JP2005134739A - Method for manufacturing display unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily manufacturing a display unit which has an independently rotatable columnar display element enclosed in a transparent hollow cylinder, with the surface of the display element is divided into regions of different colors for display and with the display element polarized into two poles of different electrification states from each other. <P>SOLUTION: The method for manufacturing a display unit includes: a hollow cylinder forming step to form the hollow cylinder sealing at least one display element by cutting a hollow fiber having at least one display element inside and sealing the cut faces by using a laser; and a display element cutting step to cut at least one display element sealed in the hollow cylinder into at least two parts by a laser. A laser of identical wavelength is used in the above hollow cylinder forming step and in the display element cutting step. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a display unit constituting various display devices.

Conventionally, various display devices such as a display of an information processing terminal such as a personal computer, a mobile phone, and a mobile terminal, or a display body that can acquire information from these terminals and carry it independently, such as an electronic paper or an electronic book. A device has been proposed.
Among them, as a display device that can be used for electronic paper, electronic books, and the like, a display device including a display unit including spherical display elements that are color-coded by hemisphere has been proposed (for example, Patent Documents 1 and 2). reference).

FIG. 6 shows a schematic cross-sectional view of such a display device. In this display device 65, as shown in FIG. 6A, a spherical display element 61 is enclosed with a dielectric liquid 64 in a spherical gap 63 formed in an optically transparent plate-like substrate 62. The capsule structure has a structure in which a plurality of capsule structures are dispersed in the substrate 62. Further, on the front and back surfaces of the base 62, a transparent electrode 68a composed of the electrodes 66a and 66b and the transparent panel 67a and a transparent electrode 68b composed of the electrodes 66c and 66d and the transparent panel 67b are in close contact with each other. The transparent electrode is made of a transparent conductive film such as indium tin oxide (ITO).
As shown in FIG. 6B, the spherical display element 61 is color-coded into hemispheres 61a and 61b in different colors, and is polarized in two differently charged states, and is connected to the electrodes 66a and 66c. When an electric field is applied from the power source 69a or the power source 69b connected to the electrodes 66b and 66d, the display elements dispersed in the region rotate to form an image.
Moreover, the thing similar to the above and the particle | grains of a cylindrical piece shape are also disclosed (for example, refer patent document 3).

That is, in general, when particles are present in a dielectric liquid, charge is transferred between the particles and the dielectric liquid by applying an electric field, and the particles are charged positively or negatively and an electric double layer is formed. The The display element as described above is adjusted so that the surface has at least two regions having different colors and two regions having different charging characteristics in the dielectric liquid. Therefore, when an electric field is applied to such a display element, a torque is applied to the display element so as to align the polar direction with the electric field direction. As a result, the display element rotates to align any hemisphere in one direction. If the direction of the electric field is reversed, the display element is inverted, the displayed color region changes, and the reflected color of the display changes.
Since such a display device is a light-receiving type, it is easy to adjust to eyes like a printed matter, and is expected as a display device free from eye fatigue caused by flicker caused by external light.

  As a manufacturing method of such a display device, for example, the following method is used. First, a plurality of display elements as described above are mixed with an uncured elastomer, formed into a thin sheet, and then thermally cured. Next, the sheet-like elastomer is immersed in a dielectric liquid such as an organic solvent or oil. This dielectric liquid acts as a plasticizer and swells the elastomer. Since this elastomer swells almost uniformly, voids are generated around each display element. At the same time, the space is filled with a dielectric liquid. As a result, the display element is disposed in the gap via the dielectric liquid, and is supported so as to be freely rotatable in the gap, and is color-coded, for example, for each hemisphere as shown in FIG. An elastomer sheet is obtained in which the display element is sealed in the spherical gap 3 via the dielectric liquid 4. A display device is manufactured by disposing the elastomer sheet between the opposing transparent electrodes.

  However, in practice, there are various problems in such a manufacturing method and the display device obtained thereby. That is, in the case of the above-described manufacturing method, a complicated process is required such that thermosetting is required after the sheet is formed or that the sheet is immersed in a dielectric liquid. Moreover, since the space | gap 3 is formed by swelling of an elastomer, the kind of liquid which can be used for this is restrict | limited. Further, since the swelling state depends on the temperature, it is difficult to obtain a spherical void 3 having a uniform size and excellent shape, that is, a constant diameter. Due to such variations, there has been a problem that a target image cannot be formed with good reproducibility. That is, if the gap is not large enough for the display element or the shape thereof is distorted, free rotation of the display element in the gap is hindered. When the display element rotates according to the electrical anisotropy to form an image, the rotation necessary for image display (generally 180 °) cannot be obtained. On the other hand, when the gap is too large for the particles, the ratio of the dielectric liquid part not involved in image display to the display element part involved in image display becomes relatively large, and a good image with high contrast can be obtained. It becomes difficult to obtain.

