JP2006234911A - Reversible bar code display plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bar code display plate using a reversible information display panel for effectively suppressing consumption of resources by enabling clear bar code display without generating reading errors while sufficiently suppressing a manufacture cost and man-hours. <P>SOLUTION: The bar code display plate 1 seals a display medium in an enclosed space between two transparent boards facing each other, at least either of which is transparent, moves the display medium in an electric field formed between the boards, and has a display unit comprising a reversible information display panel displaying necessary information on a transparent board side. Electrification characteristics are different, two kinds of the white and black display media composed of two kinds of white and black display medium particles in which an average particle diameter is in a range of 3-10 μm are used, and the total thickness of the information display panel is ≥10 μm to <1 mm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a bar code display board having a display unit comprising a reversible information display panel, which can be rewritten and reused any number of times, and does not require a rewrite driver to be installed. It is about a board.

  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, there has been a reversible information display panel using liquid crystal or a thermal dye as an information display panel capable of repeatedly displaying information such as images.

However, if a conventional information display panel using liquid crystal or thermal dye is used for bar code display, there is a problem such as reading error when displayed as a bar code because it cannot display clear information. It could not be used for the barcode display board which is the subject of the present invention.
On the other hand, the present applicant encloses display media in a space between two substrates, at least one of which is transparent, and moves the display media in an electric field to display required information on the transparent substrate side. A reversible information display panel is proposed (for example, see Patent Document 1). This information display panel moves the display medium based on the formation of an electric field between the substrates, the Coulomb force between the particles for the display medium constituting the display medium, the electric image force with the electrode, the intermolecular force, the liquid crosslinking force. Even when the electric field between the substrates is lost due to gravity or the like, the display information can be maintained over a long period of time, and thus it has the advantage of exhibiting excellent display storage stability. Therefore, after displaying required information such as figures, symbols, images, etc. on the transparent substrate for a long period of time, it can be easily erased and rewritten, and can be used repeatedly. There is sex.

JP 2004-341123 A

  The object of the present invention is to provide a clear bar code that eliminates the above-mentioned problems and does not cause a reading error while keeping production costs and man-hours sufficiently low, and is capable of effectively suppressing resource consumption. An attempt is made to provide a bar code display panel.

  The reversible bar code display panel of the present invention is an electric field in which a display medium is enclosed in a sealed space between two substrates facing each other and at least one of which is transparent, and the display medium is formed between the substrates. A bar code display plate having a display unit composed of a reversible information display panel that is moved to display necessary information on the transparent substrate side, has different charging characteristics, and has an average particle diameter of 3 to 10 μm. In this case, two types of black and white display media each composed of two types of black and white particles for display media are used, and the total thickness of the information display panel serving as a display unit is 10 μm or more and less than 1 mm.

  As a preferred example of the reversible barcode display panel of the present invention, the display medium enclosed between the substrates is mainly composed of insulating particles and does not include magnetic particles, and at least one of the two substrates. The thickness is 0.4 mm or less, and the distance between the substrates created by the two substrates facing each other is 0.1 mm or less, each substrate is made of a plastic material, and the display medium As a particle group composed of particles for display medium or a powder fluid composed of particles for display medium.

  In the reversible bar code display board using the reversible information display panel of the present invention, first, when the information is displayed as a bar code because it cannot display clear information that the conventional information display panel has, a reading error occurs. The total thickness of the information display panel using two types of black and white display media composed of particles for two types of black and white display media having different charging characteristics and an average particle diameter in the range of 3 to 10 μm. This is solved by setting the thickness to 10 μm or more and less than 1 mm. Thus, display information can be rewritten reliably by using charge forming means that can form charges on the information display panel substrate (for example, means for forming charges as an electrostatic latent image by a photoconductor or means for forming charges by ion flow). Can be done. Therefore, in a reversible bar code display board using a reversible information display panel having the above-described configuration, clear information can be displayed, and once displayed information is securely erased, new information is displayed. Can be performed any number of times, so that it is not necessary to perform predetermined printing or the like on the paper, so that the cost and the man-hours for the same can be greatly suppressed and the consumption of resources can be sufficiently prevented.

