JP5804401B2 - Reflective display device - Google Patents

Description

  The present invention relates to a reflective display device applied to electronic paper and the like.

  Recently, as a reflective display device, an electrophoretic display device using an electrophoretic material as an electroresponsive material contained in a display medium has been widely used. An electrophoretic display device is a device that displays information by using electrophoretic migration, that is, particle movement, of an electrophoretic body (usually electrophoretic particles) in air or in a solvent. In general, an electrophoretic state is controlled by applying an electric field between two substrates, thereby realizing a desired display. As the electrophoretic body, charged powder as well as charged particles can be used. In that case, the charged powder electrophoreses in the gas.

  In recent years, the electrophoretic display device has attracted attention especially as an electronic paper. When applied as an electronic paper, it is possible to enjoy advantages such as visibility at the printed matter level (easy for eyes), ease of information rewriting, low power consumption, and light weight.

  However, in an electrophoretic display device, display defects, particularly a decrease in contrast, may occur due to sedimentation or uneven distribution of particles or powder. In order to prevent this phenomenon, it is used to form partition walls between the upper and lower electrode substrates and divide the migration space of the particles and powder to be electrophoresed, that is, the movement space into minute spaces. This minute space is called a cell. In each cell, ink or gas (display medium) containing an electrophoretic body is enclosed. For example, JP 2005-24868 A and JP 2011-524548 A disclose a conventional example of such an electrophoretic display device.

Summary of the Invention

  The present inventor has obtained the following knowledge while earnestly studying the method of forming the partition wall.

  In the reflective display device as described above, a common translucent electrode that covers at least the display region, a partition wall that partitions a plurality of cells, and a periodic pattern are arranged between one substrate and the other substrate. The plurality of pixel electrodes formed are provided in this order when viewed from the one substrate side toward the other substrate side. And the desired display is implement | achieved by controlling the electrophoretic state of the electroresponsive material contained in a display medium for every cell. The pixel electrode pattern is a matrix-like periodic alignment pattern that generally forms a rectangle as a whole. The partition walls are also generally formed in a pattern having periodicity.

  Here, when a plurality of periodic patterns are rotated and superimposed with respect to each other, as shown in FIG. 11, an area where the pattern overlap is sparse and a area where the pattern overlap is formed are formed. A striped pattern may occur. Such a striped pattern in which a plurality of periodic patterns are superimposed is called moire or interference fringe.

  The inventor of the present application is that in a reflective display device that observes a pixel electrode through a partition wall, it is practical that the display quality of the display device is impaired due to the moire appearing when the partition wall pattern and the pixel electrode pattern overlap. It was found that this could be a problem.

  The present invention has been made based on such circumstances, and an object of the present invention is to provide a reflective display device in which the occurrence of moire is suppressed and a method for manufacturing the same.

  In the present invention, a display medium containing at least one kind of electrically responsive material is sealed between two opposing substrates each having an electrode formed thereon, and a predetermined electric field is applied between the two substrates. A reflective display device that displays a desired display when the one substrate has a light-transmitting property, and a common area that covers at least a display region between the one substrate and the other substrate. A translucent electrode, a partition partitioning a plurality of cells in a periodic pattern, and a plurality of pixel electrodes arranged in a periodic pattern are directed from the one substrate side to the other substrate side. The barrier rib pattern is a pattern in which hexagonal unit patterns are regularly arranged, and the pixel electrode pattern is regularly arranged in rectangular unit patterns. The one substrate is a pattern One of the lines connecting the opposing corners of each cell partitioned by the partition wall extends in parallel to one of the edge portions of each pixel electrode when viewed from the side toward the other substrate side It is a reflection type display device characterized by having a relationship of being rotated by 10 ° to 20 ° with respect to the substrate.

  Preferably, the partition pattern is a pattern in which regular hexagonal unit patterns are regularly arranged.

  Alternatively, in the present invention, a display medium containing at least one kind of electrically responsive material is sealed between two opposing substrates each having an electrode formed thereon, and a predetermined electric field is interposed between the two substrates. Is a reflective display device that displays a desired display when given, and one substrate has translucency, and covers at least a display region between the one substrate and the other substrate. A common translucent electrode, partition walls that partition a plurality of cells, and a plurality of pixel electrodes arranged in a periodic pattern are viewed in a direction from the one substrate side toward the other substrate side. The pixel electrode pattern is a pattern in which rectangular unit patterns are regularly arranged, and viewed from the one substrate side toward the other substrate side, At least some of the branch points of the partition wall are six When the unit pattern of the shape is regularly arranged as a reference pattern, it exists within a predetermined distance starting from the branch point of the reference pattern, and does not overlap with the branch point of the reference pattern, The partition wall and the pixel electrode are any one of lines connecting opposing branch points in each unit pattern of the reference pattern of the partition wall when viewed from the one substrate side toward the other substrate side. Is a reflection type display device characterized by being arranged so as to be rotated by 5 ° to 25 ° with respect to a line extending in parallel with one of the edge portions of the pixel electrode.

  Preferably, the reference pattern is a pattern in which regular hexagonal unit patterns are regularly arranged.

  In the present invention, a display medium including at least one or more kinds of electrically responsive materials is sealed between two opposing substrates on which at least one of them has a light-transmitting property and each has electrodes formed thereon. A reflective display device in which the display medium displays a desired display when a predetermined electric field is applied between the two substrates, wherein one of the substrates has translucency, A common translucent electrode that covers at least the display region, a partition wall that partitions a plurality of cells, and a plurality of pixel electrodes arranged in a periodic pattern between the substrate and the other substrate, A reflective display characterized in that it is provided in this order when viewed from the side of the substrate toward the side of the other substrate, and at least a part of the partition is formed in an aperiodic pattern. Device.

  In particular, the partition and the translucent electrode or the other element on the one substrate or the one substrate are in contact with each other, and the partition and the pixel electrode or the other substrate are in contact with each other. When other elements or the other substrate are in contact with each other, the effect of suppressing the occurrence of the moire phenomenon is remarkable.

  Preferably, the number of partition walls extending from each branch point of the partition walls is 3 or 4.

  Preferably, when viewed in the direction from the one substrate to the other substrate, at least a part of the branch points of the partition wall is the reference pattern when unit patterns having the same shape are regularly arranged as a reference pattern. It exists within the range of a predetermined distance starting from the branch point of the pattern, and does not overlap with the branch point of the reference pattern.

  Preferably, when viewed in the direction from the one substrate to the other substrate, at least a part of the branch points of the partition wall is the reference pattern when unit patterns having the same shape are regularly arranged as a reference pattern. Associating each branch point of the pattern with each lattice point of the lattice pattern having a pitch corresponding to the reference pattern, and expanding or reducing each row or each column of the lattice pattern in the direction of the row or the direction of the column Accordingly, the grid points of the grid pattern are moved, and the branch points associated with the grid points are also moved in correspondence with the movement of the grid points.

  Preferably, when viewed in the direction from the one substrate to the other substrate, at least some of the branch points of the partition walls, when unit patterns having the same shape are regularly arranged as a first reference pattern, Each branch point of the first reference pattern is associated with each lattice point of the lattice pattern having a pitch corresponding to the first reference pattern, and each row or each column of the lattice pattern is defined as the direction of the row or the direction of the column. The grid point of the grid pattern is moved by enlarging or reducing the grid point, and each branch point associated with the grid point is also moved corresponding to the movement of the grid point. It exists within the range of a predetermined distance starting from the branch point, and does not overlap with the branch point of the second reference pattern.