  In order to overcome the problems in manufacturing and quality of the display device, the present inventors have solved the problem with "spherical, ellipsoidal or columnar display elements, and a single display element. Or a display unit in which a plurality are enclosed in a transparent hollow cylinder, and the surface of the display element is divided into regions of different colors for display, and the display element has at least two electrodes with different charged states The display unit is characterized in that all the display elements are independently rotatable inside the hollow cylinder, and a display device including the display unit is proposed. For example, Patent Document 4 proposes a display device in which a plurality of display units in which a plurality of display elements are enclosed in a hollow cylinder together with a dielectric liquid are arranged in a display region.

According to the configuration of the display unit described in Patent Document 4, since the display units are individually independent, manufacturing by a simple method such as coating is possible. For example, the display unit is dispersed in a liquid and manufactured by coating it on a sheet-like support, or spread on a mesh-like support, and the display units are entangled with each other by removing the liquid to form a sheet. Can be manufactured. When manufacturing, if the display unit is oriented in a certain direction, the display units can be arranged in parallel, and if they are stacked in the orthogonal (vertical) direction, it is also possible to form a display area in a grid pattern. . In addition, since the display element or liquid is sealed in the display unit, the liquid for sealing can be arbitrarily selected. If a melt spinning method or the like is used as a method for producing the hollow cylinder as the display unit, the hollow cylinder can be formed with higher accuracy than the formation of spherical voids by swelling. This makes it possible to form a good image without hindering the rotation of the display element. Furthermore, when the cross-section of the side surface of the transparent hollow cylinder enclosing the liquid is circular, the so-called convex lens effect allows the internal display element to appear thicker than it actually appears, so it appears to occupy the entire display area. The area of the display element is increased, and as a result, good contrast can be obtained.
US Pat. No. 4,126,854 (FIG. 1) JP-A-1-282589 (page 6, FIG. 1) JP 2000-89260 A (page 2-3, FIG. 3) Japanese Patent Laid-Open No. 2002-202536 (page 6, FIG. 1)

However, in the production of such a display unit, the display element is mainly cut finely using a solid blade such as a rotary blade or a straight blade, the display element is inserted into a transparent hollow fiber, and the hollow fiber is In addition, cutting with a heated cutter and sealing the cut surface was very laborious and had a problem in productivity.
Accordingly, an object of the present invention is to easily manufacture using a laser beam in manufacturing a display unit of a light-receiving display device that is easy to adjust to eyes like printed matter and does not cause eye fatigue due to external light. .

  In the present invention, an independently rotatable column-shaped display element is enclosed in a transparent hollow cylinder, and different color regions for display are divided on the surface of the display element. And it aims at providing the manufacturing method which can manufacture simply the display unit in which this display element is polarized by two differently charged states.

  As a result of intensive studies, the inventors of the present invention perform cutting of the hollow fiber and sealing of the cut surface and cutting of the display element with a laser having the same wavelength, or cutting of the hollow fiber and sealing of the cut surface. Alternatively, the present inventors have found that the above problems can be solved by using a semiconductor laser or an yttrium-aluminum-garnet crystal laser for cutting the display element, and have completed the present invention.

The present invention includes the following embodiments.
[1] A columnar display element that can be rotated independently is enclosed in a transparent hollow cylinder, and different color regions for display are divided on the surface of the display element, and A method of manufacturing a display unit in which the display element is polarized in two differently charged states,
Formation of a hollow cylinder that forms a hollow cylinder in which at least one display element is enclosed by cutting a hollow fiber having at least one display element inside by laser and sealing the cut surface Process,
A display element cutting step of cutting at least one display element enclosed in the hollow cylindrical body into at least two by a laser, and in the hollow cylinder forming step and the display element cutting step, A method of manufacturing a display unit using a laser.
[2] The method for manufacturing a display unit according to [1], wherein a semiconductor laser or an yttrium-aluminum-garnet crystal laser is used as the laser.
[3] A columnar display element that can rotate independently is enclosed in a transparent hollow cylinder, and different color regions for display are divided on the surface of the display element, and A method of manufacturing a display unit in which the display element is polarized in two differently charged states,
A display element cutting step of cutting at least one display element enclosed in the hollow cylindrical body into at least two by a laser, and using a semiconductor laser or an yttrium-aluminum-garnet crystal laser as the laser A manufacturing method of a display unit characterized by the above.
[4] A columnar display element that can rotate independently is enclosed in a transparent hollow cylinder, and different color regions for display are divided on the surface of the display element, and A method of manufacturing a display unit in which the display element is polarized in two differently charged states,
Formation of a hollow cylinder that forms a hollow cylinder in which at least one display element is enclosed by cutting a hollow fiber having at least one display element inside by laser and sealing the cut surface A method of manufacturing a display unit, comprising: a step of using a semiconductor laser or a yttrium-aluminum-garnet crystal laser as the laser.
[5] The method for manufacturing a display unit according to any one of [1], [3], and [4], wherein a semiconductor laser is used as the laser.

