JP6851153B2 - Electrophoresis display device and electronic equipment - Google Patents

Description

The present invention relates to an electrophoresis display device and an electronic device.

The electrophoresis display device has features such as display memory and a wide viewing angle when voltage application is stopped, and high contrast display with low power consumption.

Further, since the electrophoresis display device is a non-light emitting display device, it has a feature that it is easier on the eyes than a light emitting display device such as a cathode ray tube.

For example, in Patent Document 1, an electrophoresis layer having a dispersion medium provided on the first substrate and the second substrate arranged to face each other and separated into a plurality of cells by a partition wall, and between the electrophoresis layer and the second substrate. A bonding layer provided between the partition wall and the second substrate, a frame partition wall provided around the electrophoresis layer in a plan view, and a sealing material provided between the frame partition wall and the second substrate. An electrophoresis apparatus including a liquid pool portion provided between an electrophoresis layer and a frame partition wall in a plan view is disclosed.

In such an electrophoresis display device, positively or negatively charged electrophoresis particles are dispersed in the dispersion medium. Then, by generating an electric field between the first substrate and the second substrate, the electrophoretic particles are run to one substrate side, and a desired image is displayed.

Here, the liquid pool portion provided between the electrophoresis layer and the frame partition wall can store an excessively supplied dispersion medium when the electrophoresis apparatus is manufactured. This prevents the excess of the dispersion medium from flowing out of the electrophoresis apparatus. Further, even if bubbles are generated when the amount of the supplied dispersion medium is small, the influence of the bubbles on the image display is suppressed by retaining the bubbles in the liquid pool portion.

Japanese Unexamined Patent Publication No. 2015-018060

By the way, since the liquid pool portion does not contribute to the display of the image, a frame portion (bezel) is usually provided so as to cover the liquid pool portion and the sealing material in a plan view.

In recent years, there has been an increasing demand for narrower frames in order to increase the degree of freedom in designing electrophoresis display devices. However, there is a problem that the frame cannot be sufficiently narrowed due to the provision of the liquid pool portion.

An object of the present invention is to provide an electrophoresis display device capable of realizing a narrow frame while having a liquid pool portion, and a highly reliable electronic device provided with such an electrophoresis display device.

Such an object is achieved by the following invention.
The electrophoresis display device of the present invention includes a partition wall member arranged between the first substrate and the second substrate, and
The electrophoretic dispersion liquid arranged in the pixels partitioned by the partition member and
A seal portion located outside the display area including the plurality of pixels and arranged between the first substrate and the second substrate.
A liquid pool portion provided between the display area and the seal portion,
Have,
The liquid pool portion is characterized in that it includes a recess provided in at least one of the first substrate and the second substrate.

As a result, an electrophoresis display device capable of narrowing the frame while having a liquid pool portion can be obtained. Then, it is possible to realize an electrophoresis display device having a high degree of design freedom.

In the electrophoresis display device of the present invention, it is preferable that the recess is composed of a groove provided continuously or intermittently.

As a result, by forming the recesses intermittently, the volume of the liquid pool portion can be easily adjusted and formed by appropriately changing the ratio of the lengths for forming the recesses. Further, by continuously forming the concave portion, the volume of the liquid pool portion can be expanded as a whole. Therefore, even if the site where the surplus of the electrophoresis dispersion liquid is generated is biased, the surplus can be distributed to the entire liquid pool portion.

In the electrophoresis display device of the present invention, the first substrate includes a pixel substrate and an insulating layer provided on the electrophoresis layer side of the pixel substrate.
The recess preferably includes a portion where the insulating layer is not partially provided.

As a result, the recess can be formed without processing the pixel substrate, which has the advantage of being easy to manufacture. Further, since it is not necessary to process the pixel substrate, it is possible to avoid deterioration of mechanical characteristics and cost increase of the pixel substrate due to processing.

In the electrophoresis display device of the present invention, the depth of the recess is preferably 1 μm or more and 500 μm or less.

Thereby, the volume of the liquid pool can be sufficiently expanded while minimizing the influence of the presence of the recess on the mechanical and optical characteristics of the electrophoretic display device. As a result, the frame can be narrowed without impairing the reliability of the electrophoresis display device.

The electronic device of the present invention is characterized by comprising the electrophoresis display device of the present invention.
As a result, an electronic device having high reliability and a high degree of design freedom can be obtained.

It is sectional drawing which shows 1st Embodiment of the electrophoresis display apparatus of this invention. It is a top view which shows the 1st Embodiment of the electrophoresis display apparatus of this invention. It is sectional drawing which shows the 1st modification of the insulating layer and the recess shown in FIG. It is sectional drawing which shows the 1st modification of the insulating layer and the recess shown in FIG. It is sectional drawing which shows the 1st modification of the insulating layer and the recess shown in FIG. It is a top view which shows the 2nd modification of the recess shown in FIG. It is a top view which shows the 2nd modification of the recess shown in FIG. It is a figure for demonstrating the manufacturing method of the electrophoresis display apparatus shown in FIG. It is a figure for demonstrating the manufacturing method of the electrophoresis display apparatus shown in FIG. It is a figure for demonstrating the manufacturing method of the electrophoresis display apparatus shown in FIG. It is a figure for demonstrating the manufacturing method of the electrophoresis display apparatus shown in FIG. It is sectional drawing which shows the 2nd Embodiment of the electrophoresis display apparatus of this invention. It is sectional drawing which shows the 3rd Embodiment of the electrophoresis display apparatus of this invention. It is a front view of the wristwatch to which the embodiment of the electronic device of this invention is applied. It is a side sectional view of the wristwatch shown in FIG. It is a perspective view which shows the structure of the electronic paper to which the embodiment of the electronic device of this invention is applied. It is a perspective view which shows the structure of the electronic notebook to which the embodiment of the electronic device of this invention is applied.

