Electro-optical device, method of manufacturing electro-optical device and electronic apparatus

An electro-optical device includes a pair of substrates arranged so as to face each other, an electro-optical material layer interposed between the pair of substrates, a through hole penetrating through the pair of substrates and the electro-optical material, and a encapsulating member disposed in the through hole for sealing the electro-optical material layer while being disposed between the pair of substrates, in which the encapsulating member is disposed closer to the electro-optical material layer than an outer surface of a display substrate of the pair of substrates and outside an entrance portion of the through hole, in a plan view, the entrance portion being on an outer surface side of the display substrate.

BACKGROUND

1. Technical Field

The present invention relates to an electro-optical device, a method of manufacturing an electro-optical device, and an electronic apparatus.

2. Related Art

Electro-optical devices, such as liquid crystal devices and electrophoretic devices have been widely used, for example, as displays of mobile phones, display parts of watch faces, and light bulbs of projectors. Generally, an electro-optical device is composed of a pair of substrates made of glass or the like and an electro-optical material layer interposed between the substrates. An electro-optical device used as a face of an analog watch has a through hole in a display region with a hand spindle installed therein.

JP-UM-A-56-123320 discloses a technique in which a through hole is provided in a display region, and a sealing material is provided in the through hole in order to prevent impurities from intruding into an electro-optical material layer. That is, the electro-optical material layer is sealed by the sealing material. In addition, there is a further known technique in which a sealing material is provided around the through hole in a display region and an encapsulating member made of resin or the like is further provided so as to cover the sealing material and an inner surface of the through hole. According to this technique, thanks to the dual-sealing scheme, it is possible to reliably prevent impurities from intruding into the electro-optical material layer.

However, the above-mentioned known techniques have a problem in that a user can apparently discern the encapsulating member from the substrate around the hand spindle when the user watches the face of a watch because the substrate and the encapsulating member are made of different materials. At this time, the user may not like the appearance of the watch having the above structure. This may significantly influence marketability of products particularly in the case in which the products are watches or the like having a commercial value which is greatly influenced by the appearance thereof.

SUMMARY

An advantage of the invention is that it provides an electro-optical device, a manufacturing method of an electro-optical device and an electronic apparatus, which have a high commercial value and an appearance which users do not find unattractive.

According to one aspect of the invention, there is provided an electro-optical device including a pair of substrates arranged so as to face each other, an electro-optical material layer interposed between the pair of substrates, a through hole penetrating through the pair of substrates and the electro-optical material layer, and an encapsulating member disposed in the through hole so as to seal the electro-optical material layer while being disposed between the pair of substrates, in which the encapsulating member is disposed closer to the electro-optical material layer than an outer surface of a display substrate of the pair of substrates and disposed outside an entrance portion of the through hole, which is on an outer surface side of the display substrate, in a plan view.

According to this aspect, since the electro-optical device includes a pair of substrates arranged so as to face each other, an electro-optical material layer interposed between the pair of substrates, a through hole penetrating through the pair of substrates and the electro-optical material layer, and an encapsulating member provided in the through hole so as to seal the electro-optical material layer while being disposed between the pair of substrates, in which the encapsulating member is disposed closer to the electro-optical material layer than an outer surface of a display substrate of the pair of substrates and disposed outside an entrance portion of the through hole, which is on an outer surface side of the display substrate, in a plan view, there is no probability that the encapsulating member is present on the outer surface of the display substrate around the entrance portion of the through hole. It is therefore possible to realize the electro-optical device having appearance which is displeasing viewers and having a high commercial value.

In the electro-optical device, it is preferable that an inner surface of the through hole, on which the encapsulating member is disposed, is rough.

In this case, since the inner surface of the through hole, on which the encapsulating material is disposed, is rough, it is possible to increase a contact area that the inner surface of the through hole contacts the encapsulating member. Thanks to this structure, it is possible to inhibit impurities from intruding into the electro-optical material layer.

In the electro-optical device, it is preferable that the encapsulating member penetrates through one substrate of the pair of substrates, which is other than the display substrate.