  According to the present invention, a columnar display element that can be rotated independently is enclosed in a transparent hollow cylinder, and different color regions for display are divided on the surface of the display element. In addition, it is possible to easily manufacture a display unit in which the display element is polarized in two differently charged states.

Hereinafter, the present invention will be described in detail.
In the manufacturing method of the present invention, an independently rotatable column-shaped display element is enclosed in a transparent hollow cylinder, and different color regions for display are divided on the surface of the display element. And a display unit in which the display element is polarized in two differently charged states.

“Aspect [1]”
First, the above aspect [1] will be described. In the aspect [1], a hollow cylindrical body in which at least one display element is enclosed is obtained by cutting a hollow fiber having at least one display element therein and sealing the cut surface with a laser. A hollow cylinder forming step to be formed, and a display element cutting step of cutting at least one display element sealed in the hollow cylinder into at least two by a laser, and the hollow cylinder forming step and In the display element cutting step, a laser having the same wavelength is used.

≪Hollow tube forming process≫
The display element used in the present invention has a columnar shape, and has a surface in which regions of different colors for display are divided and is polarized into two electrodes having different charged states. Such a display element enclosed in a hollow cylinder so as to be independently rotatable is rotated by an external electric field to display an image.

The method of polarizing the display element to two different polarities includes formation of electret fibers, mixing of ionic substances in the resin, mixing of magnetic substances in the resin, coating of different substances on a single substance, etc. For example, vapor deposition.
Examples of materials used for coating and vapor deposition include charge control agents that also serve as colorants, such as nigrosine and salicylate, and metal salts such as MgCl ₂ , CaCl ₂ , and MgF ₂ , but are limited thereto. It is not something.
The polarization of the charged state mentioned here includes not only electrical plus / minus combinations but also strong plus / weak plus, strong minus / weak minus, and the like.

As a method of separating at least two different color regions for display on the surface of the display element, a method of vapor-depositing or coating two or more kinds of colorants on the surface of the display element, ionicity as described above Prepare two or more resins with different colors, such as a single color of the resin itself mixed with a substance or magnetic substance, and other methods such as vapor deposition or coating of one or more colorants, mixing of colored substances, etc. And a method using side-by-side fibers obtained by co-extrusion of these.
At least one color region on the surface of the display element uses a color that absorbs the wavelength of the laser used for cutting the display element in the display element cutting step described later. Typically, it is divided into two color regions of light color and dark color.
As an example of such a division, for example, the case where the circumferential half side surface of the pillar piece is white and the remaining circumferential half side surface is black is exemplified. As a material (colorant or coloring substance) used for such classification, for example, titanium dioxide is used for white type, carbon black is used for black type, “Nigrosine” (manufactured by Wako Pure Chemical Industries, Ltd.), etc. .

  The shape of the display element is a columnar shape and is not particularly limited as long as it can be independently rotated in the hollow cylinder, and is a columnar piece such as a true columnar piece or an elliptical column piece; a triangular column piece, a square column piece Or a prismatic piece such as a hexagonal prism piece; or an irregular columnar piece such as a star in cross section. In addition, the above-described color coding is configured to have two or more regions regardless of the shape.

  Materials constituting the display element include acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylic resin, vinyl chloride-vinyl acetate copolymer (vinyl chloride resin), nylon resin, polyolefin resin, polyester resin, urethane resin, etc. Is mentioned.

  As a material constituting the hollow fiber, a transparent material is used so that a display element enclosed inside the hollow cylinder can be visually recognized from the outside. Examples of such transparent materials include polyester resins, polyolefin resins, acrylic resins, urethane resins, polystyrene resins, ABS resins, silicon resins, nylon resins, and vinyl chloride resins.

