Electrophoretic device, electrophoretic display apparatus, electronic apparatus, and method of manufacturing electrophoretic device

An electrophoretic device includes a fiber layer, an electrophoretic particle configured to migrate through a gap in the fiber layer, and a partition wall extended in a thickness direction of the fiber layer to separate the fiber layer into a plurality of migration cells. The partition wall includes a cured body of a curable resin, and the cured body includes a constriction part between both end portions of the fiber layer in the thickness direction.

BACKGROUND

The present disclosure relates to an electrophoretic device including electrophoretic particles dispersed in a fiber layer, an electrophoretic display apparatus, an electronic apparatus, and a method of manufacturing an electrophoretic device.

In recent years, for mobile apparatuses such as a mobile phone terminal and a personal digital assistant, a display apparatus that displays images with higher quality is being demanded. For example, as a display apparatus of an electronic book terminal for reading, reflective display apparatuses and light-emitting display apparatuses have been proposed. Out of the reflective display apparatuses, a rapid-response electrophoretic display apparatus with low power consumption is expected as a display apparatus for an electronic book terminal.

Electrophoretic display apparatuses disclosed in Japanese Examined Patent Publication No. Sho 50-015115, Japanese Patent Translation Publication No. 2004-526210, Japanese Patent Application Laid-open No. Hei 1-86116, and Japanese Patent Translation Publication No. 2003-526817 cause charge particles of two types having different reflectances from each other to move in different directions by an electrical field. Colors for display which are represented by distributions of the electrophoretic particles of two types are changed depending on a direction or a size of the electrical field. In the electrophoretic display apparatuses disclosed in Japanese Patent Translation Publication No. 2004-526210 and Japanese Patent Application Laid-open No. Hei 1-86116, electrophoretic particles of two types and a solvent are encapsulated in a microcapsule. In the electrophoretic display apparatus disclosed in Japanese Patent Translation Publication No. 2003-526817, electrophoretic particles of two types and a solvent are filled in a microcup which has a lattice-shaped partition wall. With those structures, the aggregation, precipitation, and convection of the electrophoretic particles are suppressed, with the result that unevenness of an image displayed is suppressed.

SUMMARY

Incidentally, in the display apparatuses in which the microcapsule or the microcup is used, the partition wall of the microcapsule or the microcup is exposed to a display surface by an area to the same extent as the electrophoretic particles. Generally, the value of the reflectance of the partition wall is intermediate between the values of the reflectances of the electrophoretic particles of two types. The partition wall makes the display surface darker, with the result that a contrast in the electrophoretic display apparatus becomes lower.

As described above, in the electrophoretic display apparatuses, although various structures mentioned above have been proposed, the contrast in an image displayed is susceptible to improvement.

It is desirable to provide an electrophoretic device, an electrophoretic display apparatus, an electronic apparatus, and a method of manufacturing an electrophoretic device which are capable of increasing the contrast.

According to an embodiment of the present disclosure, there is provided an electrophoretic device including a fiber layer, an electrophoretic particle configured to migrate through a gap in the fiber layer, and a partition wall extended in a thickness direction of the fiber layer to separate the fiber layer into a plurality of migration cells. The partition wall includes a cured body of a curable resin, and the cured body includes a constriction part between both end portions of the fiber layer in the thickness direction.

According to another embodiment of the present disclosure, there is provided a method of manufacturing an electrophoretic device including filling a gap in a stacked fiber that forms a fiber layer with a curable resin, curing the curable resin from both sides of the fiber layer in the thickness direction and forming, in the fiber layer, a partition wall including a constriction part between both end portions in the thickness direction, and causing an electrophoretic particle to be included in the gap in the fiber.

In the electrophoretic device that causes the electrophoretic particle to migrate in the gap in the fiber layer, the width of the partition wall for separating the fiber layer into the plurality of migration cells affects the contrast of an image of the electrophoretic device and the contrast of an image of the electrophoretic display apparatus provided with the electrophoretic device. That is, the larger the width of the partition wall is, the smaller a display area where the optical characteristic changes due to the electrophoretic particle, that is, an aperture ratio becomes. Thus, the optical characteristics such as scatter and refraction of light on the entire display surface are deteriorated. As a result, the contrast on the display surface is deteriorated.

By uniformly thinning the width of the partition wall, the deterioration of the contrast can be suppressed, but in this case, a mechanical strength necessary for the partition wall may be maintained. In particular, the front and back surfaces of the fiber layer which are the both end portions in the thickness direction of the fiber layer are portions susceptible to an external force by stacking another layer, for example. Accordingly, a larger mechanical strength is necessary as compared to the inside of the fiber layer.

In this point, in the electrophoretic device according to the embodiment of the present disclosure, the constriction part is provided between the both end portions of the partition wall in the thickness direction of the fiber layer. With this structure, it is possible to improve the optical characteristics of the fiber layer inside the migration cells while maintaining the mechanical strength necessary for the partition wall. Thus, it is possible to increase the contrast in the electrophoretic device.

By the method of manufacturing the electrophoretic device according to the embodiment of the present disclosure, the resin is cured from the both sides in the thickness direction in the fiber layer. Therefore, it is possible to form the partition wall that penetrates the fiber layer, even if the density of the fiber in the fiber layer is high to such an extent that the curing of the resin from one side in the thickness direction in the fiber layer does not reach the other side in the thickness direction in the fiber layer.

The density of the fiber that forms the fiber layer can be increased, so the optical characteristics held by the fiber can be increased in the fiber layer, with the result that the contrast in the electrophoretic device can be increased.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of an electrophoretic device, an electrophoretic display apparatus, an electronic apparatus, and a method of manufacturing an electrophoretic device in the present disclosure will be described.

(Structure of Electrophoretic Display Apparatus)

As shown inFIG. 1, an electrophoretic display apparatus10is provided with an electrophoretic device30laminated on a substrate20. The substrate20is a laminated body constituted of a support member21and a TFT layer22laminated on an upper surface of the support member21. The electrophoretic device30is a laminated body constituted of an opposed layer31bonded to the TFT layer22, a translucent layer32that faces the opposed layer31, and a fiber layer40sandwiched between the opposed layer31and the translucent layer32.

The support member21is a substrate with a mechanical strength which supports the components of the electrophoretic display apparatus10, and the support member may be a translucent substrate that allows light to pass therethrough or a reflective substrate that reflects light. Further, the support member21may be a substrate having flexibility or a substrate with no flexibility. Whether the support member21has the translucency or the flexibility is appropriately selected in accordance with a use purpose of the electrophoretic display apparatus10.

Examples of a material of the support member21include an inorganic material such as stainless, silicon, silicon oxide, silicon nitride, aluminum oxide, aluminum, nickel, and stainless. Further, for the support member21, a resin material such as polycarbonate, polyethylene terephthalate, polyethylene naphthalate, and polyether ether ketone is used. It should be noted that the support material21may be a single-layer structure or a multilayer structure. A plurality of layers that form the multilayer structure may be formed of the same material or different materials from each layer.