In this case, since the encapsulating member penetrates through the substrate other than the display substrate, it is possible to inhibit impurities from intruding into the electro-optical material layer.

In the electro-optical device, it is preferable that the encapsulating member is disposed closer to the electro-optical material layer than an outer surface of the substrate other than the display substrate.

In this case, since the encapsulating member is disposed closer to the electro-optical material layer than the outer surface of the substrate other than the display substrate, the encapsulating member is present neither on the outer surface of the display substrate nor on the outer surface of the substrate which is other than the display substrate. That is, the encapsulating member is completely received in the electro-optical device. As a result, it is possible to obtain the encapsulating member having a stable form.

In the electro-optical device, it is preferable that the electro-optical material layer is an eletrophoresis layer having a plurality of capsules, each being composed of colored particles which cause an electrophoretic reaction and a dispersion medium for making the colored particles disperse therein.

In this case, the electro-optical material layer is an electrophoresis layer having a plurality of capsules, each containing colored particles which cause an electrophoretic reaction and a dispersion medium for making the color particles disperse therein. Accordingly, there is no risk that electro-optical material of the electro-optical material layer leaks out as a liquid behaves like such. For this reason, it is possible to decrease area of the encapsulating member, and thus it is possible to increase area of a display region.

According to another aspect of the invention, there is provided a method of manufacturing an electro-optical device including a pair of substrates arranged so as to face each other and an electro-optical material layer interposed between the pair of substrates. The method includes arranging the pair of substrates to so as face each other, forming a continuous hole which links the electro-optical material layer with the pair of substrates except for part of a display substrate of the pair of substrates, which is on an outer surface side of the display substrate, sealing the electro-optical material layer inside the continuous hole and forming a through hole which penetrates through the pair of substrates and the electro-optical material layer and which has a diameter smaller than that of the continuous hole within a region where the continuous hole is provided.

According to this aspect, since an electro-optical device is manufactured by arranging a pair of substrates so as to face each other, forming a continuous hole which links the electro-optical material layer with the pair of substrates except for part of a display substrate of the pair of substrates, which is on an outer surface side of the display substrate, sealing the electro-optical material layer inside the continuous hole and forming a through hole which penetrates through the pair of substrates and the electro-optical material layer and which has a diameter smaller than that of the continuous hole within a region where the continuous hole is provided, it is possible to manufacture the electro-optical device without allowing the encapsulating member to be present around an entrance to the through hole on an outer surface of the display substrate. Thus, it is possible to realize an electro-optical device having appearance which is not displeasing viewers and having a high commercial value.

In the method, it is preferable that the continuous hole is formed through a procedure in which a first concave is formed in the display substrate before arranging the pair of substrates so as to face each other in a manner such that the first concave terminates at a midway portion of the display substrate so that part of the display substrate, which is on the outer surface side of the display substrate remains unpenetrated, a second concave is formed in one substrate other than the display substrate in a manner such that the second concave terminates at a midway portion of the substrate other than the display substrate so that part of the substrate, which is on an outer surface side of the substrate, remains unpenetrated, and the display substrate and the substrate other than the display substrate are arranged in a manner such that the first concave and the second concave face each other.

In the method, it is preferable that the continuous hole is formed so as to penetrate through the substrate other than the display substrate.

In this case, since the continuous hole penetrates through the substrate other than the display substrate, it is possible to easily seal the electro-optical material layer.

In the method, it is preferable that the electro-optical material layer is a liquid crystal layer and is placed between the pair of substrates after formation of the through hole.

In this case, since the electro-optical material layer is a liquid crystal layer and is placed between the pair of substrates after formation of the through hole, it is possible to reliably seal the electro-optical material layer even if the electro-optical material layer is in the form of a liquid layer like a liquid crystal layer.

According to further aspect of the invention, there is provided an electronic apparatus including the electro-optical device according to the above aspect of the invention or the electro-optical device manufactured by the manufacturing method according to the above aspect of the invention.