Hereinafter, preferred embodiments of the electrophoresis display device and electronic device of the present invention will be described with reference to the accompanying drawings.

<< First Embodiment >>
<Electrophoresis display device>
First, the first embodiment of the present invention will be described.

FIG. 1 is a cross-sectional view showing a first embodiment of the electrophoresis display device of the present invention. Further, FIG. 2 is a plan view showing a first embodiment of the electrophoresis display device of the present invention. Note that FIG. 1 corresponds to the cross-sectional view taken along the line AA shown in FIG. Further, in the following description, for convenience of explanation, the upper side in FIG. 1 will be referred to as “upper” and the lower side will be referred to as “lower”.

The electrophoresis display device 1 shown in FIG. 1 is a display device that displays a desired image by utilizing the migration of particles. The electrophoresis display device 1 includes a backplane 1A including a first substrate 11 and a pixel electrode 21, a second substrate 12 arranged to face the first substrate 11, a common electrode 22, and an electrophoresis layer 7. It is equipped with 1B.

Of these, the backplane 1A is insulated from the first substrate 11 including the flat pixel substrate 31 and the insulating layer 32 provided on the upper surface thereof, and the pixel electrodes 21 provided on the upper surface of the insulating layer 32. It includes an electric circuit (not shown) provided inside the layer 32 or the like. The electric circuit includes a drive circuit such as an active matrix circuit, and a drive signal is output to the pixel electrode 21 according to image data based on an image to be displayed on the electrophoresis display device 1. ..

On the other hand, the front plane 1B includes a second substrate 12 including a flat plate-shaped opposed substrate 41, a common electrode 22 provided on the lower surface of the second substrate 12, a partition wall member 35 for partitioning a plurality of pixels 34, and pixels. It is provided with an electrophoretic layer 7 which is arranged in 34 and contains an electrophoretic dispersion liquid 70 containing an electrophoretic particle 71 and a dispersion medium 72. The region of the electrophoresis layer 7 that contributes to the display of an image in a plan view is referred to as a “display region E”. The electrophoretic particles 71 located in the display region E migrate to the first substrate 11 side or the second substrate 12 side by the electric field generated between the pixel electrode 21 and the common electrode 22 based on the drive signal described above. As a result, the shade of color exhibited by the electrophoresis particles 71 changes, and the image is displayed in the display area E.

Further, the electrophoresis display device 1 shown in FIG. 1 is located outside the display area E (on the right side in FIG. 1) in a plan view, and is a seal portion 14 arranged between the first substrate 11 and the second substrate 12. A space 611 located between the display area E and the seal portion 14 in a plan view and provided between the first substrate 11 and the second substrate 12, and a recess formed in the first substrate 11. It has a liquid pool portion 61 including 612 and. Further, the electrophoresis display device 1 shown in FIG. 1 has a frame portion 5 (bezel) provided so as to cover the upper surface of the second substrate 12 from the outside of the display area E to the side surfaces of the front plane 1B and the back plane 1A. have. In FIG. 2, the frame portion 5 is not shown. Further, for example, when the electrophoresis display device 1 is incorporated into an electronic device, the liquid pool portion 61 can be configured to be covered with the case of the electronic device. Therefore, in such a case, the frame portion 5 is not provided. May be good.

As described above, the electrophoresis display device 1 shown in FIG. 1 has electricity arranged on a partition wall member 35 arranged between the first substrate 11 and the second substrate 12 and pixels 34 partitioned by the partition wall member 35. A seal portion 14 located outside the display region E including the electrophoresis dispersion liquid 70 and a plurality of pixels 34 and provided between the first substrate 11 and the second substrate 12, and the display region E. It has a liquid pool portion 61 provided between the seal portion 14 and the seal portion 14. The liquid pool portion 61 is provided in at least one of the space 611 provided between the first substrate 11 and the second substrate 12 and the first substrate 11 and the second substrate 12 (in the present embodiment). It is configured to include a recess 612 (provided in the first substrate 11).

In such an electrophoresis display device 1, since the liquid pool portion 61 is accompanied by not only the space 611 but also the recess 612, the volume is expanded by that amount. As a result, the liquid pool portion 61 has a sufficient volume without widening its width R (see FIG. 1). As a result, the function of the liquid pool portion 61, that is, the function of preventing the electrophoretic dispersion liquid 70 from flowing out to the outside and retaining the generated air bubbles can be fully exerted without widening the width R. Can be done. Further, when it is not necessary to increase the volume of the liquid pool portion 61, the width B (see FIG. 1) of the frame portion 5 can be sufficiently narrowed, so that the so-called narrow frame portion can be achieved. As a result, it is possible to realize the electrophoresis display device 1 having a high degree of design freedom while ensuring reliability based on the above-mentioned functions.