FIG. 1 is a cross-sectional view schematically showing a configuration of a reflective display device according to a first embodiment of the present invention. FIG. 2 is a flowchart schematically showing a manufacturing method of the reflective display device according to the first embodiment of the present invention. FIG. 3 is a diagram schematically showing an example of the partition wall forming step. FIG. 4 is a view for explaining a method of forming a partition wall according to the embodiment shown in FIG. Specifically, FIG. 4 (a) is a diagram showing a partition pattern in which hexagonal unit patterns are regularly arranged, and FIG. 4 (b) is a periodic pattern shown in FIG. 4 (a). It is a figure which shows the partition formed so that the cell of this may be divided. FIG. 5 is a diagram for explaining the definition of the width of the top surface of the partition wall. FIG. 6 is a diagram schematically showing an example of the adhesive layer forming step. FIG. 7 is a diagram schematically showing an example of the display medium arranging step. FIG. 8 is a schematic view for explaining the function of the conductive paste. FIG. 9 is a diagram showing a periodic pattern of pixel electrodes in which rectangular unit patterns are regularly arranged. FIG. 10 is a cross-sectional view showing a state in which the top surface of the partition wall of one substrate and the pixel electrode of the other substrate are arranged to face each other in the counter substrate arranging step. FIG. 11 is a diagram for explaining the mechanism of moiré expression. FIG. 12 shows the pattern of the pixel electrode and the pattern of the partition wall due to the difference in the rotation angle between the line extending in parallel with the edge of the pixel electrode and the line connecting the opposing corners in the cell partitioned by the partition wall. It is a figure for demonstrating the difference in the way of the formation of the density of the overlap. Specifically, FIG. 12A shows 0 ° and FIG. 12B shows 5 ° with respect to a line connecting parallel corners of each cell partitioned by the partition walls extending in parallel with the edge of the pixel electrode. 12 (c) is rotated by 10 °, FIG. 12 (d) is rotated by 15 °, FIG. 12 (e) is rotated by 20 °, FIG. 12 (f) is rotated by 25 °, and FIG. FIG. FIG. 13 shows the difference in the appearance of moire due to the difference in the rotation angle between the line extending in parallel with the edge of the pixel electrode and the line connecting the opposing corners in the cell partitioned by the partition walls. It is a figure for demonstrating. Specifically, FIG. 13A shows 0 ° or 30 ° with respect to a line connecting parallel corners of each cell partitioned by the partition walls extending in parallel with the edge of the pixel electrode, and FIG. Of moiré in a state where the angle is 5 °, FIG. 13 (c) is 10 °, FIG. 13 (d) is 15 °, FIG. 13 (e) is 20 °, and FIG. It is a figure for demonstrating the mode of. FIG. 14 is a diagram for explaining a method of forming a partition according to the second embodiment of the present invention. Specifically, FIG. 14A shows a reference pattern, and FIG. 14B shows a partition pattern formed on the basis of the reference pattern shown in FIG. FIG. 15 is a diagram for explaining the creation conditions and the evaluation results of the display devices of the example of the present invention and the comparative example. FIG. 16 is a diagram for explaining a method of forming a final partition pattern from a reference pattern in the partition formation step. Specifically, FIG. 16A is a diagram for explaining a method of forming a final partition wall pattern using a honeycomb-shaped reference pattern in which regular hexagonal unit patterns are regularly arranged. FIG. 16B is a diagram for explaining a method of forming a final partition pattern using a square lattice reference pattern formed by regularly arranging square unit patterns. FIG. 17 is a diagram for explaining the degree of randomness when the branch point of the reference pattern is randomly displaced. FIG. 18 is a diagram for explaining a difference in final partition wall pattern due to a difference in randomness shown in FIG. Specifically, FIG. 18A is a diagram showing a final partition pattern in the case of the randomness R1 shown in FIG. 17, and FIG. 18B is a final partition wall in the case of the randomness R2 shown in FIG. FIG. 18 (c) is a diagram showing a final partition pattern in the case of the randomness R3 shown in FIG. 17, and FIG. 18 (d) is a case of the randomness R4 shown in FIG. It is a figure which shows the last partition pattern. FIG. 19 is a diagram for explaining the mechanism of the occurrence of the moire phenomenon. FIG. 20 is a diagram for explaining the minimum moving distance of the partition wall for effectively suppressing the occurrence of the moire phenomenon. Specifically, in FIG. 20A, the partition walls are arranged so that the partition wall center line equally dividing the partition line width coincides with the inter-electrode center line dividing the interval between the opposing edge portions of the adjacent pixel electrodes. FIG. 20B is a diagram showing a state of being arranged on the substrate on the side, and FIG. 20B is a position where the partition wall of FIG. 20A does not overlap with the region between the pixel electrodes, that is, one pixel of the partition wall. It is a figure which shows a mode that the edge part by the side of an electrode was displaced so that it might correspond with the edge part by the side of the area | region between the said pixel electrodes of the other pixel electrode. FIG. 21 is a diagram for explaining the mechanism of occurrence of rough unevenness. FIG. 22 is a plan view showing a difference in display shade on a panel in which rough unevenness occurs. FIG. 23 is a diagram for explaining the definition of the cell area distribution rate. FIG. 24 is a diagram for explaining a method of forming the partition based on the final partition pattern. FIG. 25 is a plan view showing an example of a partition formed in the partition formation step according to the 3-1 embodiment. FIG. 26 is a plan view showing another example of the barrier ribs formed in the barrier rib forming step according to the 3-1 embodiment. FIG. 27 is a diagram for explaining a method of forming a final pattern of barrier ribs in the method of manufacturing a reflective display device according to the third to second embodiments of the present invention. FIG. 28 is a diagram showing a partition pattern according to another embodiment of the present invention. FIG. 29 is a diagram showing a partition pattern of a comparative example of the present invention. FIG. 30 is a diagram showing a partition pattern of another comparative example of the present invention.

  FIG. 1 is a cross-sectional view schematically showing a configuration of a reflective display device according to a first embodiment of the present invention. In the reflective display device according to the present embodiment, at least one of the electrical responses is provided between the two opposing substrates 11 and 16 on which at least one of them has translucency and the electrodes 111 and 161 are respectively formed. A display medium 13 containing a conductive material is enclosed, and the display medium 13 performs a desired display when a predetermined electric field is applied between the two substrates 11 and 16. Here, in the specification and claims of the present application, “translucent” means a property of transmitting light. In the present embodiment, the substrate (one substrate 11) arranged on the viewing side has a light-transmitting property such that the total light transmittance is 50% or more, preferably 80% or more, more preferably 90% or more. have.

  2 to 7, an electrode 111 is provided on the surface of one substrate 11, but the illustration of the electrode 111 is omitted. In the present embodiment, one substrate 11 is disposed on the viewing side, and the other substrate 16 is disposed on the non-viewing side.

  One substrate 11 includes a light-transmitting film such as polyethylene (PE), polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), or light-transmitting glass, and indium tin oxide (ITO). ), Zinc oxide (ZnO), tin oxide (SnO), or the like having a translucent electrode (translucent electrode) so as to cover at least the display region of one substrate 11 is typically used. obtain. Here, the “display area” refers to an area used for desired display in the reflective display device.

  The translucent electrode 111 can be formed by a coating method, sputtering, a vacuum deposition method, a CVD method, or the like. In the present embodiment, the translucent electrode 111 is formed as a common electrode for driving an active matrix.

  The thickness of one substrate 11 is preferably 10 μm to 1 mm. If it is thinner than 10 μm, the strength as a panel cannot be obtained and the risk of breakage increases. On the other hand, if it is thicker than 1 mm, the panel weight becomes too heavy and the handling becomes inconvenient and the cost also increases. Because. A suitable thickness range that is difficult to break and easy to handle is about 50 μm to 300 μm.

  One substrate 11 can be applied in either a roll shape or a sheet shape.

  As the other substrate 16, a substrate such as a resin film, a resin plate, glass, epoxy glass (glass epoxy) or the like can be used. The other substrate 16 may be a translucent base material. Furthermore, it may be an opaque base material that is translucent, but an opaque glass base material, resin film, resin plate, glass, epoxy glass with the other surface different from the electrode surface roughened. (Garaepo) or the like can be used. In the present embodiment, since the other substrate 16 is disposed at a position opposite to the viewing side, there is no necessity of having translucency. However, when the same physical properties as the one substrate 11 such as thermal expansion characteristics are required, a light-transmitting member similar to the one substrate 11 can be used.

  In the later step, a plurality of pixel electrodes 161 are provided on the surface of the other substrate 16 on the display medium side. In this embodiment, a pixel electrode corresponding to a TFT (Thin Film Transistor) layer for driving an active matrix is used as the pixel electrode 161.

  The thickness of the other substrate 16 is preferably 10 μm to 1 mm, similarly to the thickness of the one substrate 11. If it is thinner than 10 μm, the strength as a panel cannot be obtained and the risk of breakage increases. On the other hand, if it is thicker than 1 mm, the panel weight becomes too heavy and the handling becomes inconvenient and the cost also increases. Because. A suitable thickness range that is difficult to break and easy to handle is about 50 μm to 300 μm.

  The other substrate 16 can be applied in either a roll shape or a sheet shape.

<Method for manufacturing reflective display device>
FIG. 2 is a flowchart schematically showing a manufacturing method of the reflective display device according to the first embodiment of the present invention.