  Further, in the reversible bar code display board of the present invention, making each substrate made of a plastic material not only makes the panel sufficiently thin and light, but also makes it possible to display the bar code display of the present invention. This is also an effective method for surely erasing necessary bar code information and then displaying new bar code information clearly.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 and FIGS. 3 (a) and 3 (b) are diagrams showing one embodiment and another embodiment of a bar code display board according to the present invention, respectively. In FIG. 3 is a barcode display board configured as an original barcode, and reference numeral 2 in FIGS. 3A and 3B denotes a QR code in which the barcode of the present invention is configured as a two-dimensional barcode. FIG. 3B shows the QR code together with a substrate which is a bar code display unit. In the illustrated example, a display unit of 160 × 160 pixels is formed on the substrate. The bar code 1 and the QR code 2 are configured as a square bar code display plate composed of a reversible information display panel, which will be described later, and by providing an adhesive layer made of, for example, a slightly adhesive adhesive on the back surface thereof. It is configured to be detachable with respect to a product tare or the like that is an object to be used.

A barcode display board 1 shown in FIG. 1 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. 2 is a diagram for explaining the bars and spaces constituting the barcode. 1 is composed of a combination of thin and thick bars (NB, WB) and thin and thick spaces (NS, WS) which are the smallest units. In the present invention, the ratio is NB: WB = NS: WS = 1 dot: 2 dots to 1 dot: 3 dots.
In the barcode display board 1 shown in FIG. 1, the barcode can only have data in one direction, whereas in the QR code 2 shown in FIGS. 3 (a) and 3 (b), the barcode is displayed in the horizontal and vertical directions. Since the information can be provided, the QR code 2 has data several tens to several hundred times that of the barcode 1.

  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. In the case of using an LCD, since there is no display memory property, it is impossible to stop energization for continuously applying an electric field.

  On the other hand, the display medium is sealed in the sealed space between the two substrates facing each other and at least one of which is transparent, and the display medium is moved by an electric field formed between the substrates. In a reversible information display panel that displays required information on the transparent substrate side, first, particles or powder fluid is used as a display medium. Become wider. In addition, an electric field is applied only when the display medium is moved, and even after the movement, no electric field is applied, so that the display medium stays at the position where it has been moved, and thus the display image is held (has 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 information, the display medium moves again to display other information, so that the information can be rewritten reversibly. Furthermore, since the display medium displays information directly, the size of the particles constituting the display medium determines the sharpness of the image. In the present invention, since a display medium composed of particles for a display medium having a particle diameter of 3 to 10 μm is used, a clear image can be displayed, and delicate and precise information display such as a barcode can also be performed. Therefore, when displaying a barcode or a QR code which is a two-dimensional barcode on the information display panel of the present invention, the reading accuracy can be significantly improved as compared with the case where a conventional liquid crystal or a thermal dye is used. .

Note that the one-dimensional barcode 1 shown in FIG. 1 and the two-dimensional barcode QR code 2 shown in FIGS. 3A and 3B simultaneously display other information (for example, product information) together with the barcode information. It is also possible to do. In that case, an information display area (not shown) for displaying other information is provided in addition to the barcode information information display area shown in FIG. 1 and FIGS. In the display area, two types of black and white display media with different charging characteristics enclosed between the substrates are used. In addition, an information display area (not shown) for displaying other information includes, for example, “a white background with a blue background. Two types of display media with different colors and charging characteristics enclosed between the substrates in order to make “white / blue display part for displaying characters” or “white / red display part for displaying white characters on a red background” By making the combination of “blue and white” or “red and white”, an easy-to-read barcode display can be performed.
In addition, the display medium sealed between the substrates can be suitably used when the object to be used contains a magnetic material by using a display medium mainly composed of insulating particles and not including magnetic particles. Become.

  Hereinafter, a reversible information display panel used for the above-described barcode will be described.

  FIGS. 4A to 4C are diagrams showing an example of the structure of the reversible information display panel used in the present invention. The reversible information display panel shown in FIG. 4A has different charging characteristics, for example, in a sealed space in which air is contained between two substrates 11 and 12 that are parallel to each other. A display medium 13 (a white display medium 13W composed of particles composed of particles for a white display medium and a black display) in which two types of display mediums (13W, 13B) composed of black and white two-color display medium particles are combined. And a black display medium 13B composed of a group of particles composed of medium particles). In the example shown in FIG. 4B, in addition to the example shown in FIG. 4A, for example, a partition 14 is provided in a lattice shape between the substrates 11 and 12 to form cells. Moreover, in FIG.4 (b), the partition in front is abbreviate | omitted. Further, in the example shown in FIG. 4C, the above-described display medium (13W, 13B) is sealed in a transparent capsule 17, and a plurality of capsules 17 (display medium 13) are mounted on the substrates 11, 12 without providing a partition. A reversible information display panel is arranged between them.