Hereinafter, the configuration of each part will be described in sequence.
The pixel substrate 31 included in the first substrate 11 and the opposing substrate 41 included in the second substrate 12 are sheet-shaped (flat plate-shaped) members, respectively. These may be either flexible or rigid.

Examples of the constituent materials of the pixel substrate 31 and the opposing substrate 41 include various resin materials and various glass materials. Of these, the facing substrate 41 is made of a material having particularly translucent properties. As a result, the upper surface of the facing substrate 41 shown in FIG. 1 becomes the display surface.

The thickness of the pixel substrate 31 and the facing substrate 41 is slightly different depending on the constituent materials thereof, and is not particularly limited, but is preferably about 50 μm or more and 2000 μm or less, and more preferably about 100 μm or more and 1000 μm or less. preferable.

The insulating layer 32 provided on the upper surface of the pixel substrate 31 is provided mainly for the purpose of insulating the upper and lower surfaces thereof and the electric circuit provided inside. This electric circuit includes a drive circuit such as an active matrix circuit as described above. The active matrix circuit includes data lines, scanning lines, switching elements, holding capacitance, and the like, and outputs a drive signal corresponding to the image data to the pixel electrode 21.

Examples of the constituent material of the insulating layer 32 include silicon-based materials such as silicon oxide and silicon nitride, acrylic resins, and resin-based materials such as silicone-based resins, and one or two of these. The above are used in combination.

Not only the first substrate 11 but also the second substrate 12 may include such an insulating layer. For example, an insulating layer may be provided between the facing substrate 41 and the common electrode 22.

The pixel electrode 21 and the common electrode 22 are provided to generate an electric field by applying a voltage between them to allow the electrophoresis particles 71 to run.

Of these, the pixel electrode 21 is provided for each pixel 34. As a result, it becomes possible to exhibit independent gradations and colors for each pixel 34, and an arbitrary image can be displayed as the entire display area E composed of the plurality of pixels 34.

On the other hand, the common electrode 22 is provided so as to straddle the plurality of pixels 34.
The pixel electrode 21 and the common electrode 22 are each made of a conductive material. The same applies to wiring and the like (not shown). Examples of the conductive material include various metal materials such as Al and Cu, various conductive polymer materials, and various conductive oxidations such as ITO (indium / tin oxide) and IZO (indium / zinc oxide). Materials and the like can be mentioned. Of these, the common electrode 22 is made of a particularly translucent material.

The partition wall member 35 partitions between the first substrate 11 and the second substrate 12 into a plurality of pixels 34. Then, the electrophoresis dispersion liquid 70 can be filled for each pixel 34.

The sealing portion 14 is located outside the display area E in a plan view, seals between the first substrate 11 and the second substrate 12 at the outer edge portion thereof, and seals the first substrate 11 and the second substrate 12 at the outer edge portion thereof. And are fixed to each other. As a result, even if the electrophoretic dispersion liquid 70 is accumulated in the liquid pool portion 61, it can be prevented from flowing out to the outside.

Further, the present embodiment has a sealing portion 63 provided on the outside of the sealing portion 14. The sealing portion 63 can further reinforce the sealing property of the sealing portion 14 and prevent the sealing portion 14 from being directly exposed to the outside air.

Examples of the constituent materials of the partition wall member 35, the sealing portion 14, and the sealing portion 63 include various resin materials. Further, in the partition wall member 35, the sealing portion 14, and the sealing portion 63, the constituent materials may be the same or different from each other.

The thickness of the seal portion 14 (length in the vertical direction in FIG. 1) is not particularly limited, but is preferably about 10 μm or more and 150 μm or less.

Further, the sealing portion 63 may be provided as needed, or may be omitted.
Further, the position where the sealing portion 14 and the sealing portion 63 are provided is not necessarily limited to the outer edge portion between the first substrate 11 and the second substrate 12. For example, in the case of a base material on the premise that the first substrate 11 and the second substrate 12 are separated into a plurality of pieces, it may be provided at the outer edge portion in the region corresponding to each piece. This also applies to the liquid pool portion 61, which will be described later.

Further, the present embodiment has a bonding layer 62 provided on the lower surface of the common electrode 22. The upper portion of the partition wall member 35 is joined to the joint layer 62 so as to bite into the joint layer 62. This makes it possible to prevent the electrophoresis dispersion liquid 70 from moving between adjacent pixels 34.

Examples of the constituent material of the bonding layer 62 include various resin materials such as acrylic resin, silicone resin, epoxy resin, and olefin resin.

As described above, the frame portion 5 according to the present embodiment is configured to cover the upper surface of the second substrate 12 from the outside of the display area E to the side surfaces of the front plane 1B and the back plane 1A. Since the outside of the display area E can be covered by the frame portion 5, the design of the electrophoresis display device 1 can be enhanced. Further, by reinforcing the outer edge portion of the front plane 1B and the back plane 1A, the electrophoresis display device 1 can be protected from an external force, an impact, or the like.

The constituent material of the frame portion 5 is not particularly limited, and examples thereof include various resin materials and various metal materials.

The electrophoresis dispersion liquid 70 contains the electrophoresis particles 71 and the dispersion medium 72.
The electrophoretic particles 71 are positively or negatively charged and exhibit a color different from that of the dispersion medium 72.