The hollow cylinder can be formed, for example, as described in the following (1) to (4).
(1) First, a substantially concentric two-layered polymer fiber is produced by a melt spinning method or the like, and the fiber is drawn to obtain a fiber having an outer shape of about 20 to 200 μm. At this time, the resin constituting the inner layer is a resin that dissolves in water or an organic solvent after molding. A hollow fiber can be obtained by dissolving the resin of the inner layer with water or an organic solvent and removing the resin of the inner layer. Alternatively, if a fluid is introduced in advance instead of the soluble resin in the inner layer, it is not necessary to remove the resin later, and the hollow fiber can be manufactured more easily. As the fluid to be introduced at this time, a gas such as nitrogen gas or air is preferable.
Next, a dispersion liquid in which display elements are dispersed in advance is prepared, and the dispersion liquid is impregnated into the transparent hollow fiber to obtain a hollow fiber having at least one display device therein. Specifically, as the impregnation method, a large number of hollow fibers are bundled and placed in a chamber, the chamber is evacuated, and then a dispersion in which display elements are dispersed is introduced into the chamber. It can be filled with hollow fibers.

  A liquid having a dielectric property is used as the liquid for dispersing the display element. The liquid preferably has a specific gravity close to that of the display element. When the specific gravity of the liquid is too large, the display element comes into strong contact with the inside of the hollow cylinder because of the buoyancy applied to the display element, and when it is too small, the gravity is applied to the display element. This is because there is a risk of hindering the rotational movement when applied. If an appropriate liquid cannot be found, the liquid may be composed of a two-liquid system having a specific gravity larger than that of the display element and a smaller liquid. For example, as the liquid having dielectric properties, silicone oil alone or a combination of a liquid having a high specific gravity such as tetrachloroethylene or a fluorine-based liquid and a liquid having a low specific gravity such as “Isopar G” (manufactured by Exxon Chemical Co., Ltd.) Can be mentioned.

  Next, the hollow fiber having at least one display element is formed by sealing each cut surface while cutting (melting) the hollow fiber having the display element in an arbitrary length with a laser.

(2) First, a polymer fiber having a substantially concentric three-layer structure is manufactured by a melt spinning method or the like, and the fiber is drawn to obtain a fiber having an outer shape of about 20 to 200 μm. In this case, the innermost layer is a layer constituting a display element, the outermost layer is a layer constituting a hollow fiber, and the intermediate layer is a solvent-soluble layer.
Next, the outermost layer to the innermost layer are cut in a direction perpendicular to the length direction of the obtained fiber, and the intermediate layer is dissolved by immersing this fiber in a solvent that dissolves only the intermediate layer to form a display element. To obtain hollow fibers having inside fibers.
At this time, the specific gravity of the solution after dissolving the intermediate layer with the solvent is preferably equal to the specific gravity of the display element for the same reason as described above.
Next, the hollow fiber having at least one display element is formed by sealing each cut surface while cutting (melting) the hollow fiber having the display element in an arbitrary length with a laser.

(3) A substantially concentric two-layered polymer fiber is produced by a melt spinning method or the like, and the fiber is drawn to obtain a fiber having an outer shape of about 20 to 200 μm. In this case, the inner layer is a layer constituting a display element, and the outer layer is a layer constituting a hollow fiber. In this melt spinning, a hollow fiber having fibers constituting the display element therein can be obtained by interposing a peelable material such as silicone oil between the polymer layers.
The peelable material such as silicone oil used at this time preferably has a specific gravity equivalent to the specific gravity of the display element as in the solutions in the methods (1) and (2).
Next, the hollow fiber having at least one display element is formed by sealing each cut surface while cutting (melting) the hollow fiber having the display element in an arbitrary length with a laser.

(4) A substantially concentric three-layer polymer fiber is produced by a melt spinning method or the like, and the fiber is drawn to obtain a fiber having an outer shape of about 20 to 200 μm. At this time, the innermost layer is a layer constituting a display element, the outermost layer is a layer constituting a hollow fiber, and the intermediate layer is a light-soluble layer.
Next, each cut surface is sealed while being cut with a laser from the outermost layer to the innermost layer in a direction perpendicular to the length direction of the obtained fiber.
Next, when the cut fiber is irradiated with light, the light passing through the transparent outermost layer dissolves the light-soluble intermediate layer, and a hollow cylinder having a columnar display element inside is obtained.
At this time, the innermost layer may be cut into a plurality of pieces in advance, and the display element in the cylinder may be cut into a plurality of pieces. Further, the specific gravity of the solution obtained by dissolving the intermediate layer with light is preferably equal to the specific gravity of the display element as in the solutions in the methods (1) and (2).

≪Display element cutting process≫
Next, a display element cutting step is performed by cutting at least one display element enclosed in the hollow cylinder obtained as described above into at least two pieces by laser. FIG. 1 shows a conceptual diagram thereof. In FIG. 1, one display element 12 whose ends are cut with a laser and sealed in a sealed hollow cylinder 11 is cut with a laser to form fine display elements 13a, 13b, and 13c. Yes. At this time, the hollow cylinder 11 is not cut by a laser for cutting the display element.