The TFT layer22is a multilayer structure for driving the electrophoretic display apparatus10, and the TFT layer may be a layer directly formed on the support member21or a layer bonded to the support member21. The TFT layer22is provided with a plurality of thin film transistors that are drive devices for electrophorese the electrophoretic particles, an insulating layer24that covers the thin film transistors23, and a plurality of pixel electrodes25that are connected to the thin film transistors23with the insulating layer24intervened therebetween. In the example shown in the figure, the thin film transistors23are formed on the support member21.

The thin film transistor23may be an inorganic transistor in which an inorganic semiconductor such as amorphous silicon and polysilicon is used for an active layer or may be an organic transistor in which an organic semiconductor layer of polythiophene, pentacene or the like is used for an active layer. The pixel electrode25is formed of a metal oxide such as gold, silver, copper, aluminum, an aluminum alloy, and an indium tin oxide. The pixel electrode25may be a translucent electrode that allows light to pass therethrough or a reflective electrode that reflects light. Whether the pixel electrode25has translucency or not is appropriately determined in accordance with a use purpose of the electrophoretic display apparatus10as in the case of the support member21.

The opposed layer31is a film structure that protects the pixel electrodes25against a mechanical contact or chemical erosion and is bonded to an upper surface of the TFT layer22. Further, the opposed layer31has a sealing property such that the electrophoretic particles and a liquid contained in the fiber layer40are sealed in the fiber layer40and is bonded to a lower surface of the fiber layer40. For example, the opposed layer31may be a thin film laminated on the TFT layer22or a film member that is bonded to the fiber layer40.

The opposed layer31is formed of a resin material such as a phenol resin, an epoxy resin, and a polyimide resin. Further, the opposed layer31is formed of an inorganic material such as a silicon oxide, a silicon nitride, and silicon oxynitride. It should be noted that the opposed layer31may have a single-layer structure or a multilayer structure. A plurality of layers that form the multilayer structure may be formed of the same material or different materials from each layer.

The translucent layer32is a sheet member having translucency such that light from the outside of the electrophoretic display apparatus10is allowed to reach the fiber layer40and a sealing property such that the electrophoretic particles and a liquid contained in the fiber layer40are sealed in the fiber layer40, and is bonded to the upper surface of the fiber layer40. In the translucent layer32, on an entire lower surface of an insulating sheet33that allows light to pass therethrough, a transparent electrode34that forms an electrical field between the pixel electrodes25and the transparent electrode34is laminated.

Examples of a material of the insulating sheet33include a silicon oxide, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyether ether ketone, or the like. The transparent electrode34is made of a conductive material having translucency such as an indium tin oxide, an antimony tin oxide, a fluorine-added tin oxide, and an aluminum-added zinc oxide.

As shown inFIG. 2, the fiber layer40is a structure including fibers41stacked and is sandwiched between the opposed layer31and the translucent layer32. The fiber layer40may be a structure in which one fiber41is folded or a structure in which a large number of fibers41are overlapped. Further, the fiber layer40may have a multilayer form in which layers having a large number of fibers41disposed with gaps are regularly overlapped or may have a porous form in which a large number of fibers41are irregularly disposed. In the fiber layer40, a partition wall43that penetrates the fiber layer40in a thickness direction is formed. The thickness direction of the fiber layer40is set as a direction in which a plurality of layers including the fiber layer40are stacked. For example, in the thickness direction, the fiber layer40is stacked on the translucent layer, and the opposed layer31is stacked on the fiber layer40. By separating the fiber layer40into migration cells, namely cells C (see,FIG. 4), for the electrophoretic particles44, the partition wall43partitions the fiber layers40into the cells C. In the partition wall43, a part of the fiber41is buried.FIG. 2shows the fibers41including a part inside the partition wall which is buried in the partition wall43and a part outside the partition wall which is disposed in the migration cell. In a part (cell C inFIG. 4) obtained by removing the fibers41and the partition wall43from the fiber layer40, a dispersion medium45which is an insulating liquid is filled. In the dispersion medium45, the electrophoretic particles44that electrophorese in the gaps between the fibers41are dispersed. In this way, the fiber layer40is sandwiched by the opposed layer31with the insulating dispersion medium45.

As shown inFIG. 3, the fiber41is a line material having a sufficiently large length relative to a diameter thereof. In the fiber41, non-electrophoretic particles42are held while being dispersed. The non-electrophoretic particles42are particles that are not electrophoresed by an electrical field and have an optical characteristic on which color indicated by the fiber layer40depends.

For example, in the case where the non-electrophoretic particles42have such a characteristic as to reflect visible light in an entire band, by the reflection of the non-electrophoretic particles42, the fiber layer40indicates white color. Further, for example, in the case where the non-electrophoretic particles42have such a characteristic as to reflect visible light except blue, by the reflection of the non-electrophoretic particles42, the fiber layer40indicates yellow. Furthermore, for example, in the case where the non-electrophoretic particles42have such a characteristic as to convert visible light into a fluorescent color, by the color conversion of the non-electrophoretic particles42, the fiber layer40indicates the fluorescent color. Furthermore, for example, in the case where the non-electrophoretic particles42have such a characteristic that light interferes depending on the structure or arrangement of the non-electrophoretic particles42, by the interference of light by the non-electrophoretic particles42, the fiber layer40indicates a structural color.

It should be noted that in the case where the non-electrophoretic particles42have such an optical characteristic as to reflect light having a predetermined wavelength, it is desirable that the non-electrophoretic particles42adjacent to each other are disposed at a shorter interval L than the wavelength of visible light. If a large number of non-electrophoretic particles42are disposed at the intervals L, in the fiber layer40, the non-electrophoretic particles42are disposed at an interval equal to or shorter than the interval L. As a result, the interference of light is suppressed between the non-electrophoretic particles42adjacent to each other, so the reflection of light by the non-electrophoretic particles42is increased, and therefore the intensity of the color indicated by the fiber layer40is increased.

The fiber41may be a linear line material, a winding line material, or a line material branched into two or more. Out of those configurations, if the fiber41is the winding line material, the fibers41are complicatedly intertwined, and the internal structure of the fiber layer40becomes complicated, with the result that the optical characteristic of the fiber layer40is improved. It should be noted that in the fiber41, the non-electrophoretic particles42are buried, so a main line material that forms the fiber41may be a resin that allows light to pass therethrough in the dispersion medium45or may be a resin that makes up for the optical characteristic of the non-electrophoretic particles42. That is, the optical characteristic of the fiber layer40depends on the non-electrophoretic particles42, so the main line material in the fiber41is selected as appropriate within a range in which the optical characteristic of the non-electrophoretic particles42is reflected on the fiber layer40itself. Further, in the case where the main line material that forms the fiber41has a high responsiveness to the dispersion medium45, the surface of the main line material that forms the fiber41is desirably covered by an additional protection layer. In the case where the main line material that forms the fiber41has an optical characteristic on which the color indicated by the fiber layer40depends, the non-electrophoretic particles42described above may be excluded.