The color exhibited by the electrophoresis particles 71 is not particularly limited. For example, when the dispersion medium 72 is light or white, it is preferably dark or black, and conversely, the dispersion medium 72 is dark or dark. When it is black, it is preferably light or white.

Further, the electrophoresis particles 71 may include a plurality of types of particles having different colors from each other. In that case, it is preferable that the polarities of the charges charged between the particles of different colors are different. In that case, the dispersion medium 72 is preferably transparent.

Examples of the electrophoresis particles 71 include oxide-based particles such as titanium oxide, zinc oxide, iron oxide, chromium oxide, and zirconium oxide, nitride-based particles such as silicon nitride and titanium nitride, and sulfide-based particles such as zinc sulfide. Particles, boride-based particles such as titanium boboride, inorganic pigment particles such as strontium chromate, cobalt aluminate, subchromium copper, and ultramarin, organic pigments such as azo-based, quinacridone-based, anthraquinone-based, dioxazine-based, and perylene-based Particles and the like can be used. Further, composite particles in which a pigment is applied to the surface of resin particles composed of acrylic resin, urethane resin, urea resin, epoxy resin, polystyrene, polyester or the like can also be used.
Further, the surface of the above-mentioned particles may be subjected to various surface treatments.

The dispersion medium 72 is not particularly limited, but a liquid having a boiling point of 100 ° C. or higher and high insulating properties is preferably used. Specifically, for example, various waters, alcohols such as butanol and glycerin, cellosolves such as butyl cellosolve, esters such as butyl acetate, ketones such as dibutylketone, and aliphatic hydrocarbons such as pentane (liquid paraffin), Aliphatic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as xylene, halogenated hydrocarbons such as methylene chloride, aromatic heterocycles such as pyridine, nitriles such as acetonitrile, N, N-dimethylformamide Examples thereof include amides such as, carboxylates, silicone oils and various other oils, and these can be used alone or as a mixture.

The liquid pool portion 61 includes a space 611 located between the display area E and the seal portion 14 in a plan view and provided between the first substrate 11 and the second substrate 12, as in the conventional case. That is, the space 611 is a space partitioned by the upper surface of the first substrate 11, the lower surface of the second substrate 12, the partition wall member 35 located on the outermost side, and the seal portion 14.

In addition to this, the liquid pool portion 61 according to the present embodiment includes a recess 612 (groove) formed in the first substrate 11 as shown in FIG. By providing the recess 612, the liquid pool portion 61 is expanded in the vertical direction of FIG. 1 as compared with the case where the liquid pool portion 61 is composed of only the space 611. Therefore, the volume of the liquid sump portion 61 can be increased without widening the width R of the liquid sump portion 61. In other words, it is possible to narrow the width R of the liquid sump portion 61 without reducing the volume of the liquid sump portion 61. As a result, for example, even if the display area E becomes wider and the amount of the electrophoresis dispersion liquid 70 that can be accumulated in the liquid pool portion 61 increases, more electrophoresis is performed without widening the width R of the liquid pool portion 61. The dispersion liquid 70 can be stored in the liquid reservoir 61.

As a result, it is possible to avoid widening the width B of the frame portion 5 or to make it narrower. As a result, the electrophoresis display device 1 having a higher degree of design freedom can be obtained. At the same time, since the risk of the electrophoresis dispersion liquid 70 leaking to the outside during or after production is reduced, a highly reliable electrophoresis display device 1 can be obtained.

For example, as shown in FIG. 2, when the display area E has a rectangular shape in a plan view, the liquid pool portion 61 is provided in a frame shape and continuously surrounding the display area E in a plan view. As a result, no matter which direction the electrophoresis dispersion liquid 70 provided in the display area E overflows, it is stored in the liquid pool portion 61 to prevent it from flowing out to the outside. Further, even if bubbles are generated in the electrophoresis dispersion liquid 70 in the manufacturing process of the electrophoresis display device 1, the bubbles can be easily retained in the liquid pool portion 61.

In addition, the liquid pool portion 61 may be hollow, but in many cases, a surplus portion of the electrophoretic dispersion liquid 70 is stored. Therefore, the liquid pool portion 61 is filled with a fluid such as a liquid. As described above, the liquid pool portion 61 is expanded in the thickness direction from the space 611 by the amount of the recess 612. Therefore, since the liquid pool portion 61, which is filled with the fluid, is widely present in the thickness direction, the stress that tends to be concentrated in the vicinity of the seal portion 14 can be easily relaxed. As a result, deterioration of the seal portion 14 due to stress concentration can be suppressed.

Further, as shown in FIG. 1, the liquid pool portion 61 is not provided with the pixel electrode 21 or the common electrode 22. Therefore, even if the electrophoresis dispersion liquid 70 is stored in the liquid pool portion 61, the electrophoresis particles 71 contained therein basically do not migrate. Therefore, for example, even if the width B of the frame portion 5 is made as small as possible so that the liquid pool portion 61 can be seen slightly, the liquid pool portion 61 always exhibits a constant color. If the color of the liquid pool portion 61 changes, the user may feel a sense of discomfort. Therefore, suppressing such discomfort is also one of the effects of the liquid pool portion 61.

Further, if the width R of the liquid pool portion 61 can be narrowed, the area of the pixel substrate 31 and the facing substrate 41 can be reduced. Thereby, for example, when cutting out a plurality of pixel boards 31 or facing boards 41 from one mother board, the number of sheets that can be cut out can be increased. As a result, the manufacturing cost of the electrophoresis display device 1 can be reduced.