≪Laser≫
In this mode [1], in each of the above steps, the laser used for cutting the hollow fiber and sealing the cut surface and the laser used for cutting the display element enclosed in the hollow cylinder have the same wavelength. Is used.
That is, in the present invention, a display element having a color region with high laser light absorptivity is disposed in a transparent hollow cylinder. Therefore, when the hollow cylinder is irradiated with laser light from the outside, when the laser output is low, the laser beam is transparent without damaging the transparent hollow cylinder as shown in the conceptual diagram of FIG. , And when it reaches the surface of the display element, it becomes a heat source and melts the display element. As a result, only the display element inside the hollow cylinder is selectively cut to an arbitrary length, and a display element that can be rotated independently is formed. On the other hand, when the output is given, the cut surface is sealed at the same time as the transparent hollow cylinder is cut.

That is, in the present invention, both the cutting of the hollow fiber and the sealing of the cut surface and the cutting of the display element enclosed in the hollow cylinder are performed by adjusting the output without changing the wavelength of the laser beam. be able to.
According to such a cutting method using a laser, the following features are further expressed.
・ Because light can be focused on a small beam size, local cutting is possible.
・ Cutting conditions such as laser power and beam size can be controlled accurately.
・ There is no noise and vibration, and the working environment is improved.

Generally, lasers vary depending on the type of medium, such as solid lasers such as yttrium-aluminum-garnet crystal lasers (hereinafter abbreviated as YAG lasers), gas lasers such as carbon dioxide (CO ₂ ) lasers, and semiconductor lasers. a There are types of lasers, conventionally, processing laser is commonly used in production site is a CO ₂ laser, a CO ₂ laser is relatively inexpensive, the output is high, because the handling is easy, the resin Widely used for cutting and drilling. However, since the oscillation wavelength is around 10.6 μm and there is almost no permeability to the material constituting the hollow cylinder, it is not suitable for cutting display elements that require a process of transmitting through the transparent hollow cylinder. Also, the device is very large and has the disadvantage of being difficult to use.
Therefore, in the present invention, as a laser capable of cutting the hollow fiber, sealing the cut surface, and cutting the display element enclosed in the hollow cylinder at the same wavelength, it is easy to transmit through the transparent hollow cylinder. A laser beam having a wavelength that does not damage the transparent hollow cylinder at a low output, and can cut the transparent hollow cylinder with heat if the output is sufficiently increased is used. As such a laser, a semiconductor laser or a YAG laser is preferably used.

A YAG laser has a high light collecting property, can emit a short pulse with a high peak, and has an oscillation wavelength in the vicinity of 1.06 μm, which is transparent, so that it passes through a transparent hollow cylinder. Therefore, at a low output, only the display element inside the hollow cylinder can be arbitrarily cut. On the other hand, by sufficiently increasing the output, the hollow cylinder can be melted at the same wavelength. The device is also smaller than the CO ₂ laser.
The output of the YAG laser can be preferably used in the range of about 0.5 to 1000 W.

Semiconductor lasers are lasers that are not as high in condensing properties as CO ₂ lasers and YAG lasers, but have recently been used for processing. It can be said that the present invention is suitable for applications such as metal processing that do not require high light condensing properties as in the case of manufacturing the display unit of the present invention. In general, devices with various wavelengths from an oscillation wavelength of 600 nm to 980 nm are commercially available, and a wavelength suitable for a transparent hollow cylinder or a display element as a target can be selected.
In addition, since the semiconductor laser passes through the transparent hollow cylinder, at a low output, only the display element inside the hollow cylinder can be arbitrarily cut. On the other hand, by sufficiently increasing the output, the semiconductor laser is hollow at the same wavelength. The tube can be melted.
Furthermore, the semiconductor laser has advantages such as small size, easy microfabrication, simple oscillator structure and easy maintenance, and is most preferably used in the present invention.
Semiconductor laser elements include gallium arsenide (GaAs) (wavelength 600 to 800 nm).
The output of the semiconductor laser can be preferably used within a range of about 0.1 to 500 W.

The display element is preferably cut by the laser so that the length in the direction perpendicular to the section cut by the laser is about 5 to 100 μm.
On the other hand, the cutting of the hollow fiber by the laser is preferably performed such that the length in the direction perpendicular to the cross section cut by the laser is 5 μm to the width of the display device, and further from 1 mm to the width of the display device. It is preferable to carry out such that

  FIG. 2 shows an example of a display unit manufactured by the manufacturing method of this aspect. In this display unit 1, three columnar display elements 3a, 3b, 3c are sealed in a cylindrical transparent hollow cylinder 2 whose ends are sealed. The surfaces of the display elements 3a, 3b, and 3c are color-coded into two regions A and B having different colors and charged states, respectively. The hollow cylinder 2 contains the dielectric liquid 4 together with the display elements 3a, 3b, and 3c. The display elements 3a, 3b, and 3c rotate independently in the hollow cylinder 3, respectively. It is possible.