The diameter of the fiber41is selected as appropriate in accordance with the size of the electrophoretic particle44. For example, the diameter of the fiber41is set to be small to such an extent that the electrophoretic particle44is not exposed from a gap between the fibers41stacked by disposing a lower fiber41in a gap between the fibers41. Further, the diameter of the fiber41the size of the non-electrophoretic particle42and is set to be large to such an extent that the non-electrophoretic particle42is buried in the fiber41. For example, it is desirable that the diameter of the fiber41is 0.001 μm to 10 μm (both inclusive). In particular, if a nanofiber, the diameter of which is 0.001 μm to 0.1 μm (both inclusive), and the length of which is 100 times larger than the diameter thereof or more, is the fiber41, a gap between the fibers41is larger, so the electrophoretic particle44is easily electrophoresed in such a gap. Further, the internal structure of the fiber41becomes complicated, so the optical characteristic of the fiber layer40is improved by the structure of the fiber layer40. It should be noted that the thickness of the fiber40is selected as appropriate in accordance with responsiveness and a contrast demanded for a display image of the electrophoretic display apparatus10, for example, 5 μm to 10 μm.

As a main line material that forms the fiber41, for example, a resin material such as nylon, polylactate, polyamide, polyimide, polyethylene terephthalate, polyacrylonitrile, polyethylene oxide, polyvinyl carbazole, and polyvinyl chloride is used. It should be noted that it is also possible to use a resin material such as polyurethane, polystyrene, polyvinyl alcohol, polysulfone, polyvinyl pyrrolidone, polyvinylidene fluoride, and poly hexafluoropropylene for the material of the line material in the fiber41. Further, for the fiber41, a polymer material such as cellulose acetate, collagen, gelatin, and chitosan can also be used. It should be noted that a copolymer of those resin materials and polymer materials can also be used for the fiber41. Examples of a method of forming the fiber41include an electrostatic spinning method, a phase separation method, a phase inversion method, a melt spinning method, a wet spinning method, a dry spinning method, a gel spinning method, a sol-gel method, a spray coating method, and the like.

The electrophoretic particle44is a charged particle that is electrophoresed by an electrical field formed between the pixel electrodes25and the transparent electrode34, and is sufficiently small relative to the gap between the fibers41included in the fiber layer40. The electrophoretic particles44may be one kind of charged particles or two or more kinds of charged particles the optical characteristics of which are different from each other. It should be noted that in the case where the electrophoretic display apparatus10displays an image with a density difference of the same color or with a brightness difference of the same color, the optical characteristics of the electrophoretic particles44may be the same as the non-electrophoretic particles42.

For the electrophoretic particle44, as an organic pigment, a polycyclic pigment such as a quinacridone series pigment and a quinophthalone series pigment, an azo series pigment such as β-naphthol series pigment and a pyrazolone series pigment, a daylight fluorescent pigment, or a hollow resin pigment is used, for example. Further, for the electrophoretic particle44, as an inorganic pigment, a black pigment such as carbon black and bone black, a white pigment such as barium sulfate and a silicon oxide, or an inorganic fluorescent pigment such as a sulfide and silicate is used, for example. Furthermore, for the electrophoretic particle44, as a dye, an organic dye such as an azo series dye and a phthalocyanine series dye or an organic fluorescent dye such as a diaminostilbene series dye is used, for example. For the electrophoretic particle44, as a metal material, gold, silver, copper, or the like is used, for example. As a metal oxide, a titanium oxide, a zinc oxide, a zirconium oxide, or the like is used, for example. It should be noted that on a surface of the electrophoretic particle44, a surfactant treatment or a coupling agent treatment for improving dispersiveness of the electrophoretic particles44may be performed.

The dispersion medium45is an insulating liquid capable of electrophoresing the electrophoretic particles44. To increase the mobility of the electrophoretic particles44and suppress power necessary for moving the electrophoretic particles44, it is desirable that the dispersion medium45is a liquid having a low viscosity. Further, the dispersion medium45may be one kind of liquid or a liquid obtained by mixing two or more kinds of liquids. Furthermore, the dispersion medium45may contain at least one of a colorant, a charge control agent, a dispersion stabilizer, a viscosity modifier, and a surfactant. It should be noted that in the case where reflection of light having a predetermined wavelength is provided as the optical characteristic of the fiber41, it is desirable that the refractive index of the dispersion medium45is different from that of the fiber41and the non-electrophoretic particle43to a large extent.

For the dispersion medium45, for example, an insulating organic medium such as aliphatic hydrocarbon, aromatic hydrocarbon, halogenated hydrocarbon, and silicone oil is used. More specifically, for the aliphatic hydrocarbon, pentane, hexane, cyclohexane, heptane, octane, nonane, deacne, dodecane, ligroin, solvent naphtha, kerosene, normal paraffin, isoparaffin, or the like is used.

Further, for the aromatic hydrocarbon, benzene, toluene, xylene, alkyl benzene, or the like is used.

As shown inFIG. 4, the partition wall43is a cured resin member (cured body) extended in the thickness direction of the fiber layer40and having a hexagonal tubular surface shape, and has so-called a honeycomb structure obtained by arrangement with no gap in the entire translucent layer32. The partition wall43may have a lattice shape. Between the opposed layer31and the translucent layer32, a large number of cells C, each of which is a space surrounded by the partition wall43and has a hexagonal tubular shape, are formed. In the cells C, the fibers41, the electrophoretic particles44, and the dispersion medium45are contained.

The partition wall43that fills the gap between the fibers41in the thickness direction is formed of a curable resin. Therefore, the resin to be cured which fills the gap between the fibers41is cured in the thickness direction of the fiber layer40, with the result that it is possible to form the partition wall43having a complicated shape to fill the gap between the fibers41. Further, a part of the fiber41is buried in the partition wall43, so the optical characteristic of the fiber41works not only in the centers of the cells C but in the boundary between the cells C and the partition wall43. It should be noted that the partition wall43may be made of only the curable resin or may be made of a material equipped with the same optical characteristic as the fiber41in addition to the curable resin.

As shown inFIG. 5, the partition wall43is constituted of a trapezoidal first part43awhich is in contact with the transparent electrode34of the translucent layer32and is extended along the lower surface of the transparent electrode34and a trapezoidal second part43bwhich is in contact with the opposed layer31and is extended along the upper surface of the opposed layer31.

The first part43ais a part which is tapered from the translucent layer32toward the opposed layer31and the width of which is monotonously decreased from the translucent layer32toward the opposed layer31. On the other hand, the second part43bis a part which is tapered from the opposed layer31toward the translucent layer32and the width of which is monotonously decreased from the opposed layer31toward the translucent layer32. Therefore, on a connection part43cwith the first part43aand the second part43b, a constriction part of the partition wall43is formed. The constriction part is a part of the partition wall43between the opposed layer31and the transparent electrode34, and at the part, the width of the partition wall43is increased toward the opposed layer31and increased toward the translucent layer32.

In the electrophoretic device30that electrophoreses the electrophoretic particles44in the gap between the fibers41in the fiber layer40, the width of the partition wall43for separating the fiber layer40into the plurality of cells C affects a contrast of an image of the electrophoretic device30and a contrast of an image of the electrophoretic display apparatus10provided with the electrophoretic device30. The larger the width of the partition wall is, the less the fiber layer40contained in the cells C becomes. Therefore, the optical characteristics such as the scatter and refraction of light in the fiber layer40are lowered on the display surface. As a result, the contrast on the display surface is lowered.