According to the invention, it is possible to realize an electronic apparatus with good design by mounting the electro-optical device having appearance which is not displeasing viewers and having a high commercial value on the electronic apparatus.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

First Embodiment

FIG. 1shows a structure of a wrist watch in which an electro-optical device according to a first embodiment is mounted. The wrist watch100includes a watch face101, a hand spindle102, a minute hand103, an hour hand104and a second hand105. The watch face101is mainly composed of an electrophoretic device10.

FIG. 2shows a structure of the electrophoretic device10. As shown inFIG. 2, the electrophoretic device10is mainly composed of a pair of substrates (a display substrate1and an element substrate2) arranged to face each other and an electro-optical material layer3interposed between the display substrate1and the element substrate2. The electrophoretic device10includes a plurality of sub-pixels displaying different colors. The sub-pixels are arranged in a matrix form. There are red sub-pixels displaying red color, green sub-pixels displaying green color, blue sub-pixels displaying blue color, and black sub-pixels displaying black color. One red sub-pixel, one green sub-pixel, one blue sub-pixel, and one black sub-pixel constitute one pixel.

The display substrate1is made of a light-transmissible material such as glass or the like. The display substrate1is a plate-shaped member having a thickness of 500 μm. An outer surface1aof the display substrate1serves as a display surface on which still image pictures, motion image pictures or the like are displayed.

The element substrate2can be made of a variety of materials, such as glass, plastic, and a metal plate, for example a stainless steel plate, with an insulation layer thereon. The element substrate2may be a plate-shaped member having a thickness of 500 μm. The element substrate is not necessarily light-transmissible.

A pixel electrode layer7is formed on an inner surface2bof the element substrate2. The pixel electrode layer7is provided with pixel electrodes for driving the electro-optical material layer3sub-pixels by sub-pixels, Thin-film Transistors (TFTs) for controlling the corresponding pixel electrodes, data lines and scan lines which supply electrical signals to the corresponding TFTs.

The electro-optical material layer3is composed of a film4, a common electrode5, and a plurality of microcapsules6. The film4is a plate-shaped member made of a light-transmissible material, for example, polyethylene terephthalate (PET) and is bonded to the inner surface1bof the display substrate1. The common electrode5is made of a light-transmissible conductive material, for example, Indium Tin Oxide (ITO) and is formed over almost the entire face4aof the film4.

Each of the microcapsules6has a particle diameter of about 50 μm and is made of light-transmissible polymeric resin, for example, acryl resin, such as polymethacrylic acid methyl, polymethacrylic acid ethyl, or the like, urea resin, and Arabia rubber, or the like. The microcapsules6are disposed between the common electrode5and the pixel electrode layer7. One sub-pixel includes a plurality of microcapsules6arranged in rows and columns. Each sub-pixel is provided with a binder which fills a gap around the microcapsule6in order to secure the microcapsule6.

At a substantial center portion of the electrophoretic device10in a plan view thereof, a through hole8is formed so as to penetrate through the display substrate1, the element substrate2and the electro-optical material layer3. A hand spindle102is installed in the through hole8. The through hole8is composed of a continuous portion8aand an entrance portion8b. The continuous portion8ais formed so as to link the element substrate2, the electro-optical material layer3, and part of the display substrate1which is on a side of an inner surface1bof the display substrate1, with each other. The entrance portion8bis disposed on a side of an outer surface1aof the display substrate1. The diameter of the continuous portion8ais larger than that of the entrance portion8band gradually decreases from the continuous portion8atoward the entrance portion8b.

An encapsulating member9is disposed in the continuous portion8bof the through hole8. The encapsulating member9is made of transparent resin such as epoxy resin or the like. The encapsulating member9seals the electro-optical material layer3while being disposed between the display substrate1and the element substrate2. The continuous portion8bis disposed at a center portion of the electrophoretic device10in a plan view and has an inner diameter the same as or larger than the diameter of the entrance portion8bby 200 μm to 4 mm and more preferably larger by 600 μm.