“Aspect [3]”
Next, the aspect [3] of the present invention will be described. Aspect [3] has a display element cutting step of cutting at least one display element sealed in the hollow cylinder into at least two by a laser, and a semiconductor laser or a YAG laser is used as the laser It is characterized by.
The display element cutting step in this embodiment [3] can be performed in the same manner as the display element cutting step in the above embodiment [1].
As the laser, a semiconductor laser is preferably used for the same reason as described above.

On the other hand, in this embodiment [3], the formation of the hollow cylinder, that is, the cutting of the hollow fiber and the sealing of the cut surface may be performed by a laser, or by a rotary blade or a straight blade.
In addition, if the laser is also a semiconductor laser or a YAG laser, it is not always necessary to use a laser having the same wavelength as that of the display element cutting step. For example, the wavelength at which the hollow fiber is cut does not pass through the resin constituting the hollow fiber. The laser may be used. For example, the CO ₂ laser is suitable for so-called fusing that cuts the transparent hollow cylinder and seals the cut surface. However, considering the simplicity of the manufacturing process, it is preferable to carry out at the same wavelength.

  By the manufacturing method of this aspect, a display unit manufactured by the manufacturing method of the above aspect [1], for example, a display unit having the same configuration as the display unit 1 shown in FIG. 2 can be manufactured.

“Aspect [4]”
Next, the aspect [4] of the present invention will be described. In the aspect [4], the hollow fiber body in which at least one display element is enclosed is obtained by cutting a hollow fiber having at least one display element therein and sealing the cut surface with a laser. It has a hollow cylinder forming step to be formed, and a semiconductor laser or a YAG laser is used as the laser.
The hollow cylinder formation process in this aspect [4] can be performed similarly to the hollow cylinder formation process in said aspect [1].
As the laser, a semiconductor laser is preferably used for the same reason as described above.

On the other hand, in this aspect [4], the display element may be cut by a laser, or by a rotary blade or a straight blade.
The display element need not be cut after the hollow cylinder is formed. The display element cut by a laser, a rotary blade, or a straight blade is placed in a hollow fiber, and this is cut by a laser to form a hollow cylinder. It is good.

  By the manufacturing method of this aspect, a display unit manufactured by the manufacturing method of the above aspect [1], for example, a display unit having the same configuration as the display unit 1 shown in FIG. 2 can be manufactured.

<Display device>
The display unit manufactured by the display unit manufacturing method of the present invention is used for manufacturing a display device.
The display device is formed into a sheet shape by, for example, applying a dispersion of the display unit in a liquid on a very thin sheet-like support. Or you may shape | mold as a sheet | seat by the entanglement of a some display unit by spreading on a mesh-shaped support body and removing a liquid component from the said dispersion liquid.
Information can be entered, erased, and rewritten by arranging, for example, a device for applying an electric field in each part of the sheet. A known means can be applied to the device for applying an electric field.

  When an electrode plate is installed in the display unit, glass is generally used as the material of the upper electrode plate, but transparent plastic, for example, polycarbonate resin, or polymethyl methacrylate or styrene in the case of acrylic Then, a styrene-acrylonitrile copolymer or the like may be used. The electrode plate is preferably formed by depositing ITO. On the other hand, in the case of the electrode plate installed on the lower side, since transparency is not particularly required, a highly opaque material may be used.

  As described above, since the display elements are designed to be polarized in two differently charged states, when an electric field is applied to the display device from the outside in accordance with an image signal, each display element has a surface charge of the electric field. The direction is changed according to the direction of the electric field using the force received by the driving force as a driving force. Of the colors on the outer peripheral surface of the display element, the color corresponding to the image signal is visible from the outside through the transparent cylinder. Once the display element is turned and fixed, even if the electric field is removed, static friction acts between the outer peripheral surface of the display element and the inner peripheral surface of the cylinder, or between the outer peripheral surface of the display element and the sealed liquid. The fixed state, that is, the display state is held by the force.

  The portion of the column seen from the surface of the display device in which the display elements are arranged is the color of one dot, and a plurality of dots display characters and images.