Here, as described above, the first substrate 11 according to the present embodiment includes the pixel substrate 31 and the insulating layer 32 provided on the upper surface (electrophoretic layer 7 side) thereof.

The recess 612 according to the present embodiment includes a portion of the first substrate 11 in which the insulating layer 32 is not partially provided. That is, the recess 612 corresponds to the recess caused by the lack of the insulating layer 32. Since such a recess 612 can be formed without processing the pixel substrate 31, it has an advantage that it is easy to manufacture. Further, since it is not necessary to process the pixel substrate 31, it is possible to avoid a decrease in mechanical characteristics of the pixel substrate 31 and an increase in manufacturing cost due to the processing.

The height of the space 611 (the length in the vertical direction in FIG. 1) is, for example, about the same as the thickness of the seal portion 14, preferably about 10 μm or more and 150 μm or less, and more preferably about 15 μm or more and 100 μm or less. preferable.

The depth d of the recess 612 (see FIG. 1) is not particularly limited, but is preferably 1 μm or more and 500 μm or less, more preferably 2 μm or more and 400 μm or less, and 3 μm or more and 300 μm or less. Is even more preferable. By setting the depth d of the recess 612 within the above range, the volume of the liquid pool 61 can be reduced while minimizing the influence of the presence of the recess 612 on the mechanical and optical characteristics of the electrophoresis display device 1. It can be fully expanded. As a result, the frame can be narrowed without impairing the reliability of the electrophoresis display device 1.

Further, although the depth d of the recess 612 varies depending on the thickness of the first substrate 11, it is preferably 3% or more and 80% or less of the thickness of the first substrate 11, and 5% or more and 60% or less. More preferably, it is more preferably 7% or more and 50% or less. As a result, it is possible to minimize the deterioration of the mechanical properties of the first substrate 11 while sufficiently securing the volume of the recess 612.

On the other hand, the width R of the liquid pool portion 61 is not particularly limited because it varies depending on, for example, the size of the display area E, but as an example, it is preferably about 50 μm or more and 5000 μm or less, and preferably about 100 μm or more and 3000 μm or less. More preferred. As a result, a sufficient amount of the electrophoresis dispersion liquid 70 can be stored, and the occupancy ratio of the liquid pool portion 61 with respect to the width B of the frame portion 5 is sufficiently suppressed. Therefore, the degree of freedom in designing the electrophoresis display device 1 Can be easily increased.

(First modification)
Here, FIGS. 3 to 5 are cross-sectional views showing a first modification of the insulating layer 32 and the recess 612 shown in FIG. 1, respectively. In the following description, the differences between FIGS. 1 and 3 to 5 will be mainly described, and the same items as in FIG. 1 will be omitted. Further, with respect to FIGS. 3 to 5, the same reference numerals are given to the same configurations as those in FIG.

The insulating layer 32 shown in FIG. 3 is composed of a three-layer laminated body. Specifically, the insulating layer 32 shown in FIG. 3 includes a first insulating layer 321 located on the pixel substrate 31 side, a second insulating layer 322 laminated on the first insulating layer 321 and a second insulating layer 322 laminated on the first insulating layer 321. The three insulating layers 323 and the like are provided. The recess 612 is formed so as to penetrate all of these three layers.

On the other hand, the insulating layer 32 shown in FIG. 4 is also composed of a three-layer laminated body, but the configuration of the recess 612 is different from that of FIG. That is, the recess 612 shown in FIG. 4 penetrates the third insulating layer 323 and the second insulating layer 322, but does not penetrate the first insulating layer 321. Therefore, the recess 612 shown in FIG. 4 is shallower than the recess 612 shown in FIG. 3 by the thickness of the first insulating layer 321.

Further, the insulating layer 32 shown in FIG. 5 is also composed of a laminated body of three layers, but the structure of the recess 612 is different from that of FIGS. 3 and 4. That is, the recess 612 shown in FIG. 5 penetrates the third insulating layer 323, but does not penetrate the second insulating layer 322 and the first insulating layer 321. Therefore, the recess 612 shown in FIG. 5 is shallower than the recess 612 shown in FIG. 4 by the thickness of the second insulating layer 322.

The depth of the recess 612 can be easily adjusted only by forming the insulating layer 32 into a laminated structure and including a portion where each insulating layer constituting the laminated structure is not partially provided. be able to. Therefore, the volume of the liquid pool portion 61 can be easily adjusted without performing complicated processing or the like.

In the case of this first modification, examples of the constituent material of the first insulating layer 321 include silicon oxide and the like. Further, examples of the constituent material of the second insulating layer 322 include silicon nitride and the like. Further, examples of the constituent material of the third insulating layer 323 include various resin materials. These constituent materials are appropriately selected, for example, at the request of an electric circuit provided inside the insulating layer 32.

The recesses 612 shown in FIGS. 3 to 5 as described above also have the same effect as the recesses 612 shown in FIG.

(Second modification)
6 and 7 are plan views showing a second modification of the recess 612 shown in FIG. 1, respectively. In the following description, the differences between FIG. 1 and FIGS. 6 and 7 will be mainly described, and the description of the same items as in FIG. 1 will be omitted. Further, with respect to FIGS. 6 and 7, the same reference numerals are given to the same configurations as those in FIG.