The encapsulating member9is not present on the outer surface1aof the display substrate1but disposed near the electro-optical material layer3. In detail, the encapsulating member9is provided so as not to be present on part of the display substrate1which is on an outer surface side of the display substrate1and has a thickness of t from the outer surface1aof the display substrate1. The thickness t is preferably not smaller than 50 μm and more preferably is about 200 μm. The encapsulating member9is preferably disposed outside the entrance portion8bof the through hole8, which is disposed on the outer surface side of the display substrate1, in a plan view. Thickness d of the encapsulating member9is in a range from 100 μm to 2 mm.

FIGS. 3 and 4show the inner structure and operation of the microcapsule6, respectively. As shown inFIG. 3, a dispersion liquid11, white particles12, and colored particles13are sealed in the microcapsule6.

The dispersion liquid11can include water; an alcohol solvent, such as methanol, ethanol, isopropanol, butanol, octanol, and methyl cellosolve; esters such as ethyl acetate and butyl acetate; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl tekone; aliphatic hydrocarbons such as ethyl acetate and pentane, hexane, and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and zylene; long-chain alkylbenzenes such as hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dedecylbenzene, tridecylbenzene, and tetradecylbenzene; hydrocarbon halides such as methylene chloride, chloroform, carbon tetrachloride, and 1,2-dichloroethane; carboxylate; and other oils. These compounds can be used alone or in the form of a mixture thereof, in both cases being mixed with a surfactant. The dispersion liquid disperses white particles12and colored particles13therein.

The white particles12and the colored particles13have a property of migrating in the dispersion liquid11, based on an electrophoretic phenomenon caused by a potential difference. The white particles12are particles (polymer or colloid) containing white pigment such as titanium dioxide, zinc oxide, and antimony trioxide and are positively charged.

The colored particles13(polymer or colloid) are composed of particles containing black pigment, such as aniline black, carbon black, or the like; azo-based pigment, such as monoazo, disazo, and polyazo; yellow pigment, such as isoindoline, chrome yellow, yellow iron oxide, cadmium yellow, titan yellow, antimony, or the like; red pigment, such as quinacridone red, chrome vermillion, or the like; blue pigment, such as phthalocyanine blue, indanthrene blue, anthraquinone, iron blue pigment, ultramarine blue pigment, cobalt blue, or the like; and green pigment such as phthalocyanine green. The colored particles are negatively charged. The colored particles13in a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a black pixel are colored red, green, blue and black, respectively.

According to circumstances, the pigments may be mixed with a charge control agent containing electrolyte, surfactant, metal soap, resin, rubber, oil, varnish, and compound particles; a dispersion agent, such as titanium-based coupling agent, aluminum-based coupling agent, and silan-based coupling agent; lubricant agent; and stabilizer.

In operation of the microcapsule6having the above structure, as shown inFIG. 4A, when the pixel electrode is applied with a voltage contributing to a negative potential of the pixel electrode in the pixel electrode layer7, colored particles13which are positively charged by column force migrate to the pixel electrode in the microcapsule6by attraction, and conversely the white particles12which are negatively charged migrate to the common electrode5in the microcapsule6by attraction. As a result, the white particles12gather on a display surface of the microcapsule6and thus color (white color) of the white particles12is displayed on the outer surface1a.

Conversely, as shown inFIG. 4B, when the pixel electrode is applied with a voltage contributing to a positive potential of the pixel electrode, the white particles12which are negatively charged by column force migrate to the pixel electrode7by attraction and the colored particles13which are positively charged are migrate to the common electrode5by attraction. As a result, the colored particles13gather on the display surface of the microcapsule6and thus a color (red, green, blue or black) is displayed on the outer surface1a.

Hereinafter, a method of manufacturing the electrophoretic device10having the above structure will be described. As shown inFIG. 5, pixel electrodes, TFTs, data lines and scan lines are formed on an inner surface2aof an element substrate2to form a pixel electrode layer7in the first place. A film4with a common electrode5and a plurality of microcapsules6is bonded to the pixel electrode layer7. The microcapsules6, the pixel electrodes, and the TFTs are arranged so as not to be disposed at a center portion, in a plan view, of the display substrate1and the element substrate2. The data lines and the scan lines extend around the center portion, in a plan view, of the display substrate1and the element substrate2. Then, as shown inFIG. 5, the display substrate1and the element substrate2are bonded to each other.