By uniformly thinning the width of the partition wall43, it is possible to suppress the contrast from being lowered, but in this case, the mechanical strength necessary for the partition wall43may be maintained. In particular, the front surface and the back surface of the fiber layer40, which are both end portions of the fiber layer40in the thickness direction, are parts where an external force is likely to act by stacking the translucent layer32and the opposed layer31, for example. Therefore, the necessary mechanical strength is higher as compared to the inside of the fiber layer40.

In the electrophoretic device30, in the partition wall43, between the both end portions of the fiber layer40in the thickness direction, the constriction part is provided. With this structure, it is possible to improve the optical characteristics of the fiber layer40in the cells C while maintaining the mechanical strength necessary for the partition wall43. As a result, it is possible to increase the contrast in the electrophoretic device30.

Generally, a cured quantity in the curable resin is the largest at a part that directly receives energy necessary for the curing. Along with the transmission of the energy for curing, the cured quantity in the curable resin becomes small. In the structure of the partition wall43, the connection part43cis a transmission destination of the energy for the curing. Further, the both end portions in the partition wall43in the thickness direction are parts that directly receive the energy for the curing. In other words, to the resin before being cured which fills the gap between the fibers41, the energy necessary for the curing of the resin is supplied from the both sides in the thickness direction in the fiber layer40. As a result, even if the density of the fibers41is high to such an extent that the curing from one side in the fiber layer40in the thickness direction does not reach to the other side in the fiber layer40in the thickness direction, it is possible to form the partition wall43that penetrates the fiber layer40. In the case where the optical characteristics of the fiber41prevent the energy necessary for the curing of the resin from being transmitted, the effect described above becomes more noticeable.

Here, a thickness from the contact portion between the first part43aand the transparent electrode34to the connection part43cis set to a first part thickness H1, and a thickness from a contact portion between the second part43band the opposed layer31to the connection part43cis set to a second part thickness H2. Further, in a width direction perpendicular to the thickness direction of the fiber layer40, a width of the contact part between the first part43aand the transparent electrode34is set to a first part width W1, and a width of the contact part between the second part43band the opposed layer31is set to a second part width W2.

In the above-mentioned structure of the partition wall43, the first part thickness H1is thinned than the second part thickness H2, and the first part width W1is smaller than the second part width W2. In addition, the ration between the first part thickness H1and the first part width W1is substantially equal to the ratio between the second part thickness H2and the second part width W2. Thus, the connection part43cof the first part43aand the second part43bis formed to be closer to the transparent electrode34relative to the opposed layer31in the thickness direction of the fiber layer40.

In the first place, the partition wall43is used to suppress the electrophoretic particles44from moving between the adjacent cells C, so the both end portions in the partition wall43in the thickness direction are necessary to be in contact with the opposed layer31and the transparent electrode34. Therefore, if a part of the fiber41is included in the partition wall43, the partition wall43having the structure described above impedes the optical operation of the fiber41, unless the partition wall43makes up for the optical characteristics of the fiber41. For example, the contact part between the first part43aand the transparent electrode34impedes the optical operation of the fiber41through the translucent layer32.

In this point, by the partition wall43having the structure described above, a contact area of the partition wall43and the transparent electrode34naturally becomes smaller than a contact area of the partition wall43and the opposed layer31. Therefore, as compared to the structure in which the first part width W1is more than the second part width W2, an image of the partition wall43which is formed through the translucent layer32is smaller. As a result, an image of the electrophoretic particle44which is formed through the translucent layer32becomes larger.

At the time when the partition wall43is formed, one of the opposed layer31and the translucent layer32supports the partition wall43. With the partition wall43having the structure described above, the contact area between the partition wall43and the opposed layer31is larger than the contact area with the translucent layer32in the partition wall43. That is, of the opposed layer31and the translucent layer, with one where an image of the electrophoretic particle44is not formed outside, the contact area of the partition wall43becomes large. Therefore, by supporting the partition wall43by the opposed layer31, it is possible to make an image of the electrophoretic particle44relatively large and secure the support structure to support the partition wall43at the same time.

For the material of the partition wall43, for example, a light-curable resin which is cured by receiving light having a predetermined wavelength or a thermosetting resin that is hardened by receiving heat is used. Examples of the light-curable resin include a photo crosslinking reaction type, a photo modification type, a photo polymerization reaction type, a photo degradation reaction type, and the like. Further, as the light curable resin, a UV-curable resin such as a UV-curable resin mainly containing an acrylic compound, a UV-curable resin mainly containing a urethane acrylate oligomer, and a vinylphenol-based resin is used. As the thermosetting resin, for example, a phenol resin, an epoxy resin, or an ester resin may be used.

(Operation of Electrophoretic Display Apparatus)

Next, the operation of the electrophoretic display apparatus10will be described. It should be noted that, in the explanation of the operation, the fiber41has such an optical characteristic as to reflect visible light in an entire band, and the electrophoretic particles44have such an optical characteristic as to absorb visible light in the entire band and are charged particles of one kind which are positively charged. A white image is formed through the translucent layer32by the fiber layer40, and a black image is formed through the translucent layer32by the electrophoretic particle44.

In an initial state of the electrophoretic display apparatus, a negative voltage with respect to the transparent electrode34is applied to all the pixel electrodes25. In response to the application of the voltage, all the electrophoretic particles44are moved toward the opposed layer31. The visible light that enters the fiber layer40through the translucent layer32is reflected by the fibers41stacked. As a result, outside the translucent layer32, a white solid color image is displayed.

From the initial state, when a drive circuit supplies a drive signal to the thin film transistors23in accordance with the display image, the pixel electrode25is selected through the drive of the thin film transistors23, and a positive voltage with respect to the transparent electrode34is applied to the pixel electrode selected. In response to the application of the voltage, the electrophoretic particles44between the pixel electrode25selected and the transparent electrode are moved toward the transparent electrode34. Then, the light that has passed through the translucent layer32is absorbed by the electrophoretic particles44at such a position to face the pixel electrode25selected. As a result, outside the translucent layer32, a black image corresponding to the arrangement of the pixel electrodes25selected is displayed.

Next, a method of manufacturing the electrophoretic device will be described.

As shown inFIG. 6, first, the transparent electrode34is formed on one entire side surface of the insulating sheet33. Next, by the electrostatic spinning method that uses a polymer material or resin in which the non-electrophoretic particles42are dispersed, the fiber41is discharged from a nozzle51toward the transparent electrode34, thereby stacking the fibers41on the transparent electrode34. It should be noted that, as the method of forming the fiber41, in addition to the electrostatic spinning method, the phase separation method, the phase inversion method, the melt spinning method, the wet spinning method, the dry spinning method, the gel spinning method, the sol-gel method, the spray coating method, or the like is used.