The recess 612 shown in FIG. 6 has a frame shape surrounding the display area E when the first substrate 11 is viewed in a plan view, and is provided intermittently. That is, the recess 612 is composed of intermittently provided grooves. By forming the recess 612 intermittently in this way, the volume of the liquid pool portion 61 can be easily adjusted and formed only by appropriately changing the ratio of the lengths for forming the recess 612. Therefore, the liquid pool portion 61 having a target volume can be easily formed.

On the other hand, the recess 612 shown in FIG. 7 has a frame shape surrounding the display area E and is continuously provided when the first substrate 11 is viewed in a plan view. That is, the recess 612 is composed of continuously provided grooves. By continuously forming the recesses 612 in this way, the volume of the liquid pool portion 61 can be expanded not only in a part but also in the whole. Therefore, even if the location where the surplus portion of the electrophoresis dispersion liquid 70 is generated is spatially biased, the surplus portion can be easily received by the liquid sump portion 61 and can be easily distributed to the entire liquid sump portion 61.

Further, the recess 612 shown in FIG. 7 is further provided in double inside and outside. By forming the recess 612 twice in this way, the width of one recess 612 can be narrowed. As a result, the decrease in mechanical strength of the first substrate 11 due to the provision of the recess 612 can be minimized.

The inner recess 612 and the outer recess 612 may have a depth d equal to or different from each other. When they are different from each other, for example, the depth d can be made different as shown in FIGS. 3 to 5.

Further, the inner recess 612 and the outer recess 612 may have the same width or different widths from each other.

Further, the depth d and the width may be constant over the entire circumference thereof, or may be changed in the middle. For example, the width of the long side portion may be relatively narrow and the width of the short side portion may be relatively wide, or vice versa.

Further, the inner recess 612 and the outer recess 612 may communicate with each other at at least one place.

Further, at least one of the inner recess 612 and the outer recess 612 may be formed intermittently as shown in FIG.
The recesses 612 are not limited to double, and may be provided in multiple layers of triple or more.

The recess 612 shown in FIGS. 6 and 7 as described above also has the same effect as the recess 612 shown in FIG.

<Manufacturing method of electrophoresis display device>
Next, a method of manufacturing the electrophoresis display device shown in FIG. 1 will be described.

8 to 11 are diagrams for explaining a method of manufacturing the electrophoresis display device shown in FIG. 1, respectively.

[1] First, as shown in FIG. 8, the first substrate 11 is prepared. The first substrate 11 is a laminate of a pixel substrate 31 and an insulating layer 32, and the insulating layer 32 is formed with a recess 612 that is partially defective.

Next, as shown in FIG. 8, the pixel electrode 21, the partition wall member 35, and the seal portion 14 are arranged on the upper surface of the first substrate 11. Then, the electrophoresis dispersion liquid 70 is supplied to the region surrounded by the partition member 35. The supplied electrophoresis dispersion liquid 70 has a dome shape in which the central portion is raised due to surface tension. At this time, the supply amount of the electrophoresis dispersion liquid 70 is an amount that fills at least the space surrounded by the partition wall member 35 when the first substrate 11 and the second substrate 12 are bonded together.

[2] Next, as shown in FIG. 9, the second substrate 12 provided with the bonding layer 62 and the common electrode 22 is laminated so as to face the first substrate 11. As a result, the bonding layer 62 is in contact with the electrophoresis dispersion liquid 70, and the second substrate 12 is in contact with the sealing portion 14. As a result, a space 611 located between the partition wall member 35 and the seal portion 14 in a plan view and provided between the first substrate 11 and the second substrate 12 is formed. Then, the liquid pool portion 61 is formed by the recess 612 and the space 611 described above.

[3] Next, the first substrate 11 and the second substrate 12 are brought close to each other. As a result, the partition member 35 bites into the joint layer 62. Further, the seal portion 14 is compressed in the thickness direction. As a result, the first substrate 11 and the second substrate 12 are fixed to each other via the bonding layer 62 and the sealing portion 14 (see FIG. 10).

At the same time, the electrophoretic dispersion liquid 70 flows out beyond the partition wall member 35 due to the proximity of the first substrate 11 and the second substrate 12. Since the electrophoretic dispersion liquid 70 that has flowed out is dammed by the seal portion 14, it is stored in the liquid pool portion 61 as shown in FIG. As a result, it is possible to prevent the electrophoresis dispersion liquid 70 from flowing out to the outside.

Further, when bubbles are involved in the electrophoresis dispersion liquid 70, the bubbles can be expelled to the outside by bringing the first substrate 11 and the second substrate 12 close to each other. The expelled air bubbles stay in the liquid pool portion 61. As a result, it is possible to prevent the bubbles from being located in the display area E (see FIG. 1), and to prevent the bubbles from hindering the display of the image.

[4] Next, as shown in FIG. 11, a sealing portion 63 is provided on the outside of the sealing portion 14. As a result, the electrophoresis display device 1 is obtained. When the desired adhesive force between the first substrate 11 and the second substrate 12 is secured only by the sealing portion 14, it is not necessary to provide the sealing portion 63.

<< Second Embodiment >>
Next, the second embodiment of the present invention will be described.