  FIG. 3 is a diagram schematically showing an example of the partition wall forming step. As shown in FIG. 3, first, a partition wall 12 is formed on the upper surface of one substrate 11 generally placed in a horizontal direction by, for example, photolithography (exposure by ultraviolet (UV) irradiation → development → firing). (Partition wall forming step: step (1) in FIG. 2). The partition wall 12 is a member that defines a plurality of cells to be described later.

  In the specification and claims of the present application, the “cell” means one substrate 11 and the other to prevent a display defect, particularly a decrease in contrast, due to sedimentation or uneven distribution of particles or powder. This means a minute migration space of electrophoretic particles or powder divided by the partition walls 12 formed between the substrates 16, that is, a movement space. The partition wall 12 may be formed on the side of the other substrate 16 on which the pixel electrode 161 is formed after a pixel electrode formation step described later.

  The partition wall 12 can be composed of an ultraviolet curable resin, a thermosetting resin, a room temperature curable resin, or the like. As a method for forming the partition wall 12, a mold transfer method such as embossing can be adopted in addition to the photolithography method. Further, a method of manufacturing a structure having a desired pattern as a partition and sticking the structure to one substrate 11 may be employed. The aperture ratio is preferably 70% or more, and particularly preferably 90% or more. The higher the aperture ratio, the wider the displayable area, so that high contrast can be obtained.

  The partition wall 12 is formed so as to partition a plurality of cells in a periodic pattern with respect to the virtual reference axis 125, and the pattern of the partition wall 12 is a pattern in which hexagonal unit patterns are regularly arranged. . Here, in the present specification and claims, the “unit pattern” is an individual pattern surrounding individual regions divided by the entire pattern. The “virtual reference axis” is an axis that is used as a reference when forming the partition 12, the pixel electrode 161 described later, or a reference pattern of the partition 12. For example, the longitudinal axis of each of the substrates 11 and 16. And an axis defined so as to have a positional relationship rotated by an arbitrary angle with respect to the longitudinal axis in a plan view of the substrate. The pattern of the partition wall 12 and the pixel electrode 161 or the reference pattern of the partition wall 12 is formed by regularly arranging unit patterns with respect to such a virtual reference axis.

  In the present embodiment, the pattern of the partition walls 12 is formed as a periodic honeycomb pattern in which regular hexagonal unit patterns are regularly arranged as shown in FIG. However, hexagons other than regular hexagons can be adopted as the shape of the unit pattern. The pattern of the partition wall 12 is a pattern formed by arranging the lines connecting two opposing corner portions of each regular hexagonal unit pattern so as to be parallel to the virtual reference axis 125 of the partition wall 12. For this reason, as shown in FIG. 4B, the partition wall 12 is arranged so that the line connecting the two opposing corners of each cell partitioned by the partition wall 12 is parallel to the virtual reference axis 125 of the partition wall 12. It is formed.

  The cell size (pitch) depends on the size of the display panel, but is 0.05 mm to 1 mm pitch, preferably 0.1 mm to 0.5 mm pitch. Here, the pitch means the distance between the center points of adjacent cells.

  The width of the top surface of the partition wall 12 is 9 μm to 50 μm, preferably 9 μm to 20 μm. 9 μm is the lower limit of the line width at which the partition wall 12 can be patterned without falling down. When the width of the top surface of the partition wall 12 is less than 9 μm, in a pattern in which the length of the partition wall 12 is 60 μm or more, at least a part of the partition wall 12 falls, peels off, or the separated partition wall 12 moves over the substrate. Or move. In that case, the function of preventing the movement of particles by the partition wall 12 is lost, and the display quality is deteriorated. On the other hand, the upper limit of 50 μm, which is the upper limit of the preferred range, is an upper limit at which the partition wall 12 is not too conspicuous when visually observed.

  Here, the definition of the width of the top surface of the partition wall 12 is shown in FIG. If the corners of the top surface are not rounded, the width of the top surface is defined as it is, as shown in FIGS. 5 (a) and 5 (b). On the other hand, when the corner of the top surface is rounded, it is understood as the width between the intersection lines of the extended surface of the top surface and the extended surface of the wall surface, as shown in FIG. 5 (c) and FIG. 5 (d). The As a measuring method for evaluation, one substrate 11 on which the partition wall 12 was formed was embedded in a curable resin, and a cross section of the partition wall 12 was cut out by a microtome (Daiwa Kogyo Kogyo Co., Ltd .: FX-801). Each width can be measured based on an image taken by a scanning electron microscope (SEM).

  The height of the partition wall 12 is 5 to 50 μm, preferably 10 to 50 μm. If the thickness is 5 μm or less, the amount of ink to be filled is small, and sufficient display characteristics, in particular, contrast cannot be obtained. On the other hand, if the thickness is 50 μm or more, the panel is too thick and the drive voltage increases excessively. From the viewpoint that good display characteristics can be obtained at a low driving voltage, a height in the range of 10 to 50 μm is preferable.

  Next, the adhesive layer 22 is formed on the partition wall 12 (adhesive layer forming step: step (2) in FIG. 2). In this adhesive layer forming step, a thermoplastic resin such as a polyester-based thermoplastic adhesive is formed with a thickness of 1 μm to 100 μm by, for example, a transfer method or a printing method. Preferably, it is formed with a thickness of 1 μm to 50 μm, particularly preferably with a thickness of 1 μm to 20 μm.

  Supplementing a specific description of an example of a typical thermal transfer method as a transfer method, as shown in FIG. 6, for example, a polyester-based thermoplastic adhesive having a thickness of 20 μm on a PET film as a substrate 21. A transfer sheet 20 on which an adhesive 221 is formed is prepared. Next, the transfer sheet 20 is arranged to face the one substrate 11 so that the surface of the adhesive 221 is arranged on the top surface of the partition wall 12 of the one substrate 11. In this state, one substrate 11 and the transfer sheet 20 are laminated at a normal temperature and a pressure of 1 kPa. After laminating, one substrate 11 was oriented such that the end of the partition wall 12 on the one substrate 11 side was positioned higher than the top surface of the partition wall 12 on the side opposite to the one substrate 11. In this state, the one substrate 11 and the transfer sheet 20 are heated for one minute at a temperature higher than the softening point or melting point of the adhesive 221, and then the transfer sheet 20 is peeled off. Thereby, an adhesive layer 22 of about 6 μm, for example, is formed on the partition wall 12.

  As the adhesive 221 for forming the adhesive layer 22, an adhesive using a thermoplastic material is preferable. It has a property of softening by heating and solidifying when cooled, and is plastic when repeated cooling and heating. Is a material that is reversibly maintained.

  When an adhesive made of a thermoplastic material is used as an adhesive layer, the solidified adhesive 221 on the transfer sheet substrate 21 is softened by heating to a temperature exceeding the softening temperature, and the partition 22 The adhesive 221 can be reliably thermally transferred only to the top surface. Further, since the adhesive 221 after thermal transfer is cooled to room temperature and solidified again, tackiness, i.e., stickiness, is eliminated. Further, since there is no tack, that is, stickiness, the display medium 13 filled in the cell does not adhere to the adhesive 221. Then, the adhesive 221 on the top surface of the partition wall 22 is heated again to a temperature exceeding the softening temperature to be softened, so that it has tack, that is, stickiness, so that it is securely bonded to the other substrate 16. . Since the adhesive 221 after being bonded to the other substrate 16 is not tacked again at room temperature, that is, has no stickiness, the display medium 13 is not bonded to the adhesive 221 again, and the display quality may be deteriorated. Nor.

  Specifically, thermoplastic base polymers such as ethylene-vinyl acetate copolymer, polyester, polyamide, polyolefin, polyurethane, natural rubber, styrene-butadiene block copolymer, styrene-isoprene block copolymer, styrene-ethylene. A resin mainly composed of a thermoplastic elastomer such as a butylene-styrene block copolymer or a styrene-ethylene-propylene-styrene copolymer, and a tackifier resin or a plasticizer is mainly used.

  In order to improve the adhesion between the partition wall 12 and the adhesive 221, the partition wall 12 may be subjected to a surface treatment by ultraviolet irradiation, plasma treatment, or the like, or a primer may be formed. Alternatively, a silane coupling agent may be added to the adhesive 221.

  Next, the ink 13 as a display medium is placed on one substrate 11 (display medium placement step: step (3) in FIG. 2). FIG. 7 is a diagram schematically showing an example of the display medium arranging step. Here, (1) the ink 13 is dropped from the dispenser 31 or the inkjet or die coat (ink dropping step), and (2) the ink 13 is made uniform in the surface by the applicator 32 or doctor blade, doctor knife, and central squeegee. It is applied (ink application process). The ink 13 may be disposed on the other substrate 16.