Subsequently, as shown inFIG. 6, a continuous portion8ais formed so as to link the element substrate2, the electro-optical material layer3and part of the display substrate1, which is on a side of the inner surface1aof the display substrate1, with each other. In detail, a hole is formed by drilling the element substrate2, the electro-optical material layer3, and the display substrate1using a drill in a manner such that the element substrate2and the electro-optical material layer3are completely penetrated and part of the display substrate is penetrated, while leaving part of the display substrate1, which has a thickness of 200 μm from the outer surface1aof the display substrate1, unpenetrated.

As shown inFIG. 7, thermosetting resin, for example, epoxy resin15having a viscosity of 10 to 5000 cp at room temperature is injected into the continuous portion8ausing a dispenser. If the viscosity is not higher than 10 cp, there is a risk that the epoxy resin15leaks out. Conversely, if the viscosity is not lower than 5000 cp, it is difficult for the epoxy resin to spread over the entire surface of the continuous portion8a. According to this embodiment, the ideal viscosity of the thermosetting resin is about 2000 cp.

After injection of the epoxy15, the epoxy resin15is cured at a temperature in a range from 100 to 120° C. for one hour while not causing damage to the microcapsules6. After the epoxy resin15is cured, a through hole8is formed so as to penetrate through the epoxy resin15and the display substrate1, while simultaneously forming the encapsulating member9. Thus, the electrophoretic device10shown inFIG. 2is completed.

According to this embodiment, in the through hole8, the encapsulating member9is formed closer to the electro-optical material layer3than the outer surface1aserving as a display surface of the display substrate1and is formed outside the entrance portion8bof the through hole8which is on an outer surface side of the display substrate, in a plan view. Accordingly, there is no probability that the encapsulating member9is exposed around the entrance portion8bof the through hole8, which is on a side of the outer surface1aof the display substrate1. Accordingly, it is possible to obtain the electrophoretic device10having appearance which is not displeasing viewers and having a high commercial value.

According to this embodiment, since the encapsulating member9is provided so as to penetrate through the element substrate2, it is possible to reliably seal the electro-optical material layer3and thus it is possible to inhibit impurities from intruding into the electro-optical material layer3.

Second Embodiment

Hereinafter, an electrophoretic device according to a second embodiment will be described. In description relating to the second embodiment, like elements in the first embodiment and second embodiment will not be explained at all or briefly explained.

As shown inFIG. 8, the electrophoretic device210is for use in a watch face of a wrist watch as in the first embodiment. The electrophoretic device210includes a pair of substrates (a display substrate201and an element substrate202) and an electro-optical material layer203interposed between the pair of substrates as main components. The structures of the display substrate201, the element substrate202, and the electro-optical material layer203according to this embodiment are substantially the same as in the first embodiment. Accordingly, explanation thereof will be omitted.

A through hole208is formed at an almost center portion of the electrophoretic device210in a plain view so as to penetrate through the display substrate201, the element substrate202and the electro-optical material layer203. A hand spindle is installed in the through hole208. The through hole208is composed of a continuous portion208a, an entrance portion208band an exit portion208c.

The continuous portion208alinks part of the display substrate201on an inner surface side of the display substrate201, part of the element substrate202on an inner surface side of the element substrate202and the electro-optical material layer203with each other. That is, the structure of the second embodiment is different from the structure of the first embodiment in that the continuous portion208adoes not completely penetrate through the element substrate202. The entrance portion208bis disposed on a side of an outer surface201aof the display substrate201and the exit portion208cis disposed on a side of an outer surface202aof the element substrate202. Diameters of the entrance portion208band the exit portion208care almost the same as each other. However, diameter of the continuous portion208ais larger than those of the entrance portion208band the exit portion208cby about 200 μm to 4 mm. That is, diameter of the through hole208gradually decreases toward the entrance portion208band toward the exit portion208c, respectively from the continuous portion208a.