Hereinafter, an example of a display device using a display unit manufactured by the manufacturing method of the present invention will be described with reference to the drawings.
FIG. 3 is a schematic diagram of the display device 30. The display device 30 includes an image display unit 32 in which a plurality of display units 31 enclosing eight display elements are arranged in parallel, and electrodes arranged above and below the image display unit 32 to apply an electric field to each display element. A plate (not shown), power sources 33a and 33b, and wirings 34a and 34b for connecting the power sources 33a and 33b to the electrode plates are provided.
In addition, in FIG. 3, the hollow cylinder (outer cylinder) of each display unit 31 is not illustrated correctly, but it has the same configuration as shown in FIG. In addition, at least the upper electrode plate is transparent.

4 is a schematic cross-sectional view of one display unit 31 in the display device 30. FIG. 4A shows an image display state before driving the display device and FIG. 4B shows an image display state after driving the display device. .
In this display device 30, due to the electric field generated between the two electrode plates, a rotational moment due to the Coulomb force is generated for any display element in the display unit 31, and an arbitrary outer peripheral surface of the display element can be seen. In addition, the display element corresponding to one electric field may be single or plural.

  In FIG. 3, the length of the display unit 31 is equal to the width of the image display unit 32 and the display units 31 are arranged in parallel, but the length of the display unit 31 may be shorter than this. In addition, the display unit 31 may be arranged in an intertwined state instead of being arranged in parallel.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
Example 1
<Creation of display element>
A cylindrical piece of display element having the same configuration as shown in FIG. 2 was produced using polystyrene fibers. That is, a heat-resistant acrylic adhesive layer having a thickness of 50 μm was applied to one surface of a substrate made of a polyester film having a width of about 10 cm. Polystyrene yarns (thickness: about 100 μm, manufactured by Shinko Seisen Kogyo Co., Ltd.) cut to a length of about 9 cm were arranged in a single layer on the adhesive layer. This yarn is arranged in such a manner that after sufficiently spreading the yarn onto the adhesive layer of the substrate, the yarn is applied to the adhesive layer by rolling with a silicon rubber roller or the like through a polytetrafluoroethylene sheet having a thickness of 50 μm. Crimping was done so that the portion was buried. Thereafter, the excess yarn floating from the pressure-sensitive adhesive layer was removed by hand, and the yarns were bonded to the substrate in a single layer. At this time, by adjusting the thickness of the adhesive layer to 50 μm in advance, the thread was embedded in the adhesive layer so as to be about half the outer circumference.

Further, a paint (Nigrosine (reagent, manufactured by Wako Pure Chemical Industries, Ltd.) 1.9% by mass toluene solution) was used to color the entire semi-peripheral surface where the yarn was not buried in black. The semi-peripheral surface colored with this paint takes a surface charge distribution state different from the non-colored semi-peripheral surface.
Thereafter, the polystyrene yarn was peeled from the adhesive while the substrate was immersed in ethanol from the surface opposite to the surface where the polystyrene yarn was buried to dissolve the adhesive layer. The semi-peripheral surface buried in the adhesive layer was not colored, and the semi-peripheral surface exposed from the adhesive layer was colored black.
The polystyrene yarn was cut with a cutter so that the cut length was approximately 5 to 8 mm.

<Formation of hollow cylinder>
Next, a hollow cylinder was produced. Using an extruder having a die discharge hole 51 shown in FIG. 5, while flowing nitrogen gas from the gas discharge hole 52 at the center of the die discharge hole 51, the polyester resin is discharged from the resin discharge holes 53 around the center. Extruded. The extruder temperature was 250 ° C., and nitrogen gas was maintained at almost atmospheric pressure. The extrusion rate of the melted polyester resin was 0.15 kg / hr. The molten fiber at the exit of the extruder was stretched to obtain a hollow fiber having an outer diameter of 270 μm and an inner diameter of 160 μm.

  Subsequently, a large number of the hollow fibers were bundled and placed in a chamber, the chamber was evacuated, and a liquid in which the polystyrene yarn was dispersed was introduced into the chamber, thereby filling the hollow fibers with the dispersion. At this time, silicone fluid TSF451-10 (manufactured by GE Toshiba Silicone Co., Ltd.) was used as the liquid for dispersing the display element.

  Thereafter, the hollow fiber containing polystyrene yarn and liquid therein was cut with a semiconductor laser UDL-15V (manufactured by Olympus Pro Marketing Co., Ltd.) so that the cut length was approximately 10 mm. The laser beam was a single mode, and a continuous wave with a wavelength of 810 nm was irradiated for 40 ms at an output of 30 W. When the cut surface portion of the hollow fiber was melted and crushed while being cut, the end portion was sealed, and a display unit having polystyrene yarn inside the hollow cylindrical body could be formed.