  FIGS. 5A to 5C are diagrams showing other examples of the structure of the reversible information display panel of the present invention. The reversible information display panel shown in FIGS. 5A to 5C has a conductive member 15 on the inner surface side of each of the substrates 11 and 12, in addition to those described with reference to FIGS. 16 and at least the conductive member 16 on the transparent substrate 11 side is a transparent conductive member.

  In such a reversible information display panel, an electric field is applied to display media 13W and 13B composed of two types of particles for display media having different charging characteristics, so that a display medium charged at a low potential has a Coulomb force or the like. Is attracted toward the high potential electric field direction, while the display medium charged at a high potential is attracted toward the low potential electric field direction, and the display medium moves in the moving direction as the electric field direction changes. The required information can be displayed on the transparent substrate 11 side.

  Therefore, as shown in FIGS. 4A to 4C and FIGS. 5A to 5C, the white display medium 13W and the black display medium particles each composed of a group of particles composed of the white display medium particles. In accordance with the electric field formed by the electric charge such as an electrostatic latent image applied to the outside of the substrates 11 and 12, the display medium 13 composed of the two-color display medium and the black display medium 13 </ b> B composed of the configured particle group is used. The display is displayed on the transparent substrate 11 by moving the display medium vertically between the two substrates and making the observer visually recognize the white display medium 13W or the black display medium 13B with the size of the display medium particles as a pixel unit. It can be carried out.

  In addition, in the reversible information display panel as shown in FIGS. 4A to 4C and FIGS. 5A to 5C, a white display medium 13W composed of particles composed of particles for white display medium is provided. The white display medium 13W composed of powder fluid composed of particles for white display medium and the black display medium 13B composed of particles composed of particles for black display medium from the powder fluid composed of particles for black display medium. The black display medium 13B can be replaced. Further, the combination of colors of the two-color display medium of the reversible information display panel can be any combination of various realizable colors as well as white and black as described above. .

  The reversible information display panel as described above encloses the display medium 13 in a sealed space between two opposing substrates 11 and 12 which are at least one transparent, and moves the display medium by applying an electric field to the display medium. The display panel is a reversible display panel for displaying information. Here, a particle group or a powder fluid is used as the display medium 13, and the display medium 13 is visually recognized through the transparent substrate 11, so that a large size such as black and white can be obtained. A wide viewing angle can be secured under contrast. Further, the information (display contents) is rewritten, that is, the electric field is applied only when the display media 13W and 13B are moved. After the movement, the display media 13W and 13B remain in the position where they have moved once without the effect of the electric field. Therefore, display information can be held for a long time. On the other hand, when information is to be rewritten, the display medium 13W, 13B is moved again to display other information by applying the electric field again, so that the information can be rewritten reversibly.

  Here, since the display media 13W and 13B display information directly, the size of the particles constituting the display media 13W and 13B determines the clarity of the information. Therefore, here, preferably, a display medium is composed of particles composed of particles for a display medium composed of particles having an average particle diameter of 3 to 10 μm, or the display medium is adjusted so that the particles for a display medium become a powder fluid. By doing so, the display of clear information is ensured and the display of delicate and precise information is enabled.

  Next, an example of information display, information rewriting, and information erasing in the reversible information display panel used in the present invention having the above-described configuration will be described.

  FIG. 6 is a diagram for explaining an example of information display on the reversible information display panel used in the present invention. In the reversible information display panel used in the present invention, as shown in an example in FIG. 6, some charge is applied to the external surface on the transparent substrate 11 side of the reversible information display panel in which the display medium 13 is sealed between the opposing substrates 11 and 12. When an electric charge is applied by the forming means 21, an electrostatic field is formed. In accordance with the electrostatic field, the negatively charged display medium is attracted by the Coulomb force toward the positively charged substrate part, and is charged positively toward the negatively charged substrate part. The display medium is attracted by Coulomb force or the like, and the display medium is attracted to the inner surface of the transparent substrate 11 and electrostatically attached, whereby information such as an image is displayed.