The continuous portion208aof the through hole208is provided with an encapsulating member209. The encapsulating member209is made of transparent resin, such as epoxy resin as in the first embodiment. The encapsulating member209seals the electro-optical material layer203while being disposed between the display substrate201and the element substrate202. In a top plan view, the encapsulating member209is provided at a center portion of the electrophoretic device10and has an inner diameter which is almost the same as or larger than the diameter of the entrance portion208bof the through hole208.

The encapsulating member209is not present on the outer surface201aof the display substrate201and is disposed closer to the electro-optical material layer3than the outer surface201aof the display substrate201as in the first embodiment. Since the continuous portion208does not penetrate through the element substrate202, the encapsulating member209is not present on the outer surface202aof the element substrate202. This makes different the second embodiment from the first embodiment.

The continuous portion208aof the through hole208and the encapsulating member209is not disposed on part of the display substrate201on the outer surface side thereof. The part has a thickness not smaller than 50 μm, for example a thickness of 200 μm from the outer surface201aof the display substrate as in the first embodiment. The encapsulating member209is formed outside the entrance portion208aof the through hole208which is on the outer surface side of the display substrate201in a plan view. A thickness of the encapsulating member is preferably in a range from 100 μm to 2 mm.

Hereinafter, a method of manufacturing the electrophoretic device210having the above structure will be described. As shown inFIG. 9, first a hole208dhaving a diameter 600 μm larger than the diameter of the through hole208is formed at a center portion of the display substrate201, in a plan view, by drilling the display substrate201. At this time, the hole208ddoes not completely penetrate through the display substrate201but terminates at a midway of the display substrate201, in which a distance from the outer surface201aof the display substrate201is about 200 μm at the terminating position.

Separately, a common electrode205is formed on a film204and microcapsules206are coated on the film204. The film204provided with the common electrode205and the microcapsules206are attached to the element substrate202using an adhesive sheet. After the film204is attached to the element substrate202, a hole208eis formed at a center portion of the element substrate202in a plan view by drilling the element substrate202from the film204using a drill having a diameter the same as that of the drill used when forming the hole208d. At this time, part of the element substrate202which is on an outer surface side of the element substrate and which has a thickness of 200 μm from the outer surface202athereof remains undrilled.

In this state, the display substrate201and the element substrate202are arranged in a manner such that the hole208dand the hole208eof the display substrate201and the element substrate202, respectively face each other. When the display substrate201and the element substrate202are aligned in a manner such that the hole208dand the hole208eoverlap each other in a plan view of the display substrate201. After finishing the alignment, the display substrate201is bonded to the film204of the element substrate202using an adhesive.

After the display substrate201is bonded to the film204, as shown inFIG. 10, an entrance portion208band an exit portion208care formed by drilling the remaining parts of the display substrate201and the element substrate202at a position in which the holes208dand208eare formed using a drill having a diameter the same as the diameter of the through hole208.

After formation of the entrance portion208band the exit portion208c, as shown inFIG. 11, a resin tape220made of heat-resistive material, such as polyimide is attached to the outer surface202aof the element substrate202so as to block the exit portion208c, and then epoxy resin215having a viscosity of 2000 cp is injected into the through hole208through the entrance portion208bat room temperature using a dispenser.

After injection of epoxy resin215, the epoxy resin215is heated to and at a temperature in a range from 100 to 120° C. for an hour without causing damage to the microcapsules206, so that the epoxy resin215is cured. After curing the epoxy resin215, as shown inFIG. 12, the resin tape220is removed and then a hole is formed so as to completely penetrate through the epoxy resin215using a drill having a diameter the same as the diameter of the drill used when forming the entrance portion208band the exit portion208c, thereby finishing formation of the through hole208and encapsulating member209. Thus, the electrophoretic device10is completed.