As shown inFIG. 7, to the fiber41stacked on the transparent electrode34, a liquid curable resin53is applied, and the curable resin53fills the gap of the fiber41. It should be noted that at this time, the curable resin53applied to the transparent electrode34is held on the transparent electrode34with a frame-shaped sealing member that surrounds the outer periphery of the insulating sheet33. After that, a cure-purpose substrate52which allows energy for curing the curable resin53to pass therethrough is put on the liquid surface of the curable resin53, and the fiber41and the curable resin53are sealed between the translucent layer32and the cure-purpose substrate52with the sealing member. At this time, to the cure-purpose substrate52, a pressure force is applied to such an extent that a distance H3between the cure-purpose substrate52and the insulating sheet33is uniform for the entire cure-purpose substrate52. By performing sealing with the cure-purpose substrate52described above, it is possible to suppress a content of the curable resin53that is filled in the fiber layer40and the thickness of the fiber layer40from varying depending on the electrophoretic devices30. Further, it is also possible to suppress an inner pressure of the fiber layer40in which the curable resin53is filled from varying depending on the electrophoretic devices30.

As shown inFIG. 8, the energy that cures the curable resin53is supplied to the curable resin53through both the cure-purpose substrate52and the translucent layer32. It should be noted that, as long as the curing energy that passes through the translucent layer32and the curing energy that passes through the cure-purpose substrate52may be supplied to parts that face each other at a predetermined time, the energies may be supplied at the same time or at different timings.

For example, in the case here the curable resin53is a UV-curable resin, the curing resin53is irradiated with a first UV ray54that passes through the translucent layer32, and the curable resin53is irradiated with a second UV ray55that passes through the cure-purpose substrate52. At this time, through an optical system in which an interface between the translucent layer32and the curable resin53serves as a focal plane, the curable resin53is irradiated with the first UV ray54. Further, through an optical system in which an interface between the cure-purpose substrate52and the curable resin53serves as a focal plane, the curable resin53is irradiated with the second UV ray55. It should be noted that the amount of energy supplied to the curable resin53through the translucent layer32is smaller than the amount of energy supplied to the curable resin53through the cure-purpose substrate52. For example, the size of a light cross-section formed on the translucent layer32by the first UV ray54is equal to the size of a light cross-section formed on the cure-purpose substrate52by the second UV ray55, and the intensity of the second UV ray55is larger than the intensity of the first UV ray54.

For the irradiation with the first UV ray54and the second UV ray55, a UV laser for forming a predetermined light cross-section may be used as a light source. Alternatively, for the irradiation with the first UV ray54and the second UV ray55, a mask having an opening for forming the predetermined light cross-section on the translucent layer32or the cure-purpose substrate52and a UV lamp for irradiating the entire surface of the translucent layer32or the cure-purpose substrate52with the UV ray may be used. The method of using the UV laser is excellent in making miniaturization of the light cross-section easy, and the method of using the UV lamp or the mask is excellent in making the increase of the area of the light cross-section easy. It should be noted that both the UV laser and the mask may be used.

Then, as shown in the right part ofFIG. 8, from a part that receives the energy for the curing, the curing progresses in a direction in which the energy is transmitted at a speed in accordance with the amount of energy. For example, in the curable resin53which is irradiated with the first UV ray54and the second UV ray55, from a part that receives the UV ray, the curing progresses in a direction in which the UV ray is transmitted.

At this time, the fiber41contained in the curable resin53prevents the transmission of the energy for the curing. Therefore, the energy for the curing that is received by the curable resin53is gradually weakened toward the center of the fiber layer40in the thickness direction. For example, as the first UV ray54goes from the translucent layer32toward the cure-purpose substrate52, the light quantity of the first UV ray54dispersed in the fiber41increases, and as the second UV ray55goes from the cure-purpose substrate52toward the translucent layer32, the light quantity of the second UV ray55dispersed in the fiber41increases. The first UV ray54that is received by the curable resin53and the second UV ray55that is received by the curable resin53are gradually weakened toward the center of the fiber layer40in the thickness direction. As a result, from the interface between the translucent layer32and the curable resin53, the first part43athat is tapered toward the cure-purpose substrate52, and from the interface between the cure-purpose substrate52and the curable resin53, the second part43bthat is tapered toward the translucent layer32.

As shown in the left part ofFIG. 8, in a part where the energy for the curing is relatively weak, the trapezoidal first part43awhich is relatively small is formed, and in a part where the energy for the curing is relatively strong, the trapezoidal second part43bwhich is relatively large is formed. As a result, between the both end portions in the fiber layer40in the thickness direction, the connection part43cwhere the first part43aand the second part43bare connected with each other is formed in a position close to the translucent layer32, for example. The connection part43cis an example of the constriction part of the partition wall43.

It should be noted that, as the curable resin53to be cured is thicker, the energy necessary for the curing is increased at a geometric rate. In the case where the energy for the curing is supplied from the both surfaces of the fiber layer40, the amount of energy increased is divided into the translucent layer32side with respect to the curable resin53and the cure-purpose substrate52side with respect to the curable resin53. Therefore, as compared to the case where the energy for the curing is supplied from only one of the translucent layer32and the cure-purpose substrate52, the amount of energy necessary for curing the curable resin53can be suppressed.

As shown inFIG. 9, after the energy for the curing is supplied, the curable resin53that is not cured is cleaned. That is, after the cure-purpose substrate52is removed from the fiber layer40, the curable resin53that is not cured is washed away from the translucent layer32. At this time, for the washing of the curable resin53, a detergent solution that dissolves the curable resin53and does not dissolve the partition wall43and the fiber41is used. After the cleaning of the curable resin53, in the fiber layer40, the partition wall43that penetrates the fiber layer40is formed in a direction in which the fiber is stacked. Then, the dispersion medium45in which the electrophoretic particles44are dispersed is filled in the cells C. After that, in the fiber layer40, the support member21provided with the TFT layer22and the opposed layer31are laminated. As a result, the electrophoretic display apparatus10shown inFIG. 1is manufactured.

Example

As the transparent electrode34, an indium tin oxide was used, and the fiber layer40having the thickness of 10 μm to 100 μm was formed on the transparent electrode34. Then, a UV-curable resin was used as the curable resin53, and the fiber layer40was filled with the curable resin53. Subsequently, a glass substrate was used as the cure-purpose substrate52, and the cure-purpose substrate52was placed on the UV-curable resin.

Further, a UV laser was used as the first UV ray54, and the UV-curable resin was irradiated with the UV laser through an optical system in which an interface between the transparent electrode34and the resin serves as a focal plane. At the same time, a UV laser was used as the second UV ray55, and a position that faces the position irradiated with the first UV ray54was irradiated with the UV laser through an optical system in which an interface between the cure-purpose substrate52and the resin serves as a focal plane. At this time, the intensity of the UV laser with which the translucent layer32is irradiated was set to be equal to the intensity of the UV laser with which the cure-purpose substrate52is irradiated.

FIGS. 10A and 10Beach show a plane structure of the partition wall43obtained by the UV laser irradiation, andFIG. 11shows a cross-sectional structure of the partition wall43. It should be noted thatFIG. 10Ais a trace of a stereomicroscope photograph showing a plane structure of the partition wall43shot through the translucent layer32, andFIG. 10Bis a trace of a stereomicroscope photograph showing a plane structure of the partition wall43shot through the cure-purpose substrate52. Further,FIG. 11is a trace of an SEM photograph showing a cross-section of the partition wall43.

As shown inFIG. 10A, the first part width W1of the partition wall43that forms a honeycomb structure was 5 μm to 25 μm. On the other hand, as shown inFIG. 10B, the second part width W2of the partition wall43was 5 μm to 25 μm. It was confirmed that the first part width W1and the second part width W2in the partition wall43was substantially the same.