<Cutting of display element in hollow cylinder>
Next, the polystyrene yarn inside the hollow cylinder was cut using a semiconductor laser UDL-15V without damaging the hollow cylinder. The laser beam was a single mode, and a continuous wave having a wavelength of 810 nm was irradiated at an output of 1 W for 40 ms, whereby the polystyrene yarn was cut to produce a 1 mm long display element.
In this way, a display unit having a plurality of display elements inside could be formed by cutting the polystyrene yarn with a laser.

<Production of display device>
The plurality of display units obtained as described above were formed into a sheet by making a generally uniform web, needling and entangled with a base fabric made of polyester fiber filament yarn. At this time, the thickness of the sheet was about 400 μm.

  Next, a sheet comprising the display unit was sandwiched between transparent electrode plates from above and below to obtain a display device. The electrode plate used was a glass plate deposited with ITO on one side.

<Evaluation of display device>
When a DC power supply is used to apply a positive charge to the upper electrode and a negative charge to the lower electrode to make the voltage difference between the electrodes 200V, most display elements have the white surface as the upper electrode (display surface). Toward. When the direction of the electrode was reversed, most display elements faced the black surface toward the display surface.
Further, the optical image density at this time was measured with a Macbeth densitometer, and the ratio of the image density during black display and the image density during white display was determined as a contrast ratio. 6: 1.
Since it has such a contrast ratio, the image formed by the display device is easy to adjust to the eyes like a printed matter and has no eye fatigue due to external light.

  INDUSTRIAL APPLICABILITY The present invention can be used for manufacturing a display unit that constitutes a light receiving display device, and greatly contributes to the industry.

It is a conceptual diagram of display element preparation by the laser of this invention. It is a schematic diagram which shows an example of the display unit manufactured by the manufacturing method of this invention. It is a schematic diagram which shows an example of the display apparatus provided with the display unit manufactured by the manufacturing method of this invention. It is a cross-sectional schematic diagram which shows the image display state after (a) display apparatus drive in one display unit in a display apparatus, and (b) display apparatus drive. It is a schematic diagram (cross section) of the nozzle | cap | die discharge hole of the extruder used for hollow cylinder preparation in the Example. It is a schematic diagram of a conventionally well-known display apparatus (a) and a display element (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Display unit, 2 ... Hollow cylinder, 3a-3c ... Display element, 4 ... Dielectric liquid, 11 ... Hollow cylinder, 12 ... Display element, 13a-13c ... The cut | disconnected display element, 30 ... Display apparatus, DESCRIPTION OF SYMBOLS 31 ... Display unit, 32 ... Image display part, 33a-33b ... Power supply, 34a-34b ... Wiring, 51 ... Base discharge hole, 52 ... Gas discharge hole, 53 ... Resin discharge hole, 61 ... Display element, 62 ... Base | substrate, 63 ... Air gap, 64 ... Dielectric liquid, 65 ... Display device, 66a-66d ... Electrode, 67a-67b ... Transparent panel, 68a, 68b ... Transparent electrode, 69a, 69b ... Power supply

Claims (5)

A columnar display element that can rotate independently is enclosed in a transparent hollow cylinder, and different color regions for display are divided on the surface of the display element, and the display element Is a method of manufacturing a display unit that is polarized in two differently charged states,
Formation of a hollow cylinder that forms a hollow cylinder in which at least one display element is enclosed by cutting a hollow fiber having at least one display element inside by laser and sealing the cut surface Process,
A display element cutting step of cutting at least one display element enclosed in the hollow cylindrical body into at least two by a laser, and in the hollow cylinder forming step and the display element cutting step, A method of manufacturing a display unit using a laser.   The method of manufacturing a display unit according to claim 1, wherein a semiconductor laser or an yttrium-aluminum-garnet crystal laser is used as the laser. A columnar display element that can rotate independently is enclosed in a transparent hollow cylinder, and different color regions for display are divided on the surface of the display element, and the display element Is a method of manufacturing a display unit that is polarized in two differently charged states,
A display element cutting step of cutting at least one display element enclosed in the hollow cylindrical body into at least two by a laser, and using a semiconductor laser or an yttrium-aluminum-garnet crystal laser as the laser A manufacturing method of a display unit characterized by the above. A columnar display element that can rotate independently is enclosed in a transparent hollow cylinder, and different color regions for display are divided on the surface of the display element, and the display element Is a method of manufacturing a display unit that is polarized in two differently charged states,
Formation of a hollow cylinder that forms a hollow cylinder in which at least one display element is enclosed by cutting a hollow fiber having at least one display element inside by laser and sealing the cut surface A method of manufacturing a display unit, comprising: a step of using a semiconductor laser or a yttrium-aluminum-garnet crystal laser as the laser. The method for manufacturing a display unit according to claim 1, wherein a semiconductor laser is used as the laser.

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