  As the display medium 13, a display medium containing at least one or more kinds of electrically responsive materials can be used. Examples of the electroresponsive material include a charged particle material and a liquid crystal material, and the charged particle material includes a so-called electrophoretic material in which colored particles such as white, black, and color move in response to an electric field, or two particles. There are materials typified by twist balls that are color-coded and rotated by an electric field, or nanoparticle materials that move by an electric field. On the other hand, the liquid crystal material includes a material for electrically controlling transmission and scattering known as PDLC (Polymer Dispersed Liquid Crystal), a material in which a liquid crystal is mixed with a dye, a cholesteric liquid crystal material, and the like. These materials that have electrical responsiveness and change optical characteristics need to be isolated into cells regardless of the type, and are subject to application of the present invention.

  Returning to FIG. 2, after the display medium placement step, a conductive paste application step is performed (conductive paste application step: step (4) in FIG. 2). FIG. 8 is a schematic view for explaining the function of the conductive paste. The conductive paste 14 is a metal paste such as a silver paste, and is applied to a predetermined position by, for example, a dispenser 41 or ink jet, tampo printing, pad printing, or stacking printing. As shown in FIG. 8, the conductive paste 14 functions as a wiring for applying a voltage to the other substrate 16. When a predetermined electric field (voltage) is applied between the translucent electrode 111 of one substrate 11 and the pixel electrode 161 of the other substrate 16, the electrically responsive material in the ink 13 as a display medium is driven, Desired information such as a character pattern is displayed. Thereafter, even if the electric field is no longer applied, the information display state is maintained until a new electric field is applied between the two substrates.

  Next, a plurality of pixel electrodes 161 are formed on the other substrate 16 in a periodic pattern with respect to the virtual reference axis 165 of the pixel electrode 161 (pixel electrode formation step: step (5) in FIG. 2). . In the present embodiment, the pattern of the pixel electrode 161 is a pattern in which rectangular unit patterns are regularly arranged in a matrix as shown in FIG. The pattern of the pixel electrode 161 is a pattern in which two opposing sides 161 a and 161 b of each unit pattern are arranged so as to be parallel to the virtual reference axis 165. For this reason, the plurality of pixel electrodes 161 are formed such that two opposing edges of each pixel electrode 161 are parallel to the virtual reference axis 165 of the pixel electrode 161.

  Returning to FIG. 2, one substrate 11 and the other substrate 16 are arranged such that the top surface of the partition wall 12 of one substrate 11 and the pixel electrode 161 of the other substrate 16 face each other. Thereafter, the adhesive layer 22 on the top surface of the partition wall 12 and the other substrate 16 are bonded while extruding excess ink exceeding the cell volume in the partition wall 12 (opposing substrate placement step: step (6) in FIG. 2). ). Thereby, the display medium (ink 13) is sealed in each cell.

  Furthermore, in the counter substrate arrangement step of the present embodiment, as shown in FIG. 10, the adhesive 221 transferred as the adhesive layer 22 is heated to obtain an adhesive force. Specifically, the partition wall 12 and the other substrate are softened by heating the adhesive 221 from the periphery to a temperature exceeding the softening temperature while applying a predetermined thermocompression bonding pressure (laminating pressure) by the laminator 91. 16 is bonded. However, other thermocompression bonding modes may be employed.

  Here, in the counter substrate placement step of the present embodiment, the occurrence of moire due to the periodic pattern of the partition walls 12 and the periodic pattern of the pixel electrodes 161 is suppressed between the one substrate 11 and the other substrate 16. Arranged so that. With reference to FIG. 11 thru | or FIG. 13, the arrangement | positioning relationship of the one board | substrate 11 and the other board | substrate 16 which the expression of a moire is suppressed is demonstrated.

  FIG. 11 is a diagram for explaining the mechanism of moiré expression. FIG. 12 shows the pattern of the pixel electrode and the pattern of the partition wall due to the difference in the rotation angle between the line extending in parallel with the edge of the pixel electrode and the line connecting the opposing corners in the cell partitioned by the partition wall. It is a figure for demonstrating the difference in the way of the formation of the density of the overlap. Specifically, FIG. 12A shows 0 ° and FIG. 12B shows 5 ° with respect to a line connecting parallel corners of each cell partitioned by the partition walls extending in parallel with the edge of the pixel electrode. 12 (c) is rotated by 10 °, FIG. 12 (d) is rotated by 15 °, FIG. 12 (e) is rotated by 20 °, FIG. 12 (f) is rotated by 25 °, and FIG. FIG. Here, the opposite corners in each cell mean every third corner of the hexagon. FIG. 13 shows the appearance of moiré due to the difference in the rotation angle between the line extending in parallel with the edge of the pixel electrode and the line connecting the opposing corners in the cell partitioned by the partition walls. It is a figure for demonstrating a difference. Specifically, FIG. 13A shows 0 ° or 30 ° with respect to a line connecting parallel corners of each cell partitioned by the partition walls extending in parallel with the edge of the pixel electrode, and FIG. Of moiré in a state where the angle is 5 °, FIG. 13 (c) is 10 °, FIG. 13 (d) is 15 °, FIG. 13 (e) is 20 °, and FIG. It is a figure for demonstrating the mode of.

  First, moire or moire is also referred to as interference fringe, and is a striped pattern that is visually generated due to a shift in the period when a plurality of regularly repeated patterns are superimposed. As shown in FIG. 11, when a plurality of periodic patterns are overlapped with each other while being rotated with respect to each other, a region where the overlap of the plurality of patterns is sparse and a region where the overlap is dense are formed. Due to the presence of a region where the overlapping of a plurality of patterns is sparse and a region where the pattern is dense, a visual striped pattern, that is, moire may occur.

  In order to suppress the appearance of moire due to the superposition of a plurality of patterns, it is only necessary that the regions where the overlap is sparse and the regions where the overlap is dense are formed so as to be sufficiently fine. Therefore, in the present embodiment, the one substrate 11 and the other substrate 16 are formed with sufficiently fine areas where the overlap of the pattern of the partition wall 12 and the pattern of the pixel electrode 161 is sparse and dense. Arranged so that.

  Referring to FIG. 12 and FIG. 13, one substrate 11 and the other in which the region where the pattern of the partition wall 12 and the pattern of the pixel electrode 161 are sparse and the region where the pattern is dense are formed are sufficiently fine. The arrangement relationship with the substrate 16 will be described.

  As shown in FIG. 12A, FIG. 12G, and FIG. 13A, the reference axis 125 of the partition wall 12 is a pixel when viewed from the one substrate 11 side toward the other substrate 16 side. When the electrode 161 is rotated by 0 ° or 30 ° with respect to the reference axis 165, that is, one of the lines connecting the opposite corners in each cell partitioned by the partition 12 is the edge of each pixel electrode 161. When there is a relationship of being rotated by 0 ° or 30 ° with respect to a line extending parallel to one of the portions, the occurrence of moire due to the overlap between the pattern of the partition wall 12 and the pattern of the pixel electrode 161 is most suppressed. . However, in this case, the pattern of the partition wall 12 and the pattern of the pixel electrode 161 need to be aligned with high accuracy.

  In the case where the pattern of the partition wall 12 and the pattern of the pixel electrode 161 are arranged so as to be rotated with respect to each other, FIGS. 12 (b) to 12 (f) and FIGS. 13 (b) to 13 (f). As shown in FIG. 4, when the rotation of the reference axis 125 of the partition 12 relative to the reference axis 165 of the pixel electrode 161 is 15 ° when viewed from the side of one substrate 11 toward the other substrate 16, that is, the partition When any of the lines connecting the opposing corners in each cell partitioned by 12 is in a relationship of being rotated by 15 ° with respect to a line 165 extending parallel to any of the edges of each pixel electrode 161. The area where the overlap of the two patterns is sparse and the area where the two patterns are dense are formed most finely. Further, when viewed in the direction from the one substrate 11 side toward the other substrate 16 side, if the rotation is within a range of 10 ° to 20 °, that is, the cells facing each other partitioned by the partition walls 12 are opposed. When one of the lines connecting the corners is arranged to be rotated by 10 ° to 20 ° with respect to the line 165 extending in parallel to one of the edges of each pixel electrode 161, the two patterns overlap. The sparse region and the dense region are formed sufficiently finely, and the occurrence of moire is suppressed to such a level that there is no practical problem.