As shown inFIG. 11, it was confirmed that in the partition wall43, the first part43atapered toward the center in the fiber layer40in the thickness direction and the second part43btapered toward the center in the fiber layer40in the thickness direction were formed. By irradiating the UV-curable resin with the UV laser from the both sides of the fiber layer40, it was confirmed that the partition wall that penetrates the fiber layer40in the thickness direction thereof and confirmed that the part where the first part43aand the second part43bare connected has a constriction shape.

It should be noted that, as another example in which the UV laser is not used, the irradiation with the UV ray was performed in the following process. That is, the transparent electrode was placed on a mask, and the mask was placed on the cure-purpose substrate52. After that, the entire surface of the transparent electrode34was irradiated with the UV ray as the first UV ray54. At the same time, the entire surface of the cure-purpose substrate52was irradiated with the UV ray as the second UV ray. At this time, the intensity of the UV ray with which the translucent layer32is irradiated was set to be equal to the intensity of the UV ray with which the cure-purpose substrate52was irradiated. According to this example, the result similar to the example in which the UV laser was used was confirmed.

Comparative Example

As in the above example, as the transparent electrode34, the indium tin oxide was used, and the fiber layer40having the thickness of 10 μm to 100 μm was formed on the transparent electrode34. Then, a UV-curable resin was used as the curable resin53, and the fiber layer40was filled with the curable resin53. Subsequently, a glass substrate was used as the cure-purpose substrate52, and the cure-purpose substrate52was placed on the UV-curable resin.

Further, the UV-curable resin was irradiated with the UV laser through an optical system in which an interface between the translucent layer32and the UV-curable resin serves as a focal plane. At this time, the intensity of the UV laser was set to be equal to the sum of the intensity of the first UV ray54and the intensity of the second UV ray55in the above example.

FIGS. 12A and 12Beach show a plane structure of the partition wall43obtained by the irradiation with the UV laser.FIG. 12Ais a trace of a stereomicroscopic photograph showing a plane structure of the partition wall43shot through the translucent layer32, andFIG. 12Bis a trace of a stereomicroscopic photograph showing a plane structure of the partition wall43shot through the cure-purpose substrate52.

As shown inFIG. 12A, the first part width W1of the partition wall43having the honeycomb structure was 45 μm to 70 μm. On the other hand, as shown inFIG. 12B, the partition wall43in contact with the cure-purpose substrate52was not confirmed. It was confirmed that the partition wall43does not penetrate the fiber layer40.

It should be noted that, even in the case where only the interface between the translucent layer32and the curable resin53is irradiated with the UV laser, by increasing the intensity of the UV laser, the partition wall43that penetrates the fiber layer40in the thickness direction thereof can be formed. Alternatively, even in the case where the entire surface of the translucent layer32is irradiated with the UV ray through the mask, by increasing the intensity of the UV ray, the partition wall43that penetrates the fiber layer40in the thickness direction thereof can be formed.

However, because the first part width W1of the partition wall in the comparative example is larger than the first part width W1and the second part width W2in the example, the width of the partition wall43is further increased in the case where the irradiation with the UV ray having the intensity mentioned above is performed. As a result of increasing the contact area with the partition wall43in the translucent layer32, it becomes difficult to visually confirm an image of the electrophoretic particles44due to an image of the partition wall43.

Incidentally, even in the case where only the interface between the cure-purpose substrate52and the curable resin53is irradiated with the UV laser, by increasing the intensity of the UV laser, the partition wall43that penetrates the fiber layer40in the thickness direction thereof can be formed. Alternatively, even in the case where the entire surface of the cure-purpose substrate52is irradiated with the UV ray through the mask, by increasing the intensity of the UV ray, the partition wall43that penetrates the fiber layer40in the thickness direction thereof can be formed. However, as a result of increasing the contact area between the opposed layer31and the partition wall43, a voltage applied to the pixel electrodes25is difficult to act on the electrophoretic particles44.

As described above, according to the above embodiment, it is possible to obtain the following effects.

The partition wall43formed of the curable resin has the constriction part between the both end parts of the fiber layer40in the thickness direction. The shape of the partition wall43can be formed by curing the curable resin from the both sides in the thickness direction. For example, even in the case where the density of the fiber41in the fiber layer40is increased, it is possible to form the partition wall43that penetrates the fiber layer40in the thickness direction. As a result of improving the optical characteristic of the fiber layer40, the contrast in the electrophoretic device30is increased.

Because the light-curable resin can be used as a material of the partition wall43, it is possible to make the structure of the partition wall43miniaturized or complicated as compared to the case where a thermo-setting resin is used as a material of the partition wall43.

The connection part43cof the first part43aand the second part43bis formed to be closer to the transparent electrode34as compared to the opposed layer31in the thickness direction of the fiber layer40. Therefore, if the curing energy for forming the first part43aand the curing energy for forming the second part43bare the same, it is possible to make the first part width W1smaller than the second part width W2. As a result, it is easy to make the first part width W1smaller than the second part width W2.

The contact area between the partition wall43and the translucent layer32is smaller than the contact area between the partition wall43and the opposed layer31. Thus, the image of the partition wall43can be difficult to be visually confirmed, and the support structure that supports the partition wall43can be ensured.

As compared to the case where the energy for the curing is supplied only to one side surface of the fiber layer40in the thickness direction thereof, it is possible to form the partition wall43with a smaller amount of energy.

The energy supplied through the translucent layer32is dispersed in the fiber41as approaching the cure-purpose substrate52from the translucent layer32. Further, the width of the first part43ais monotonously decreased toward the cure-purpose substrate52from the translucent layer32in accordance with a change in amount of energy. Thus, it is possible to form the first part43awithout particularly changing the amount of energy supplied through the translucent layer32in the process of the supply.

The energy supplied through the cure-purpose substrate52is disposed in the fiber41as approaching the translucent layer32from the cure-purpose substrate52. Further, the width of the second part43bis monotonously decreased toward the translucent layer32from the cure-purpose substrate52in accordance with a change in amount of energy. Thus, it is possible to form the second part43bwithout particularly changing the amount of energy supplied through the cure-purpose substrate52in the process of the supply.

The interval between the non-electrophoretic particles contained in the fiber41is the predetermined interval L shorter than a wavelength of visible light, so it is possible to suppress interference of light between the non-electrophoretic particles42adjacent to each other.

The first width W1of the first part43ais the largest at the contact part between the first part43aand the translucent layer32, and the second width W2of the second part43bis the largest at the contact part between the second part43band the opposed layer31. The structures of the first part43aand the second part43bcan increase adhesion between the partition wall43and the translucent layer32as compared to the structure in which the constriction part is provided at the contact part between the partition wall43and the translucent layer32. Further, the structures of the first part43aand the second part43bcan increase adhesion between the partition wall43and the opposed layer31as compared to the structure in which the constriction part is provided at the contact part between the partition wall43and the opposed layer31.

