particles having the maximum diameter among the used particles is set to 50 or less, preferably 10 or less. It is essential.

The particle size distribution and the particle size can be obtained from a laser diffraction / scattering method or the like. When laser light is irradiated onto particles to be measured, a light intensity distribution pattern of diffracted / scattered light is spatially generated, and this light intensity pattern has a corresponding relationship with the particle diameter, so that the particle diameter and particle diameter distribution can be measured. .
Here, the particle size and particle size distribution in the present invention are obtained from a volume-based distribution. Specifically, using a Mastersizer2000 (Malvern Instruments Ltd.) measuring instrument, particles are introduced into a nitrogen stream, and the attached analysis software (software based on volume-based distribution using Mie theory) The diameter and particle size distribution can be measured.

  The charge amount of the image display medium naturally depends on the measurement conditions, but the charge amount of the image display medium in the image display panel is almost the initial charge amount, the contact with the partition wall, the contact with the substrate, and the charge decay with the elapsed time. In particular, it was found that the saturation value of the charging behavior of the image display medium is the dominant factor.

Furthermore, in the present invention, when a dry image display medium is used, it is important to manage the gas in the gap surrounding the image display medium between the substrates, which contributes to improved display stability. Specifically, it is important that the relative humidity at 25 ° C. is 60% RH or less, preferably 50% RH or less, more preferably 35% RH or less with respect to the humidity of the gas in the gap.
1A, 1B, 3A, and 3B, the gap portion is defined by the electrodes 5 and 6 and the image display medium (particles) from the portion sandwiched between the opposing substrate 1 and substrate 2. It refers to the gas portion in contact with the so-called image display medium, excluding the group or powdered fluid 3) occupied portion, the partition 4 occupied portion (if present), and the device seal portion.
The gas in the gap is not limited as long as it is in the humidity region described above, but dry air, dry nitrogen, dry argon, dry helium, dry carbon dioxide, dry methane, and the like are preferable. This gas needs to be sealed in the apparatus so that the humidity is maintained. For example, the image display medium is filled and the substrate is assembled in a predetermined humidity environment. It is important to apply a sealing material and a sealing method to prevent the above.

The distance between the substrates in the image display panel of the present invention is not limited as long as the image display medium can be moved and the contrast can be maintained, but is usually adjusted to 10 to 500 μm, preferably 10 to 200 μm.
The volume occupation ratio of the image display medium in the space between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%. If it exceeds 70%, the movement of the image display medium is hindered. If it is less than 5%, the contrast tends to be unclear.

  In the image display panel of the present invention, an image display medium is sealed between two opposing substrates, at least one of which is transparent, an electric field is applied to the image display medium, and the image display medium is moved to display an image. Since it is configured as a reversible image display panel, it can be suitably used to display a barcode or a QR code that is a two-dimensional barcode. Further, in the method for manufacturing an image display panel according to the present invention, it is possible to display a bar code at a time by applying a driving voltage to a column electrode to display a bar code without scanning the row electrode from one end to the other end. By doing so, the maximum contrast of the panel can be extracted and the barcode readability can be improved.

(A), (b) is a figure which shows an example of the image display panel of this invention, respectively. (A), (b) is a figure which shows the other example of the image display panel of this invention, respectively. (A), (b) is a figure which shows an example of the image display apparatus of a microcapsule electrophoresis type | mold as another example of the image display panel of this invention, respectively. It is a figure for demonstrating an example of a barcode. It is a figure for demonstrating the bar and space which comprise a barcode. It is a figure for demonstrating an example of QR code which is a two-dimensional barcode. It is a figure for demonstrating an example of the matrix electrode used with the drive method of the image display panel of this invention. (A)-(d) is a figure which shows an example of the normal drive method using the matrix electrode shown in FIG. 7, respectively. It is a figure which shows an example of the drive method of this invention using the matrix electrode shown in FIG. It is a figure which shows an example of the shape of the partition in the image display panel of this invention.

Explanation of symbols

1, 2 Substrate 3 Image display medium (particle or powder fluid)
3W white particles (white powder fluid)
3B Black particles (black powder fluid)
4 Partitions 5 and 6 Electrodes 5-1 to 5-4 Row electrodes 6-1 to 6-4 Column electrodes

Claims (2)

This is a reversible image display panel in which an image display medium is sealed between two opposing substrates, at least one of which is transparent, an electric field is applied to the image display medium, and the image display medium is moved to display an image. In the method for driving an image display panel for displaying a one-dimensional barcode, a row electrode composed of a plurality of electrodes extending in the row direction on one substrate and a plurality of electrodes extending in the column direction on the other substrate When applying a voltage to a matrix electrode composed of column electrodes and performing one-dimensional bar code display, a voltage of 0 V is applied to all the row electrodes without scanning the row electrodes from one end to the other end. A method for driving an image display panel, wherein one-dimensional barcode display is performed at a time by applying a drive voltage to a column electrode to be displayed in one-dimensional barcode. A driving method for an image display panel, wherein the driving method is switched to the driving method according to claim 1 only when displaying a one-dimensional barcode.

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