  Therefore, in the present embodiment, in the counter substrate placement step, the one substrate 11 and the other substrate 16 have the partition wall 12 as viewed from the one substrate 11 side toward the other substrate 16 side. The reference axis 125 is parallel to the reference axis 165 of the pixel electrode 161, that is, one of the lines connecting the opposing corners in each cell partitioned by the partition 12 is parallel to one of the edges of each pixel electrode 161. The extended line 165 is rotated by 10 ° to 20 °.

  In the case where the partition wall formation step is performed after the pixel electrode formation step and the partition wall 12 is formed on the side of the other substrate 16 where the pixel electrode 161 is formed, the partition wall 12 extends from the partition wall 12 side to the other side. As viewed in the direction toward the substrate 16, the reference axis 125 of the partition wall 12 is one of the lines connecting the reference axes 165 of the pixel electrodes, that is, the connecting corners of each cell partitioned by the partition wall 12. Is formed by being rotated by 10 ° to 20 ° with respect to a line 165 extending parallel to one of the edges of each pixel electrode 161.

  After the counter substrate placement step, as shown in FIG. 2, the sheet is cut into a predetermined size by a cutting device 51 such as a guillotine, an upper blade slide device, a laser cutting device, or a laser cutter (cutting step: step (7) in FIG. 2). ), The manufacture of the desired reflective display device is completed.

  As described above, according to the present embodiment, both the partition wall 12 and the pixel electrode 161 are formed in a periodic pattern, but any one of the lines connecting the corners of each cell partitioned by the partition wall 12 Because of the relationship of being rotated by 10 ° to 20 ° with respect to a line 165 extending in parallel to one of the edge portions of the pixel electrode 161, the pattern of the partition wall 12 and the pixel electrode 161 and the region where the overlap of the pattern is sparse are dense. Can be formed sufficiently finely. As a result, it is possible to suppress the appearance of a visual striped pattern, that is, moiré, due to the sparse region and the dense region where the partition 12 and the pixel electrode 161 overlap.

  Moreover, the pattern of the partition 12 is a pattern in which regular hexagonal unit patterns are regularly arranged. Therefore, the expression of moire is effectively suppressed.

  Note that FIG. 12 has been described in the case where the partition pitch and the pixel electrode pitch are the same, but the same applies even when the partition pitch and the pixel electrode pitch are different.

  Next, with reference to FIG. 14, the manufacturing method of the reflective display apparatus by 2nd Embodiment by this invention is demonstrated. In the present embodiment, the method of forming the partition wall 12 is different from that of the first embodiment.

  With reference to FIG. 14, the formation method of the partition 12 by this Embodiment is demonstrated. FIG. 14 is a diagram for explaining a method of forming the partition wall 12 according to the second embodiment of the present invention. Specifically, FIG. 14 (a) is a diagram showing a reference pattern, and FIG. 14 (b) is a diagram showing a pattern of partition walls 12 formed on the basis of the reference pattern shown in FIG. 14 (a).

  In the partition forming step of the present embodiment, first, a reference pattern in which hexagonal unit patterns are regularly arranged with respect to the virtual reference axis 125 of the partition 12 is prepared. Here, in the present specification and claims, the “reference pattern” refers to a reference (when determining the shape of the partition wall 12 as viewed from the one substrate 11 side toward the other substrate 16 side). Or a position where the branch point is compared with the position of the branch point of the partition wall 12.

  In this embodiment, the reference pattern is formed as a periodic honeycomb pattern in which regular hexagonal unit patterns are regularly arranged as shown in FIG. However, hexagons other than regular hexagons can be adopted as the unit pattern shape of the reference pattern. Further, the reference pattern is a pattern formed by arranging a line connecting two opposing corner portions of each regular hexagonal unit pattern so as to be parallel to the virtual reference axis 125 of the partition wall 12. The pitch of the reference pattern is 0.05 mm to 1 mm, preferably 0.1 mm to 0.5 mm. Here, the “pitch” of the reference pattern means a distance necessary for moving adjacent unit patterns to overlap each other.

  Next, the branch point of the partition wall 12 is positioned within a predetermined distance range R starting from each branch point K of the reference pattern. The partition wall 12 is formed based on the position of the branch point of the partition wall 12 positioned in this way. In the present embodiment, the branch points of the partition walls 12 are randomly positioned within the predetermined distance range R described above, but may be regularly positioned within the predetermined distance range R. In this way, a pattern of the partition walls 12 as shown in FIG. 14B is formed. In the present embodiment, the range R of the predetermined distance is a length of a side extending from the branch point starting from each branch point K of the reference pattern formed by arranging regular hexagonal unit patterns. The distance range is less than half.

  According to the knowledge obtained by the present inventors, when the pattern of the partition wall 12 is a pattern as shown in FIG. 14B, when viewed from the one substrate 11 side toward the other substrate 16 side, The partition 12 and the pixel electrode 161 are 5 ° with respect to a line 165 in which any of the lines connecting the opposing branch points in each unit pattern of the reference pattern of the partition 12 extends parallel to any of the edges of the pixel electrode 161. When the two patterns are arranged relative to each other such that the two patterns are arranged in a relationship of being rotated by -25 °, the area where the overlap of the two patterns is sparse and the area where the density is dense are formed sufficiently finely, and moire is formed. Is suppressed to such an extent that there is no practical problem.

  Then, in the counter substrate placement step, when the one substrate 11 and the other substrate 16 are viewed from the one substrate 11 side toward the other substrate 16 side, the reference axis 125 of the partition wall 12 is the pixel electrode 161. The reference axis 165 is rotated by 5 ° to 25 °. Thereby, the partition wall 12 and the pixel electrode 161 are connected to each other in the unit pattern of the reference pattern of the partition wall 12 as viewed from the one substrate 11 side toward the other substrate 16 side. Any one of them is arranged so as to have a relationship of being rotated by 5 ° to 25 ° with respect to a line 165 extending parallel to any of the edges of the pixel electrode 161, and so on. .

  In the case where the partition wall formation step is performed after the pixel electrode formation step and the partition wall 12 is formed on the side of the other substrate 16 where the pixel electrode 161 is formed, the partition wall 12 side to the other substrate 16 side. The reference axis 125 of the partition wall 12 may be formed so as to be rotated 5 ° to 25 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed in the direction toward the side. Specifically, the virtual reference axis rotated by 5 ° to 25 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed in the direction from the side where the partition wall 12 is formed toward the other substrate 16 side. 12 reference axes 125, and a pattern in which the unit patterns are regularly arranged so that the reference axis 125 and one of the lines connecting opposing branch points in each hexagonal unit pattern are parallel A partition 12 may be formed on the side of the other substrate 16 on which the pixel electrode 161 is formed based on the reference pattern. In this way, when viewed in the direction from the partition 12 side toward the other substrate 16, one of the lines connecting the opposing branch points in each unit pattern of the reference pattern of the partition 12 is the edge of the pixel electrode 161. The partition wall 12 is formed so as to have a relationship of being rotated by 5 ° to 25 ° with respect to the line 165 extending in parallel with any of the above.

  As described above, according to the present embodiment, the plurality of pixel electrodes 161 are arranged in a periodic pattern, whereas the partition wall 12 is directed from one substrate 11 side to the other substrate 16 side. When viewed in the direction, at least a part of the branch points of the partition wall 12 exists within a predetermined distance starting from the branch point of the reference pattern when the hexagonal unit patterns are regularly arranged as a reference pattern. In addition, it is formed such that it does not overlap with the branch point of the reference pattern. Thereby, the expression of moire can be suppressed.

  Further, according to the knowledge obtained by the present inventors, in the present embodiment, any one of the lines connecting the opposing branch points in each unit pattern of the reference pattern of the partition wall 12 and any one of the edges of the pixel electrode 161. When the range of the angle of rotation between the line extending in parallel with the line is 5 ° to 25 °, a region where the overlap of the pattern of the partition wall 12 and the pixel electrode 161 is sparse and a region where the pattern is dense are formed finely, It is possible to suppress the appearance of a visual stripe pattern, that is, moire, due to a region where the overlapping pattern of the partition wall 12 and the pixel electrode 161 is sparse and a region where the pattern overlaps is not problematic. This angle range is defined by the partition 12 so that the occurrence of moire can be suppressed to a practically no problem when the pattern of the partition 12 is a pattern in which hexagonal unit patterns are regularly arranged. More than the range of rotation angles (10 ° to 20 °) between any one of the lines connecting the opposite corners of each cell and a line extending in parallel with one of the edges of each pixel electrode 161. wide. In other words, in this embodiment, the range of the angle of rotation between the reference axis 125 of the partition wall 12 and the reference axis 165 of the pixel electrode 161 that can suppress the occurrence of moire to a practically no problem level. Compared with the case of the first embodiment, the range can be wider.