The first part width W1of the first part43ais tapered toward the connection part43cas the constriction part from the translucent layer32. Further, the second part width W2of the second part43bis tapered toward the connection part43cas the constriction part from the opposed layer31. Therefore, the more fiber layer40is contained in the cells C as compared to the structure in which the first part width W1and the second part width W2are the same width up to substantially the center between the both end portions of the fiber layer40in the thickness direction. Thus, the optical characteristics such as the scatter and the refraction of light in the cells C are improved on the display surface, with the result that the contrast on the display surface is increased.

Hereinafter, modified examples of the electrophoretic device will be described. It should be noted that, in the modified examples of the electrophoretic device, the shape of a partition wall is different from that in the above embodiment. In the following, the shape of the partition wall in the modified examples will be described in detail. It should be noted that inFIGS. 13 to 17, the pixel electrodes are not shown.

In a first modified example, as shown inFIG. 13, a partition wall46is constituted of a first part46athat is tapered from the translucent layer32toward the opposed layer31and a second part46bthat is tapered from the opposed layer31toward the translucent layer32.

A first part thickness H1of the first part46ais substantially the same as a second part thickness H2of the second part46b. That is, a connection part46cof the first part46aand the second part46bis formed substantially the center between the both end portions of the partition wall46in the thickness direction. The connection part46cis a constriction part of the partition wall46.

The first part width W1of the first part46ais substantially the same as the second part width W2of the second part46b. That is, the contact area of the partition wall46and the opposed layer31is substantially the same as the contact area of the partition wall46and the translucent layer32. In this way, the first part46aand the second part46bof the partition wall46are symmetrical with respect to a plane including the connection part46cin the first modified example.

According to the first modified example, the following effect can be obtained.

The first part46aand the second part46bare symmetrical with respect to the plane, so it is possible to make the amount of energy supplied through the translucent layer32and the amount of energy supplied through the cure-purpose substrate52substantially equal to each other. Thus, it is possible to share the supply source of the energy supplied through the translucent layer32and the energy supplied through the cure-purpose substrate52.

In a second modified example, as shown inFIG. 14, a partition wall47is constituted of a first part47athat is tapered from the translucent layer32toward the opposed layer31and a second part47bthat is tapered from the opposed layer31toward the translucent layer32.

The first part thickness H1of the first part47ais larger than the second part thickness H2of the second part47b. That is, a connection part47cof the first part47aand the second part47bis formed to be closer to the opposed layer31than to the center between the both end portions of the partition wall47in the thickness direction. The connection part47cis a constriction part of the partition wall47.

The first part width W1of the first part47ais larger than the second part width W2of the second part47b. That is, the contact area of the partition wall47and the translucent layer32is larger than the contact area of the partition wall47and the opposed layer31.

According to the second modified example, the following effect can be obtained.

Although the first part width W1is larger than the second part width W2, the partition wall47, which is a cured body of the curable resin, has the constriction part between the both end portions in the thickness direction. Therefore, as described above embodiment, it is possible to increase the density of the fiber41in the fiber layer40and thus improve the optical characteristics. As a result, it is possible to increase the contrast in the electrophoretic device30.

In a third modified example, as shown inFIG. 15, a partition wall48is constituted of a first part48athat is extended from the translucent layer32toward the opposed layer31and a second part48bthat is extended from the opposed layer31toward the translucent layer32.

The first part width W1of the first part48ais substantially the same as the second part width W2of the second part48b. That is, the contact area of the partition wall48and the opposed layer31is substantially the same as the contact area of the partition wall48and the translucent layer32. Further, the first part48ahas a pentagonal prism shape that is extended along the lower surface of the translucent layer32and has the same width as the first part width W1up to substantially the center between the both end portions of the fiber layer40in the thickness direction. Furthermore, the second part48bhas a pentagonal prism shape that is extended along the upper surface of the opposed layer31and has the same width as the second part width W2up to substantially the center between the both end portions of the fiber layer40in the thickness direction. The edge of the first part48ahaving the pentagonal prism shape and the edge of the second part48bhaving the pentagonal prism shape are connected at substantially the center of the partition wall48in the thickness direction. A connection part48cis a constriction part of the partition wall48.

The first part48aand the second part48bhaving the structures described above are formed in the following way, for example. First, the intensity of the first UV ray54and the intensity of the second UV ray55are gradually increased, thereby forming the partition wall having the first part width W1and the partition wall having the second part width W2along the thickness direction of the fiber layer40. After that, the intensity of the first UV ray54and the intensity of the second UV ray55are abruptly decreased, thereby forming the connection part48c.

It should be noted that in the third modified example, as in the above embodiment and the second modified example, the part where the first part48aand the second part48bare connected with each other may be closer to the opposed layer31as compared to the center between the both end portions of the fiber layer40in the thickness direction. Alternatively, the part where the first part48aand the second part48bare connected with each other may be closer to the translucent layer32as compared to the center between the both end portions of the fiber layer40in the thickness direction.

According to the third modified example, the following effect can be obtained.

The first part48ahas the same width as the first part width W1up to substantially the center between the both end portions of the fiber layer40in the thickness direction. Further, the second part48bhas the same width as the second part width W2up to substantially the center between the both end portions of the fiber layer40in the thickness direction. Therefore, as compared to the structure in which the width of the first part48ais monotonously decreased from the translucent layer32toward the opposed layer31, it is possible to increase the mechanical rigidity of the partition wall48. Furthermore, as compared to the structure in which the width of the second part48bis monotonously decreased from the opposed layer31toward the translucent layer32, it is possible to increase the mechanical rigidity of the partition wall48.

In a fourth modified example, as shown inFIG. 16, a partition wall49is constituted of a first part49athat is tapered from the translucent layer32toward the opposed layer31and a second part49bthat is tapered from the opposed layer31toward the translucent layer32.

The first part thickness H1of the first part49ais larger than the second part thickness H2of the second part49b. That is, a connection part49cof the first part49aand the second part49bis formed to be closer to the opposed layer31than to the center between the both end portions of the partition wall49in the thickness direction. The connection part49cis a constriction part of the partition wall49.

The first part width W1of the first part49ais smaller than the second part width W2of the second part49b. That is, the contact area of the partition wall49and the opposed layer31is larger than the contact area of the partition wall49and the translucent layer32.

The first part49aand the second part49bhaving the structures described above are formed in the following way, for example. With the first UV ray54having the light cross-section larger than the second UV ray55, the interface between the translucent layer32and the cure-purpose resin53is irradiated with a larger intensity than the second UV ray55. As a result, the first part49ahaving the first part width W1smaller than the second part width W2is formed with the first part thickness H1larger than the second part thickness H2.

According to the fourth modified example, the following effect can be obtained.

The first part49ahaving the relatively small width is extended up to the position closer to the opposed layer31than to the center of the partition wall49in the thickness direction, so the image of the partition wall49is less likely to be visually confirmed on the display side.

In a fifth modified example, as shown inFIG. 17, a partition wall50is constituted of a first part50athat is extended from the translucent layer32toward the opposed layer31and a second part50bthat is tapered from the opposed layer31toward the translucent layer32.

The first part thickness H1in the first part50ais substantially the same as the second part thickness H2in the second part50b, and a connection part50aof the first part50aand the second part50bis formed substantially the center between the both end portions of the partition wall50in the thickness direction. Further, the first part width W1of the first part50ais substantially the same as the second part width W2of the second part50b.