According to this embodiment, an event that the encapsulating member209is present on the outer surfaces of the display substrate201and the element substrate202does not occur, and the whole encapsulating member209is completely received inside the electrophoretic device210. In this manner, the encapsulating member209can have a stable form.

Third Embodiment

Hereinafter, an electrophoretic device according to a third embodiment will be described. In description relating to this embodiment, like elements in the first embodiment and the third embodiment will not be explained at all or briefly explained.

As shown inFIG. 13, the electrophoretic device310is used as a watch face of a wrist watch as in the first embodiment. The electrophoretic device310mainly includes a pair of opposing substrates (a display substrate301and an element substrate302) arranged to face each other, and an electro-optical material layer303interposed between the display substrate301and the element substrate302. Since the structures of the display substrate301, the element substrate302, and the electro-optical material layer303are the same as those in the first embodiment, detailed description thereof will be omitted.

At a center portion of the electrophoretic device310in a plan view thereof, a through hole308penetrating through the display substrate301, the element substrate302and the electro-optical material layer303is formed. A hand spindle of the wrist watch is installed in the through hole308. The through hole308is composed of a continuous portion308aand an entrance portion308b.

The continuous portion308ais formed to link part of the display substrate301on an inner surface side thereof, the electro-optical material layer203and part of the element substrate202on an inner surface side thereof with each other as in the first embodiment. This structure is the same as in the first embodiment. However, the third embodiment is different from the first embodiment in that a surface in the continuous portion308aof the through hole308is rough. In detail, the entire surface of the continuous portion308ais provided with depressions and protrusions. The mean roughness (the mean depth of depressions and the mean height of protrusions) is about 10 to 20 μm. The encapsulating member309is formed to cover the entire surface in the continuous portion308a.

The depressions and protrusions of the rough surface of the continuous portion308acan be formed by using a drill with thread dimension larger than that of the drill used in the first and second embodiments. The depressions and protrusions on the rough surface also can be formed in an alternative manner, for example, an etching method.

According to this embodiment, since the surface in the through hole308at a position in which the encapsulating member309is provided is rough, it is possible to increase a contact area between the inner surface of the through hole308and the encapsulating member309, and thus it is possible to suppress impurities from intruding into the electro-optical material layer303.

Fourth Embodiment

Hereinafter, an electrophoretic device according to a fourth embodiment will be described. As shown inFIG. 14, the electrophoretic device410is used for a watch face of a wrist watch like the electrophoretic device according the first embodiment. The electrophoretic device410mainly includes a pair of substrates (a display substrate401and an element substrate402) arranged to face other, and an electro-optical material layer403interposed between the display substrate401and the element substrate402. The structures of the display substrate401, the element substrate402, and the electro-optical material layer403are almost the same as the structures as in the electrophorectic device according to the second embodiment. Accordingly, explanation thereof will be omitted.

A through hole408is formed at a center portion of the electrophorectic device410in a plan view thereof so as to penetrate through the display substrate401, the element substrate402and the electro-optical material layer403. The through hole408is an element for receiving a hand spindle therein. The through hole408is composed of a continuous portion408, an entrance portion408band an exit portion408c.

The continuous portion408alinks part of the display substrate401on an inner surface side thereof, the electro-optical material layer403and part of the element display substrate402on an inner surface side thereof with each other as in the second embodiment. The fourth embodiment is different from the second embodiment in that the surface in the continuous portion408ais rough. Other structures are the same as those of the second embodiment.

In detail, the entire surface of the continuous portion408ais provided with depressions and protrusions. The mean roughness (mean depth of the depressions and mean height of the protrusions) is about 10 to 20 μm. An encapsulating member409covers the entire rough surface of the continuous portion408a.

The depressions and protrusions on the surface of the continuous portion408aare formed by drilling the display substrate401, the electro-optical material layer403and the element substrate402using a drill having thread dimension larger than that of the drill used in the above embodiments. The depressions and protrusions can be formed in an alternative manner, for example, an etching method.