  A line 165 in which one of the lines connecting one of the substrates 11 and the other substrate 16 connecting the opposing branch points in each unit pattern of the reference pattern of the partition wall 12 extends in parallel to one of the edges of the pixel electrode 161. The arrangement of the moiré can be more effectively suppressed by being arranged so as to have a relationship of being rotated by 5 ° to 25 ° with respect to the arrangement.

  In addition, since the reference pattern is a pattern in which regular hexagonal unit patterns are regularly arranged, the occurrence of moire is effectively suppressed.

  Next, practical examples actually performed will be described.

<Example of Reflective Display Device>
<Example 1-1>
As one substrate 11, an indium tin oxide (ITO) vapor deposition film (thickness 0.2 μm) is provided as a translucent electrode 111 on one surface of a 300 mm × 400 mm × 0.1 mm thick PET substrate (Toyobo A4100). A prepared substrate was prepared. The translucent electrode 111 is formed by a general film forming method such as sputtering, vacuum evaporation, or CVD, and in addition to indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), or the like. Can also be formed.

  Next, a negative photosensitive resin material (a dry film resist manufactured by DuPont MRC Dry Film Resist Co., Ltd.) is laminated on the one substrate 11 to a thickness of 20 μm and heated at 100 ° C. for 1 minute. Then, exposure is performed using an exposure mask (exposure amount: 500 mJ / cm 2), and thereafter development using a 1% KOH aqueous solution is performed for 30 seconds, followed by baking under the conditions of 200 ° C. and 60 minutes. The partition wall 12 was formed. The pattern of the partition walls 12 was a honeycomb pattern (pitch 300 μm) in which regular hexagonal unit patterns were regularly arranged. The partition wall 12 is arranged such that a line connecting opposing corner portions of the regular hexagonal unit pattern is rotated by 15 ° with respect to the longitudinal axis of one substrate 11 in a plan view of the one substrate 11. It was formed so as to be arranged in parallel to the virtual reference axis 125 in the relationship.

  A polyethylene terephthalate (PET) film 21 (manufactured by Teijin DuPont) having a thickness of 50 μm is used as the transfer film substrate 21, and a heat sealant 221 (Byron 630 manufactured by Toyobo Co., Ltd.) having a thickness of 20 μm is used with a die coater. Applied and dried. Thereby, a roll-shaped transfer sheet 20 having a 10 μm adhesive layer was produced. The softening temperature of the heat sealant 221 was about 110 ° C.

  Then, one substrate 11 was placed on the transfer sheet 20 with the surface on which the partition wall 12 was formed facing down, and was laminated at room temperature with a pressing force of about 1 kPa in this state. . Thereafter, the periphery of the heat sealant 221 was heated to a temperature exceeding its softening temperature, for example, about 130 ° C., and one substrate 11 was peeled from the transfer sheet 20 in that state. As a result, the heat sealant 221 was thermally transferred to the entire top surface of the partition wall 12. The height of the heat sealant 221 transferred to the top surface of the partition wall 12, that is, the height from the top surface of the partition wall 12 to the top of the heat sealant 221, that is, the thickness of the adhesive layer 22 is about 7 μm. Met.

Subsequently, an ink 13 having the following components is used as a display medium, dropped from the dispenser 31, and squeezed with a central squeegee 32 (Neurong squeegee 1: made of urethane resin), and then in each cell. Filled. Excess ink that protruded in the substrate width direction was scraped off by another squeegee 33a, 33b (Nelogue Squeegee 2: made of urethane resin), and further wiped off by a roll wiper 34.
<Ink component>
・ Electrophoretic particles (titanium dioxide): 60 parts by weight ・ Dispersion liquid: 40 parts by weight

  Subsequently, a silver paste (manufactured by Fujikura Kasei Co., Ltd.) was spot-coated by a dispenser 41 on a part of the outer periphery of the partition wall pattern (2 mm × 2 mm square region).

  Next, 600 × 800 square pixel electrodes 161 of 300 μm × 300 μm are formed on one surface of non-alkali glass (OA-10G manufactured by Nippon Electric Glass) having a size of 300 mm × 400 mm × 0.5 mm as the other substrate 16. A substrate provided with an amorphous TFT active matrix arranged in a matrix direction was prepared. The amorphous TFT active matrix is generally used in a liquid crystal display or the like, and the material of the pixel electrode 161 is an aluminum alloy. In the plurality of pixel electrodes 161, two opposing edge portions of each pixel electrode 161 are parallel to a virtual reference axis 165 parallel to the longitudinal axis of the other substrate 16 in a plan view of the other substrate 16. Formed as follows.

  Then, in the atmosphere, the other substrate 16 is placed on the adhesive layer 22 on the partition wall 12 of one substrate 11 so that the longitudinal axes of the one substrate 11 and the other substrate 16 coincide, that is, The reference axis 125 of the partition wall 12 is rotated by 15 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed from the substrate 11 side toward the other substrate 16 side. As a result, the one substrate 11 and the other substrate 16 connect opposite corners in each cell partitioned by the partition wall 12 when viewed from the one substrate 11 side toward the other substrate 16 side. Any of the lines is arranged so as to have a relationship of being rotated by 15 ° with respect to the line 165 extending in parallel with any of the edges of each pixel electrode 161. In this state, the partition 12 of one substrate 11 and the other substrate 16 are in close contact with each other while extruding excess ink exceeding the cell volume in the partition 12 while further applying a constant thermocompression pressure with the laminator 91. It was done.

  The temperature at the time of thermocompression bonding is a temperature near the softening point or melting point of the heat sealant 221 of the adhesive layer 22 and is preferably a temperature at which ink evaporation does not accelerate, preferably 80 ° C. to 150 ° C., preferably 80 ° C. to 90 ° C. It was 80 ° C. in this example. The thermocompression bonding pressure is preferably 0.01 MPa to 0.7 MPa, particularly preferably 0.1 MPa to 0.4 MPa, and 0.3 MPa in this example.

  Thereafter, the sheet is cut into a predetermined size by the cutting device 51, and a UV curable resin (LCB-610, manufactured by E-Heat Sea Co., Ltd.) is applied to the periphery of both substrates 11 and 16 using a dispenser (not shown). Then, it was cured by exposure to ultraviolet rays (exposure amount 700 mJ / cm 2) (peripheral sealing treatment). Thus, a display panel was produced.

  The display quality of the display panel obtained as described above was evaluated, but there was no unevenness due to the moire phenomenon.

<Example 1-2>
With respect to Example 1-1, the virtual reference axis 125 of the partition wall 12 is arranged so as to be rotated by 10 ° with respect to the longitudinal axis of the one substrate 11 in a plan view of the one substrate 11. The display panel was manufactured in the same process as specified. In the display panel, the reference axis 125 of the partition wall 12 is arranged by being rotated by 10 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed from the one substrate 11 side toward the other substrate 16 side. It was. That is, as viewed in the direction from the one substrate 11 side toward the other substrate 16 side, one of the lines connecting the opposing corners in each cell partitioned by the partition walls 12 is the edge of each pixel electrode 161. It was rotated by 10 ° with respect to a line 165 extending in parallel with any of the above.

  The display quality of the display panel obtained as described above was evaluated, but there was no unevenness due to the moire phenomenon.

<Example 1-3>
With respect to Example 1-1, the virtual reference axis 125 of the partition wall 12 is disposed so as to be rotated by 20 ° with respect to the longitudinal axis of the one substrate 11 in plan view of the one substrate 11. The display panel was manufactured in the same process as specified. In the display panel, the reference axis 125 of the partition wall 12 is rotated 20 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed from the one substrate 11 side toward the other substrate 16 side. It was. That is, as viewed in the direction from the one substrate 11 side toward the other substrate 16 side, one of the lines connecting the opposing corners in each cell partitioned by the partition walls 12 is the edge of each pixel electrode 161. It was rotated 20 ° with respect to a line 165 extending in parallel with any of the above.

  The display quality of the display panel obtained as described above was evaluated, but there was no unevenness due to the moire phenomenon.