FIG. 12 is a cross-sectional view showing a second embodiment of the electrophoresis display device of the present invention. In the following description, for convenience of explanation, the upper side in FIG. 12 will be referred to as “upper” and the lower side will be referred to as “lower”.

Hereinafter, the second embodiment will be described, but in the following description, the differences from the first embodiment will be mainly described, and the description of the same matters will be omitted. The same reference numerals are given to the same configurations as those of the first embodiment described above.

The recess 612 (groove) according to the present embodiment is the same as the recess 612 according to the first embodiment, except that the recess 612 (groove) is formed so as to penetrate the insulating layer 32 and also enter the pixel substrate 31.

That is, the recess 612 shown in FIG. 12 includes a portion where the upper surface of the pixel substrate 31 is partially recessed in addition to the portion where the insulating layer 32 is not partially provided. As a result, the recess 612 shown in FIG. 12 is deeper than the recess 612 shown in FIG. 1 by the amount including the portion formed by denting the upper surface of the pixel substrate 31. Therefore, the volume of the liquid sump portion 61 shown in FIG. 12 can be expanded as compared with that of the liquid sump portion 61 shown in FIG. 1 without widening the width of the liquid sump portion 61. As a result, a liquid pool portion 61 capable of storing a larger amount of the electrophoresis dispersion liquid 70 can be obtained. Therefore, for example, when the display area E is enlarged, the electrophoresis dispersion liquid generated at the time of production is obtained. Even if the surplus of 70 becomes large, the liquid pool portion 61 capable of storing the surplus can be obtained.

Therefore, the electrophoresis display device 1 according to the present embodiment has a narrow frame and a high degree of design freedom even when the display area E is enlarged.

The method for forming the recess 612 with respect to the pixel substrate 31 is not particularly limited, and examples thereof include a machining method, a laser processing method, an electron beam processing method, and an etching method. Of these, the wet etching method is preferably used. According to this method, the bottom surface of the formed recess 612 has a rounded shape. As a result, it becomes difficult for stress to concentrate in the corners of the recess 612, and it is possible to suppress a decrease in the mechanical strength of the pixel substrate 31 due to the formation of the recess 612.
Also in the second embodiment as described above, the same effect as that of the first embodiment can be obtained.

<< Third Embodiment >>
Next, a third embodiment of the present invention will be described.

FIG. 13 is a cross-sectional view showing a third embodiment of the electrophoresis display device of the present invention. In the following description, for convenience of explanation, the upper side in FIG. 13 will be referred to as “upper” and the lower side will be referred to as “lower”.

Hereinafter, the third embodiment will be described, but in the following description, the differences from the first embodiment will be mainly described, and the description of the same matters will be omitted. The same reference numerals are given to the same configurations as those of the first embodiment described above.

The recess 612 (groove) according to the present embodiment is the same as the recess 612 according to the first embodiment, except that the recess 612 (groove) is formed not on the first substrate 11 side but on the second substrate 12 side.

That is, the recess 612 shown in FIG. 13 is composed of a portion in which the lower surface of the facing substrate 41 (second substrate 12) is recessed upward. Therefore, the volume of the liquid pool portion 61 shown in FIG. 13 can be expanded without increasing the width as compared with the case where the liquid pool portion 61 is composed of only the space 611.

Therefore, the electrophoresis display device 1 according to the present embodiment has a narrow frame and a high degree of design freedom.

Further, as a result of the liquid pool portion 61 being expanded to the display surface side (upper side of FIG. 13) as compared with the first embodiment, the user looking at the display area E will see the seal portion 14 located in the oblique direction. Then, the seal portion 14 is hidden behind the liquid pool portion 61. As a result, color unevenness and the like exhibited by the seal portion 14 are covered by the liquid pool portion 61, and the discomfort felt by the user by the seal portion 14 can be suppressed. Examples of the color unevenness exhibited by the seal portion 14 include unevenness in the bonding state at the interface between the seal portion 14 and the second substrate 12.

In addition, the relationship between the recess 612 and the first substrate 11 in each of the above-described embodiments is the same as the relationship between the recess 612 and the second substrate 12 in the present embodiment.

The method for forming the recess 612 with respect to the facing substrate 41 is not particularly limited, and examples thereof include a machining method, a laser processing method, an electron beam processing method, and an etching method. Of these, the wet etching method is preferably used. According to this method, the bottom surface of the formed recess 612 has a rounded shape. As a result, it becomes difficult for stress to concentrate in the corners of the recess 612, and it is possible to suppress a decrease in the mechanical strength of the facing substrate 41 due to the formation of the recess 612.
Also in the third embodiment as described above, the same effect as that of the first embodiment can be obtained.

(Electronics)
Next, an embodiment of the electronic device of the present invention will be described. The electronic device according to the present embodiment includes the electrophoresis display device according to the embodiment.

FIG. 14 is a front view of a wristwatch to which an embodiment of the electronic device of the present invention is applied.
The wristwatch 401 (embodiment of the electronic device of the present invention) shown in FIG. 14 includes a watch case 402 and a pair of bands 403 connected to the watch case 402. An electrophoresis display device 405 (the embodiment of the electrophoresis display device of the present invention), a second hand 421, a minute hand 422, and an hour hand 423 are provided on the front surface of the watch case 402. A crown 410 as an operator and an operation button 411 are provided on the side surface of the watch case 402.