In the second part50b, the width is monotonously decreased from the opposed layer toward the translucent layer32. On the other hand, in the first part50a, the width has a maximum value in the thickness direction. That is, in the partition wall50, a constriction part is formed at an intermediate position of the fiber layer40in the thickness direction, and a constriction part is formed also on an interface between the translucent layer32and the fiber layer40.

The first part50ahaving the structure described above is formed in the following way, for example. On a portion where the partition wall50is formed on the lower surface of the transparent electrode34, a photothermal film50dthat converts light into heat is laminated. The photothermal film50dis irradiated with light. At this time, as the curable resin53, a light curable resin and a thermosetting resin are used, with the result that the curing of the curable resin53progresses from a lower end surface of the photothermal film50d, and the curing of the curable resin53progresses from a side end surface of the photothermal film50d. Thus, in the partition wall50, the constriction parts are formed at the intermediate position between the both end portions of the fiber layer40in the thickness direction and on the interface between the translucent layer32and the fiber layer40.

According to the fifth modified example, the following effect can be obtained.

Because the curing of the curable resin53progresses from the photothermal film50d, it is possible to determine in advance the position where the partition wall50is formed with the position of the photothermal film50d. Therefore, even if the position excluding the photothermal film50dis irradiated with light for thermal conversion, it is possible to suppress the partition wall50from being formed from the position irradiated. As a result, it is possible to improve the accuracy of the position where the partition wall50is formed.

It should be noted that the partition wall may be formed by appropriately combining the first part43aand the second part43bin the above embodiment and the first parts46a,47a,48a,49a, and50aand the second parts46b,47b,48b,49b, and50bin the first to fifth modified examples, respectively.

(Modified Example of Electrophoretic Display Apparatus)

Hereinafter, a modified example of the electrophoretic display apparatus10will be described. It should be noted that this modified example is different from the electrophoretic display apparatus10in the above embodiment in the structure where the substrate20and the electrophoretic device30are connected. In the following, the different point will be described in detail.

As shown inFIG. 18, between the TFT layer22and the fiber layer40, an adhesion layer38and an opposed layer39are sandwiched. The adhesion layer38is a film member that protects the pixel electrodes25against a mechanical contact and has an adhesion property with the opposed layer39, and is bonded to the upper surface of the TFT layer22. The opposed layer39is a film member having a sealing property that seals the electrophoretic particles and the liquid containing the fiber layer40in the fiber layer40, and is bonded to the lower surface of the fiber layer40. The opposed layer39has a permeable property that is permeable by the curing energy described above and may double as the cure-purpose substrate52.

According to the modified example, the following effect can be obtained.

Because the adhesion layer38and the opposed layer39are formed of different members, it is possible to handle the electrophoretic device30and the substrate20separately. Therefore, it is possible to improve the handling performance of the electrophoretic device30and the substrate20and improve the handling performance of the members in the manufacturing process of the electrophoretic display apparatus10.

Because the opposed layer39doubles as the cure-purpose substrate52, it is possible to reduce the number of members necessary for manufacturing the electrophoretic devices30as compared to the case where the opposed layer39and the cure-purpose substrate52are separately prepared.

An electronic apparatus provided with the electrophoretic display apparatus10described above will be described. It should be noted that the electrophoretic display apparatus10can be applied to various use purposes and is not particularly limited. Therefore, in the following, the structure in which the electrophoretic display apparatus10is applied to an electronic apparatus provided with a display unit will be described, but the structure is merely an example, and various changes can be made.

As shown inFIG. 19, a casing101of an electrical book terminal100is equipped with a display unit102formed of the electrophoretic display apparatus10and operation buttons103for operating a display mode on the display unit102.

As shown inFIG. 20, a lower side casing111of a personal computer110is equipped with a keyboard112and an operation unit113, an upper side casing114of the personal computer110is equipped with a display unit115formed of the electrophoretic display apparatus10.

As shown inFIG. 21, a casing122attached to a support table121of a television120is equipped with a display unit123formed of the electrophoretic display apparatus10.

As shown inFIG. 22, on one surface of a casing131of a digital still camera130, a lens132that takes an image of an image pickup target and an image pickup button133for causing the digital still camera130to take an image are formed. Further, as shown inFIG. 23, on the other surface of the casing131, a display unit134formed of the electrophoretic display apparatus10and an operation button135are provided.

As shown inFIG. 24, a casing141of a digital video camera140is equipped with a lens142and an operation button143. Further, to the casing141, a display unit casing145is connected through a connection unit144, and to the display unit casing145, a display unit146formed of the electrophoretic display apparatus10is provided.

As shown inFIG. 25, a lower side casing151provided to a mobile phone terminal150is equipped with operation buttons152, and to the lower side casing151, an upper side casing154is connected through a connection unit153. To the upper side casing154, a display unit155formed of the electrophoretic display apparatus10is provided. Further, as shown inFIG. 26, on a surface opposed to the display unit155of the upper side casing154, a back surface display unit156formed of the electrophoretic display apparatus10is provided.

It should be noted that the present disclosure can take the following configurations.

a fiber layer;

an electrophoretic particle configured to migrate through a gap in the fiber layer; and

a partition wall extended in a thickness direction of the fiber layer to separate the fiber layer into a plurality of migration cells, the partition wall including a cured body of a curable resin, the cured body including a constriction part between both end portions of the fiber layer in the thickness direction.

(2) The electrophoretic device according to Item (1), further including:

a translucent layer configured to cause light to pass therethrough; and

an opposed layer configured to cause the fiber layer to be sandwiched along with an insulating liquid, in which

the constriction part is closer to the translucent layer than to the opposed layer.

(3) The electrophoretic device according to Item (1) or (2), further including:

a translucent layer configured to cause light to pass therethrough; and

an opposed layer configured to cause the fiber layer to be sandwiched along with an insulating liquid, in which

a contact area of the partition wall and the translucent layer is smaller than a contact area of the partition wall and the opposed layer.

(4) The electrophoretic device according to any one of Items (1) to (3), further including:

a translucent layer configured to cause light to pass therethrough; and

an opposed layer configured to cause the fiber layer to be sandwiched along with an insulating liquid, in which

the partition wall includes

a first part that is tapered from the translucent layer toward the constriction part, and

a second part that is tapered from the opposed layer toward the constriction part.

(5) The electrophoretic device according to any one of Items (1) to (4), in which

the curable resin is a light curable resin.

(6) The electrophoretic device according to any one of Items (1) to (5), in which

the fiber layer is formed of a fiber that is a resin fiber in which non-electrophoretic particles that reflect light are held while being dispersed, and

a distance between the non-electrophoretic particles in the fiber is shorter than a wavelength of visible light.

(7) The electrophoretic device according to any one of Items (1) to (6), in which

the partition wall partitions the fiber layer into the plurality of migration cells, and

the fiber layer is formed of a fiber that includes a part inside the partition wall which is buried in the partition wall and a part outside the partition wall which is positioned in the migration cells.

(8) The electrophoretic device according to any one of Items (1) to (7), in which

the fiber layer is porous.

The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2012-112882 filed in the Japan Patent Office on May 16, 2012, the entire content of which is hereby incorporated by reference.