<Comparative Example 1-1>
With respect to Example 1-1, the virtual reference axis 125 of the partition wall 12 is arranged so as to be rotated by 5 ° with respect to the longitudinal axis of the one substrate 11 in a plan view of the one substrate 11. The display panel was manufactured in the same process as specified. In the display panel, the reference axis 125 of the partition wall 12 is rotated by 5 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed from the one substrate 11 side toward the other substrate 16 side. It was. That is, as viewed in the direction from the one substrate 11 side toward the other substrate 16 side, one of the lines connecting the opposing corners in each cell partitioned by the partition walls 12 is the edge of each pixel electrode 161. It was rotated 5 ° with respect to a line 165 extending in parallel with any of the above.

  When the display quality of the display panel obtained as described above was evaluated, unevenness due to the moire phenomenon occurred.

<Comparative Example 1-2>
With respect to Example 1-1, the virtual reference axis 125 of the partition wall 12 is arranged so as to be rotated by 25 ° with respect to the longitudinal axis of the one substrate 11 in a plan view of the one substrate 11. The display panel was manufactured in the same process as specified. In the display panel, the reference axis 125 of the partition wall 12 is arranged by being rotated by 25 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed from the one substrate 11 side toward the other substrate 16 side. It was. That is, as viewed in the direction from the one substrate 11 side toward the other substrate 16 side, one of the lines connecting the opposing corners in each cell partitioned by the partition walls 12 is the edge of each pixel electrode 161. It was rotated by 25 ° with respect to a line 165 extending in parallel with any of the above.

  When the display quality of the display panel obtained as described above was evaluated, unevenness due to the moire phenomenon occurred.

<Example 2-1>
With respect to Example 1-1, the partition 12 was formed as follows, and the other processes were the same and a display panel was manufactured.

  That is, first, a virtual line arranged by being rotated by 15 ° with respect to the longitudinal axis of one substrate 11 in a plan view of one substrate 11 was defined as a virtual reference axis 125 of the partition wall 12. Next, a plurality of regular hexagonal unit patterns are arranged so that any of the lines connecting opposing corners in each regular hexagonal unit pattern is parallel to the virtual reference axis 125, and thus obtained. The pattern was used as a reference pattern for the partition wall 12. Then, when the partition wall 12 is viewed from the one substrate 11 side toward the other substrate 16 side, at least a part of the branch points of the partition wall 12 starts from the branch point of the reference pattern. It was formed so as to exist within a distance equal to one-fourth of the length of the extended side and not overlap with the branch point of the reference pattern.

  In the display panel, the reference axis 125 of the partition wall 12 is rotated by 15 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed in the direction from the one substrate 11 side toward the other substrate 16 side. It was. That is, the partition wall 12 and the pixel electrode 161 are either one of lines connecting corners facing each other in each cell partitioned by the partition wall 12 when viewed from the one substrate 11 side toward the other substrate 16 side. Are arranged relative to each other such that they are rotated by 15 ° with respect to a line 165 extending parallel to one of the edges of each pixel electrode 161.

  The display quality of the display panel obtained as described above was evaluated, but there was no unevenness due to the moire phenomenon.

<Example 2-2>
With respect to Example 2-1, the virtual reference axis 125 of the partition wall 12 is arranged so as to be rotated by 10 ° with respect to the longitudinal axis of the one substrate 11 in a plan view of the one substrate 11. The display panel was manufactured in the same process as specified. In the display panel, the reference axis 125 of the partition wall 12 is arranged by being rotated by 10 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed from the one substrate 11 side toward the other substrate 16 side. It was. That is, the partition wall 12 and the pixel electrode 161 are either one of lines connecting corners facing each other in each cell partitioned by the partition wall 12 when viewed from the one substrate 11 side toward the other substrate 16 side. Are arranged with respect to each other such that they are rotated by 10 ° with respect to a line 165 extending parallel to one of the edges of each pixel electrode 161.

  The display quality of the display panel obtained as described above was evaluated, but there was no unevenness due to the moire phenomenon.

<Example 2-3>
With respect to Example 2-1, the virtual reference axis 125 of the partition wall 12 is arranged so as to be rotated by 20 ° with respect to the longitudinal axis of the one substrate 11 in a plan view of the one substrate 11. The display panel was manufactured in the same process as specified. In the display panel, the reference axis 125 of the partition wall 12 is rotated 20 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed from the one substrate 11 side toward the other substrate 16 side. It was. That is, the partition wall 12 and the pixel electrode 161 are either one of lines connecting corners facing each other in each cell partitioned by the partition wall 12 when viewed from the one substrate 11 side toward the other substrate 16 side. Are arranged with respect to each other such that they are rotated by 20 ° with respect to a line 165 extending parallel to one of the edges of each pixel electrode 161.

  The display quality of the display panel obtained as described above was evaluated, but there was no unevenness due to the moire phenomenon.

<Example 2-4>
With respect to Example 2-1, the virtual reference axis 125 of the partition wall 12 is arranged to be rotated by 5 ° with respect to the longitudinal axis of the one substrate 11 in a plan view of the one substrate 11. The display panel was manufactured in the same process as specified. In the display panel, the reference axis 125 of the partition wall 12 is rotated by 5 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed from the one substrate 11 side toward the other substrate 16 side. It was. That is, the partition wall 12 and the pixel electrode 161 are either one of lines connecting corners facing each other in each cell partitioned by the partition wall 12 when viewed from the one substrate 11 side toward the other substrate 16 side. Are arranged with respect to each other such that they are rotated by 5 ° with respect to a line 165 extending parallel to one of the edges of each pixel electrode 161.

  The display quality of the display panel obtained as described above was evaluated, but there was no unevenness due to the moire phenomenon.

<Example 2-5>
With respect to Example 2-1, the virtual reference axis 125 of the partition wall 12 is arranged so as to be rotated by 25 ° with respect to the longitudinal axis of the one substrate 11 in a plan view of the one substrate 11. The display panel was manufactured in the same process as specified. In the display panel, the reference axis 125 of the partition wall 12 is arranged by being rotated by 25 ° with respect to the reference axis 165 of the pixel electrode 161 when viewed from the one substrate 11 side toward the other substrate 16 side. It was. That is, the partition wall 12 and the pixel electrode 161 are either one of lines connecting corners facing each other in each cell partitioned by the partition wall 12 when viewed from the one substrate 11 side toward the other substrate 16 side. Are arranged relative to each other such that they are rotated by 25 ° with respect to a line 165 extending parallel to one of the edges of each pixel electrode 161.

  The display quality of the display panel obtained as described above was evaluated, but there was no unevenness due to the moire phenomenon.

  The creation conditions and evaluation results of each example and each comparative example are summarized in FIG.

  As can be seen from the results shown in FIG. 15, the pattern of the pixel electrode 161 is a matrix pattern in which rectangular unit patterns are regularly arranged, and the pattern of the partition walls 12 is a regular hexagonal unit pattern. In the case of the arranged honeycomb pattern, any one of the lines connecting the opposing corners in each cell partitioned by the partition walls 12 is 10 ° to a line extending in parallel with any one of the edge portions of each pixel electrode 161. When it was rotated 20 °, the occurrence of moire was suppressed to an extent that there was no practical problem.

  Further, the pattern of the pixel electrode 161 is a matrix pattern in which rectangular unit patterns are regularly arranged, and the partition wall 12 is viewed from the one substrate 11 side toward the other substrate 16 side, When the honeycomb pattern in which at least some branch points of the partition walls 12 are regularly arranged regular hexagonal unit patterns is used as a reference pattern, the branch pattern 12 exists within a predetermined distance from the branch point of the reference pattern, and When formed so as not to overlap with the branch point of the reference pattern, the partition wall 12 and the pixel electrode 161 are either of the lines connecting the opposing branch points in each unit pattern of the reference pattern of the partition wall 12. Are arranged with respect to each other such that they are arranged rotated by 5 ° to 25 ° with respect to a line extending parallel to one of the edges of the pixel electrode 161. As a result, the occurrence of moiré was suppressed to a level where there was no practical problem.

  Thus, when the pattern of the partition wall 12 is a honeycomb pattern in which regular hexagonal unit patterns are regularly arranged, the partition wall 12 is viewed in a direction from one substrate 11 side to the other substrate 16 side. When the honeycomb pattern in which at least some branch points of the partition walls 12 are regularly arranged regular hexagonal unit patterns is used as the reference pattern, the branch pattern 12 exists within a predetermined distance from the branch point of the reference pattern, and Compared with the case where the branch point of the reference pattern does not overlap, the latter case can suppress the occurrence of moire to the extent that there is no practical problem. The range of the angle of rotation between the virtual reference axis 125 and the virtual reference axis 165 of the pixel electrode 161 is wide.