  This electrostatic latent image is formed by transferring an electrostatic latent image formed by an ordinary electrophotographic system using an electrophotographic photosensitive member onto the reversible information display panel of the present invention, or by ion flow. It can also be performed by a method such as directly forming an electrostatic latent image. As shown in FIG. 6, the display medium attracted to the inner surface of the transparent substrate 11 is adhered as it is even if the electrostatic field disappears, so that the display information is retained (memory) as it is. . FIG. 6 illustrates a positively charged white display medium 13W and a negatively charged black display medium 13B.

  FIG. 7 is a diagram for explaining an example of information rewriting in the reversible information display panel used in the present invention. When the panel on which information such as an image is once displayed is left as it is, as shown in an example in FIG. A new electrostatic field is formed. According to the newly formed electrostatic field, the display medium moves again, and the negatively charged display medium is attracted by the Coulomb force toward the positively charged substrate portion. A display medium charged to a positive polarity is attracted toward the charged substrate portion by Coulomb force or the like, and the display medium is attracted to the inner surface of the transparent substrate 11 and electrostatically attached, thereby displaying information such as an image. Rewritten. FIG. 7 illustrates a positively charged white display medium 13W and a negatively charged black display medium 13B.

  FIG. 8 is a diagram for explaining an example of display information erasure in the reversible information display panel used in the present invention. As shown in FIG. 8, charge forming means 22 and 23 are arranged on the outer surfaces of the substrates 11 and 12 of the display panel, and an alternating voltage is applied to the substrates 11 and 12, for example. Thereby, information such as images can be erased by supplying electric charges to the outer surfaces of the substrates 11 and 12 of the reversible information display panel.

  When the information display panel having the above-described configuration is used as the bar code display plate 1, it is preferable to make the respective substrates 11 and 12 made of a plastic material in order to realize thinning and weight reduction of the bar code display plate. .

  By the way, about the board | substrates 11 and 12 of an information display panel, those at least one board | substrate 11 is a transparent substrate which can confirm the color of a display medium from the outer side of a panel, and this board | substrate 11 has the high transmittance | permeability of visible light, and It is preferable to use a material having good heat resistance. The substrate 12 may be transparent or opaque. Examples of substrate materials include polymer sheets such as polyethylene terephthalate, polyethersulfone, polyethylene, polycarbonate, polyimide, and acrylic resin, flexible materials such as metal sheets, and flexibility such as glass and quartz. An inorganic sheet having no surface is mentioned.

  The thickness of the substrate is preferably 2 to 400 μm, more preferably 5 to 300 μm. If it is too thin, it will be difficult to maintain the strength and the uniformity of the distance between the substrates, and if it is thicker than 400 μm, there will be a disadvantage that the display medium will not move due to the force of an electric field such as an electrostatic latent image formed outside the substrate.

In addition, the constituent materials of the conductive members 15 and 16 provided on the substrate as necessary include metals such as aluminum, silver, nickel, copper, and gold, ITO, indium oxide, conductive tin oxide, and conductive zinc oxide. Examples thereof include conductive metal oxides such as polyaniline, polypyrrole, polythiophene, and the like, which are appropriately selected and used. As a method for forming a conductive member, the above-described materials are formed into a thin film by sputtering, vacuum deposition, CVD (chemical vapor deposition), coating, or the like, or a conductive agent is mixed with a solvent or a synthetic resin binder. Then, a method of coating is used.
In this case, the conductive member 16 provided on the viewing side substrate needs to be transparent, but the conductive member 15 provided on the back side substrate does not need to be transparent. In any case, the above-mentioned material that can form a pattern and is conductive can be preferably used.

  The thickness of the conductive member 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 conductive member 15 provided on the back side substrate are the same as those of the conductive member 16 provided on the viewing side substrate described above, but need not be transparent.

  Also, as for the partition 14 provided as necessary, the shape is appropriately set appropriately depending on the type of display medium related to the display, and thus cannot be specified unconditionally, but the width of the partition is 2 The height of the partition wall is adjusted to 10 to 100 μm, preferably 10 to 50 μm. In forming the partition walls, a double rib method in which ribs are formed on each of the opposing substrates 11 and 12 and then bonded, and a single 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 the schematic plan view of FIG. 9, the cells formed by the partition walls 14 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. Is exemplified by a lattice shape, a honeycomb shape, or a mesh shape. It is better to make the part corresponding to the partition part visible from the display surface side (the area of the cell frame part) as small as possible, and the clearness of information display increases.