FIG. 15 is a side sectional view of the wristwatch shown in FIG.
A housing portion 402A is provided inside the watch case 402 shown in FIG. The movement 404 and the electrophoresis display device 405 are housed in the housing portion 402A. A transparent cover 407 made of glass or resin is provided on one end side (front side of the watch) of the accommodating portion 402A. A back cover 409 is screwed onto the other end side (back side of the watch) of the accommodating portion 402A via a packing 408, and the watch case 402 is sealed by the back cover 409 and the transparent cover 407.

The movement 404 has a hand movement mechanism (not shown) to which an analog pointer including a second hand 421, a minute hand 422, and an hour hand 423 is connected. This hand movement mechanism rotates and drives the analog pointer and functions as a time display unit that displays a set time.

The electrophoresis display device 405 is arranged on the front side of the watch of the movement 404 and constitutes the display unit of the wristwatch 401. The display surface of the electrophoresis display device 405 has a circular shape here, but may have other shapes such as a regular octagonal shape and a hexagonal shape. A through hole 405A that penetrates the front and back surfaces of the electrophoresis display device 405 is formed in the central portion of the electrophoresis display device 405. The shafts of the second wheel 424, the second wheel 425, and the cylinder wheel 426 of the hand movement mechanism (not shown) of the movement 404 are inserted into the through hole 405A. A second hand 421, a minute hand 422, and an hour hand 423 are attached to the tip of each shaft.

The wristwatch 401 may be configured by displaying various information on the electrophoresis display device 405 without mounting an analog pointer.

The electronic device of the present invention is applied to other than watches.
FIG. 16 is a perspective view showing the configuration of an electronic paper to which an embodiment of the electronic device of the present invention is applied.

The electronic paper 500 shown in FIG. 16 includes a display unit 501 (the embodiment of the electrophoresis display device of the present invention). The electronic paper 500 is flexible and includes a body 502 made of a rewritable sheet having the same texture and flexibility as conventional paper.

FIG. 17 is a perspective view showing the configuration of an electronic notebook to which an embodiment of the electronic device of the present invention is applied.

The electronic notebook 600 shown in FIG. 17 is formed by bundling a plurality of electronic papers 500 shown in FIG. 16 and sandwiching them between covers 601. The cover 601 includes display data input means (not shown) for inputting display data sent from, for example, an external device. As a result, the display contents can be changed or updated while the electronic papers are bundled according to the display data.

Electronic devices such as the wristwatch 401, electronic paper 500, and electronic notebook 600 as described above include the electrophoresis display device of the present invention. As a result, the effect of narrowing the frame can be enjoyed even if the liquid pool portion is provided inside. As a result, these electronic devices have high reliability and a high degree of design freedom.

Although the electrophoresis display device and the electronic device of the present invention have been described above based on the illustrated embodiments, the present invention is not limited thereto.

For example, in the electrophoresis display device and the electronic device, the configuration of each part of the embodiment can be replaced with an arbitrary configuration having the same function, or any other configuration can be added. .. Further, two or more of the above embodiments may be combined. That is, the recesses may be formed on both the first substrate side and the second substrate side.

1 ... Electrophoresis display device, 1A ... Back plane, 1B ... Front plane, 5 ... Frame part, 7 ... Electrophoresis layer, 11 ... First substrate, 12 ... Second substrate, 14 ... Seal part, 21 ... Pixel electrode, 22 ... common electrode, 31 ... pixel substrate, 32 ... insulating layer, 34 ... pixel, 35 ... partition member, 41 ... opposed substrate, 61 ... liquid pool, 62 ... bonding layer, 63 ... sealing part, 70 ... electrophoresis Dispersion, 71 ... Electrophoretic particles, 72 ... Dispersion medium, 321 ... First insulating layer, 322 ... Second insulating layer, 323 ... Third insulating layer, 401 ... Watch, 402 ... Watch case, 402A ... Storage, 403 ... Band, 404 ... Movement, 405 ... Electrophoretic display, 405A ... Through hole, 407 ... Transparent cover, 408 ... Packing, 409 ... Back cover, 410 ... Crown, 411 ... Operation buttons, 421 ... Second hand, 422 ... Minute hand, 423 ... hour hand, 424 ... second wheel, 425 ... second wheel, 426 ... cylinder wheel, 500 ... electronic paper, 501 ... display unit, 502 ... main body, 600 ... electronic notebook, 601 ... cover, 611 ... space, 612 ... recess , E ... Display area

Claims (4)

A partition member arranged between the first substrate and the second substrate,
The electrophoretic dispersion liquid arranged in the pixels partitioned by the partition member and
A seal portion located outside the display area including the plurality of pixels and arranged between the first substrate and the second substrate.
A liquid pool portion provided between the display area and the seal portion,
Have,
The liquid pool portion is configured to include a recess provided in the first substrate.
The first substrate includes a pixel substrate and an insulating layer provided on the electrophoresis layer side of the pixel substrate.
An electrophoresis display device, wherein the recess includes a portion where the insulating layer is not partially provided. The electrophoresis display device according to claim 1, wherein the recess is composed of a groove provided continuously or intermittently. The electrophoresis display device according to claim 1 or 2, wherein the depth of the recess is 1 μm or more and 500 μm or less. An electronic device comprising the electrophoresis display device according to any one of claims 1 to 3.

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