According to this embodiment, a portion of the surface of the penetration hole409, in which the encapsulating material409is provided, has a rough surface as in the third embodiment. Accordingly, it is possible to increase a contact area between the inner surface of the through hole408and the encapsulating member409. Thus, it is possible to suppress impurities from intruding into the electro-optical material layer403.

Fifth Embodiment

Hereinafter, a fifth embodiment will be described. The fifth embodiment relates to a liquid crystal device for use in a watch face of a wrist watch. As shown inFIG. 15, a liquid crystal device510mainly includes a pair of substrates (an opposing substrate501and a TFT array substrate502) arranged to face each other and an electro-optical material layer503interposed between the opposing substrate501and the TFT array substrate502. In this embodiment, the electro-optical material layer3is a liquid crystal layer.

The liquid crystal device510has a through hole508at an almost center portion thereof in a plan view, the through hole508penetrating through the opposing substrate501, the TFT array substrate502, and the electro-optical material layer503. A hand spindle is installed in the through hole508. The structures of the through hole508and an encapsulating member509are the same as in the first embodiment.

A method of manufacturing the liquid crystal device510having the above structure will be described below. As shown inFIG. 16, an opposing substrate501on which a common electrode505is formed and an TFT array substrate502on which pixel electrodes506, TFT elements and wirings are formed are bonded to each other with a sealing material therebetween, thereby forming a liquid crystal panel520. The sealing material has a liquid crystal injection hole therein.

After completion of the liquid crystal panel520, a hole is formed so as to penetrate through the TFT array substrate502and into part of the opposing substrate501at an almost center portion in a plan view of the panel520using a drill. Epoxy resin515is injected into the hole and cured. After that, a through hole508is formed to penetrate through the cured epoxy resin515and through the remaining part of the opposing substrate501, while producing the encapsulating member509.FIG. 17shows a structure of the liquid crystal device in which formation of the through hole508and the encapsulating member509is finished.

After forming of the through hole508, liquid crystal is injected into the structure shown inFIG. 17through the liquid crystal injection hole. As a result, an electro-optical material layer503in which liquid crystal is surrounded by the opposing substrate501, the TFT array substrate502and the sealing material is manufactured, as shown inFIG. 18. After formation of the electro-optical material layer503, the liquid crystal injection hole is blocked. Thus, the liquid crystal device510is completed.

According to this embodiment, the electro-optical material layer503is a liquid crystal layer, and liquid crystal is injected after formation of the through hole508. Accordingly, it is possible to reliably seal the electro-optical material layer503even in the case in which the electro-optical material layer is a liquid type layer such as a liquid crystal layer.

The scope of the invention is not limited to the above embodiments but it is understood that changes and variations may be made without departing from the spirit or scope of the invention. For example, even though a watch face101of a wrist watch100is illustrated as a flat face, but the invention can be applied to any structure in which the watch face101is a curved face, a pointed face or a multi-plane face composed of different planes inclining to each other at a predetermined angle.

Further, according to the embodiments, the microcapsule6contains a dispersion medium11, white particles12and colored particles13therein. However, the structure of the microcapsule will not be limited thereto. For example, the microcapsule may contain only a dispersion medium and white particles. In the case in which the microcapsule contains only a dispersion medium and white particles, the white particles12migrate to the pixel electrodes by attraction, so that the display portion may display a color of the dispersion medium.

Still further, the manufacturing method of the electrophoretic device according to the invention may be applied to a method of manufacturing a full-color electrophoretic display device in which a display portion has only white sub-pixels or black sub-pixels and a color filter is disposed on the display portion to realize a full-color display.

Yet further, the silicon views may displace the microcapsules6. The term “silicon views” refers to a particle in which a hemispherical face on one side thereof is negatively charged and colored white and a hemispherical face on the other side thereof is positively charged and colored any color other than white, in which the particle is sealed in a microcapsule. The silicon views can display a color in a display region based on direction change of the particle according to application of electric field.

In the embodiment, it is exemplified that the microcapsule6has a spherical shape but the shape of the microcapsule6may not be necessarily spherical but be, for example, rectangular.