  Here, 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. Any of these methods can be suitably used for the information display panel according to the present invention, and among these, a photolithography method using a resist film and a mold transfer method are suitably used.

  Next, display medium particles (hereinafter also referred to as particles) constituting the display medium 13 used in the information display panel will be described. The particles for the display medium can form a particle group by itself to form a display medium, form a particle group combined with other particles to form a display medium, or can be adjusted to become a powder fluid described later to be a display medium. However, in the present invention, a display medium configured with at least magnetic particles is not used. 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, acrylic urethane resin, acrylic urethane silicone resin, acrylic urethane fluororesin, acrylic fluororesin, silicone resin, acrylic silicone resin, epoxy resin, polystyrene, styrene acrylic resin Polyolefin, butyral resin, vinylidene chloride resin, melamine resin, phenol resin, fluororesin, polycarbonate, polysulfone, polyether, polyamide and the like, 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, polyamines, and imidazole derivatives.
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.

Examples of yellow colorants include 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.

  Moreover, it is preferable that the particles constituting the display medium 13 have a mean particle diameter d (0.5) in the range of 3 to 10 μm and are uniform and uniform. If the average particle diameter d (0.5) is larger than this range, the display is not clear. If the average particle diameter d (0.5) is smaller than this range, the cohesive force between the particles becomes too large, which hinders the movement of the display medium. .

Furthermore, here, regarding the particle size distribution of each particle, the particle size distribution Span represented by the following formula is set to 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 expressed in μm that the particle diameter is 50% larger than this and 50% smaller than this, and d (0.1) is the ratio of particles smaller than 10%. % Is a numerical value expressing the particle diameter in μm, and d (0.9) is a numerical value expressing the particle diameter in which 90% or less of the particles are less than this in μm.)
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 of each particle, the ratio of the d (0.5) of the particle having the minimum diameter to the d (0.5) of the particle having the maximum diameter among the used particles is 50 or less, preferably 10 or less. Is important.

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 the particle size distribution are obtained from a volume-based distribution. Specifically, using a Mastersizer2000 (Malvern Instruments Ltd.) measuring instrument, put particles into a nitrogen stream and use the attached analysis software (software based on volume-based distribution using Mie theory). Measurement of diameter and particle size distribution can be performed.

  Next, for example, the powder fluid used as the display medium 13 used for the information display panel will be described. For example, the applicant has obtained the right of “Electronic Powder Fluid (registered trademark): Registration Number 4636931” for the name of the powder fluid used as the display medium in the present invention.

  The “powdered fluid” here 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, a liquid crystal is defined as an intermediate phase between a liquid and a solid, and has fluidity that is a characteristic of a liquid and anisotropy (an optical property) that is a characteristic of a 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. Therefore, it has been found here 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 a powder fluid.

  That is, the pulverulent fluid in the present invention is an intermediate state having both particle and liquid properties, as in the definition of liquid crystal (liquid and solid intermediate phase), and the gravity characteristic that is the characteristic of the particles described above. 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, in a dispersion system in which a solid or liquid substance is stably suspended as a dispersoid in a gas. In the information display panel according to the present invention, a solid substance can be obtained as a dispersoid. To do.

  The information display panel according to the present invention comprises a powder fluid exhibiting high fluidity in an aerosol state in which solid particles are stably suspended as a dispersoid, for example, as a display medium between 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, this powdered fluid is a substance in an intermediate state of both fluid and particle characteristics that exhibit fluidity by itself without borrowing the force of gas or liquid. The powder fluid can be in an aerosol state in particular, and in the information display panel according to the present invention, a solid substance is used in a state of being relatively stably suspended as a dispersoid in the gas.

  The charge amount of the display medium particles naturally depends on the measurement conditions, but the charge amount of the display medium particles in the information display panel is almost the initial charge amount, the contact with the partition wall, the contact with the substrate, the charge associated with the elapsed time. It was found that depending on the attenuation, the saturation value of the charging behavior of the particles for the display medium is a dominant factor.

  In addition, when used in a dry information display panel that uses particles or powdered fluid composed of particles for display media as they are as the display medium, it is important to manage the gas in the void surrounding the display medium between the panel substrates. Contributes to the improvement of stability. Specifically, it is important that the relative humidity at 25 ° C. is 60% RH or less, preferably 50% RH or less, and more preferably 35% RH or less. When used in a dry information display panel in which a particle group composed of particles or powdered fluid is enclosed in a capsule and used as a display medium, the management of the gas in the void surrounding the display medium between the panel substrates is not so important. .

  4A to 4C and FIGS. 5A to 5C, the voids are defined by the conductive members 15 and 16 (conductive members from the portions sandwiched between the opposing substrates 11 and 12. In this case, the gas portion in contact with the so-called display medium 13 excluding the occupied portion of the display medium 13, the occupied portion of the partition wall 14 (when the partition wall is provided), and the seal portion of the information display panel.

  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 information display panel so that the humidity is maintained. For example, filling of the display medium, assembly of the information display panel, etc. are performed in a predetermined humidity environment. It is important to apply a sealing material and a sealing method that prevent moisture from entering.

Here, the distance between the substrate 11 and the substrate 12 in the information display panel may be adjusted to 10 to 100 μm, preferably 10 to 50 μm, as long as the display medium can be moved and the contrast can be maintained. The volume occupation ratio of the display medium 13 (particle group or powder fluid) in the space between the opposing substrates is preferably 5 to 70%, more preferably 5 to 60%. When it exceeds 70%, the movement of the display medium 13 is hindered, and when it is less than 5%, the contrast tends to be unclear.
The total thickness of the reversible information display panel of the present invention is preferably 10 μm or more and less than 1 mm.

  The bar code display board using the reversible information display panel of the present invention can display a clear bar code and can display new information any number of times after the displayed information is securely erased. Therefore, it is not necessary to perform predetermined printing or the like on the paper, and the cost and the man-hours required for the printing can be greatly suppressed, and it can be suitably used for the purpose of sufficiently preventing the consumption of resources.

It is a top view which shows the one-dimensional barcode which is one Embodiment of this invention. It is a figure for demonstrating the bar and space which comprise the one-dimensional barcode which is one Embodiment of this invention. (A) is a top view which shows QR code which is other embodiment of this invention, (b) is a top view which shows QR code of (a) with the board | substrate which is a display part of a barcode. (A)-(c) is a figure which shows an example of the structure in the reversible information display panel used by this invention, respectively. (A)-(c) is a figure which shows the other example of the structure in the reversible information display panel of this invention, respectively. It is a figure for demonstrating an example of the information display in the reversible information display panel used by this invention. It is a figure for demonstrating an example of the display information rewriting in the reversible information display panel used by this invention. It is a figure for demonstrating an example of the information deletion in the reversible information display panel used by this invention. It is an approximate line top view showing the example of arrangement of the cell divided by the partition.

Explanation of symbols

1 Bar code display plate 2 QR code 11, 12 Substrate 13 Display medium (particle group or powdered fluid)
13W White display medium 13B Black display medium 14 Bulkhead 15, 16 Conductive member 17 Capsule 21, 22, 23 Charge forming means

Claims (5)

A reversible type in which a display medium is enclosed in a sealed space between two substrates facing each other and at least one of which is transparent, and the display medium is moved by an electric field to display necessary information on the transparent substrate side. A bar code display board having a display unit comprising an information display panel,
Using two types of black and white display media, each consisting of two types of black and white display media particles, each having different charging characteristics and an average particle diameter in the range of 3 to 10 μm, and the total thickness of the information display panel is 10 μm or more The reversible bar code display board is characterized by being less than 1 mm.   2. A reversible bar code display panel using a reversible information display panel according to claim 1, wherein the display medium sealed between the substrates is mainly composed of insulating particles and does not contain magnetic particles.   The thickness between at least one of the two substrates is 0.4 mm or less, and the distance between the substrates formed by the two substrates facing each other is 0.1 mm or less. Or the reversible bar code display board of 2.   The reversible bar code display plate according to any one of claims 1 to 3, wherein each substrate is made of a plastic material.   The reversible bar code display according to any one of claims 1 to 4, wherein a particle group composed of particles for display medium or a powder fluid composed of particles for display medium is used as the display medium. Board.

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