  Note that the partition wall 12 may be formed with a non-periodic pattern, that is, a pattern that does not cause a moire phenomenon with respect to the periodic pattern of the pixel electrode 161. As a specific example of the non-periodic pattern of the partition wall 12, for example, there is a pattern of the partition wall 12 in which a plurality of cells partitioned by the partition wall 12 have different shapes. The shape may be different for all the cells, or the shape may be different for only some of the cells. Moreover, about the method of a shape change, there may exist periodicity and it may not have periodicity.

<Production Method 3-1 of Reflective Display Device>
With reference to FIG. 16 thru | or FIG. 23, the formation method of the pattern of the partition 12 by this Embodiment is demonstrated. In the present embodiment, when the pattern of the partition 12 is viewed in the direction from one substrate 11 to the other substrate 16, at least some of the branch points of the partition 12 formed based on the pattern have the same shape. When the unit pattern is regularly arranged as a reference pattern, the unit pattern is formed within a predetermined distance from the branch point of the reference pattern as a starting point, and does not overlap with the branch point of the reference pattern. The

  The “unit pattern” is an individual pattern surrounding individual areas divided by the entire pattern. The “reference pattern” is a pattern used as a reference (basic) when forming the final pattern, or the position of the branch point is a branch of the partition pattern of the reflective display device according to the present invention. This is a pattern to be compared with the position of a point.

  In the present embodiment, as shown in FIG. 16A, the unit pattern is a regular hexagonal pattern, and the reference pattern is a honeycomb-shaped pattern in which regular hexagonal unit patterns are regularly arranged. .

  Other shapes can be employed as the shape of the unit pattern and the reference pattern. For example, as shown in FIG. 16B, the unit pattern may be a square pattern. In this case, the reference pattern is a square lattice pattern in which square patterns are regularly arranged. It's okay. The unit pattern may be a hexagonal pattern other than a regular hexagon, a rectangular pattern other than a square, or another polygonal pattern.

  However, it is preferable to adopt a unit pattern and a reference pattern in which the number of partition walls 12 extending from each branch point of the partition walls 12 formed based on the unit pattern and the reference pattern is 3 or 4. This is because as the number of partition walls 12 extending from one branch point increases, the adhesive 221 tends to be thickened on the top surface of the partition wall 12 at the branch point, which will be described later. This is because the adhesive material 221 spreads over the other substrate 16 so as to greatly exceed the width of the partition wall 12 in the counter substrate disposing step described later, thereby reducing the cell aperture ratio.

  For example, in the pattern similar to the honeycomb pattern, the number of the partition walls 12 extending from each branch point of the partition wall 12 is 3, and in the pattern similar to the lattice pattern, the partition wall 12 extending from each branch point of the partition wall 12. Is four. However, a pattern in which both are mixed may be employed. In this case, the number of the partition walls 12 extending from each branch point of the partition wall 12 is different for each branch point.

  In the present embodiment, the pitch of the reference pattern is 300 μm. Here, “pitch” means a distance required to move adjacent unit patterns to overlap each other.

  In the present embodiment, the pattern of the partition walls 12 is temporarily formed so as to match the regular hexagonal honeycomb-shaped reference pattern described above. Next, at least a part of branch points of the temporarily formed partition wall 12 pattern (hereinafter referred to as “temporarily formed pattern”) is displaced within a predetermined distance from the branch point as a starting point. Form a pattern. In the present embodiment, all the branch points of the temporarily formed pattern are randomly displaced within a predetermined distance from the branch point.

  For example, as shown in FIG. 17, the branch point K of the temporary formation pattern shown in FIG. 16A is a circle having a center K and a radius R1 when the predetermined distance is R1, and the outer edge is A1. It is displaced within the area enclosed by the circle shown.

  As shown in FIG. 17, the range in which the branch point K can be displaced is larger as the predetermined distance is larger. In the present embodiment, the branch point K is randomly displaced within a predetermined distance range starting from the branch point K. Therefore, the greater the predetermined distance, the greater the degree of random displacement of the branch point K. Therefore, hereinafter, the predetermined distance is used as an index representing the degree of random displacement of the branch point K, that is, the degree of randomness.

  With reference to FIG. 18, the difference in the degree of deformation of the temporary formation pattern due to the difference in the predetermined distance will be described.

  FIG. 18A is a diagram showing a final partition pattern formed by randomly displacing the branch point of the temporary formation pattern within the predetermined distance R1 shown in FIG. FIG. 18 is a diagram showing a pattern of a final partition formed by randomly displacing a branch point of the temporary formation pattern within a range of randomness R2 larger than randomness R1 shown in FIG. FIG. 18C shows a final partition pattern formed by randomly displacing a branch point of the temporary formation pattern within a range of randomness R3 larger than randomness R2 shown in FIG. FIG. 18D is a final partition pattern formed by randomly displacing the branch point of the temporary formation pattern within the range of the randomness R4 larger than the randomness R3 shown in FIG. FIG.

  As can be seen from FIGS. 18A to 18D, the larger the degree of randomness, the more the difference between the final partition pattern obtained and the periodic reference pattern shown in FIG. Become.

  Here, the minimum displacement range of the branch point K for effectively suppressing the occurrence of the moire phenomenon will be described with reference to FIGS. 19 and 20. FIG. 19 is a diagram for explaining the mechanism of the occurrence of the moire phenomenon. According to the knowledge of the present inventors, the moire phenomenon is caused on the one substrate 11 when viewed in the direction from the one substrate 11 side to the other substrate 16 because the partition walls 12 are formed in a periodic pattern. The periodic pattern of the partition wall 12 that is visually recognized, or the high transmittance portion of the periodic pattern that the partition wall 12 forms on one substrate 11 when the partition wall 12 is formed of a material having high light transmittance. , And the pixel electrode 161 is formed in a periodic pattern on the other substrate 16, so that the other substrate 16 is viewed from the one substrate 11 side toward the other substrate 16. This is caused by the presence of the high reflectance portion of the periodic pattern formed by the pixel electrode 161 on the top. That is, the periodic pattern of the high transmissivity portion of one substrate 11 and the periodic pattern of the high reflectivity portion of the other substrate 16 overlap with each other with different periods and rotation deviations, so that one substrate As seen from the 11th side, periodic shading occurs, which is considered to be the cause of the occurrence of the moire phenomenon. Therefore, in order to effectively suppress the occurrence of the moire phenomenon, it is necessary that the periodicity of the pattern of the partition walls 12 be broken so that the occurrence of such periodic shading can be suppressed.

  FIG. 20 is a diagram for explaining an average minimum displacement range of the partition wall 12 for effectively suppressing the occurrence of the moire phenomenon.

  First, in order to consider the average minimum displacement range of the partition wall 12 that suppresses the occurrence of the moire phenomenon, the partition wall 12 overlaps the region between the adjacent pixel electrodes 161a and 161b (inter-pixel electrode region 165) (see FIG. The average minimum displacement amount of the partition wall 12 necessary for the displacement from the state (see FIG. 20 (a)) to the state where the gap does not overlap (see FIG. 20 (b)) will be considered. Specifically, the partition wall center line lw that equally divides the line width of the partition wall 12 coincides with the inter-electrode center line ls that equally divides the width of the inter-pixel electrode region 165 between the adjacent pixel electrodes 161a and 161b. From such a position (see FIG. 20A), the edge of the partition wall 12 on the one pixel electrode 161b side coincides with the edge of the other pixel electrode 161a on the inter-pixel electrode region 165 side (FIG. 20). Consider the amount of displacement of the partition wall 12 that can be displaced to (b).

  Assuming that the line width of the partition wall 12 is W and the width of the inter-pixel electrode region 165 (distance between the opposing edges of the pixel electrodes 161a and 161b adjacent to each other) is S, the average minimum displacement distance of the partition wall 12 Is (W / 2) + (S / 2).

  If the pattern of the final partition wall 12 is formed such that the partition wall 12 is displaced by a displacement amount (W / 2) + (S / 2) with respect to the partition wall formed by the temporary formation pattern, the moire phenomenon is caused. Expression can be effectively suppressed. Therefore, at least the side extending from the branch point K as the starting point is displaced by the displacement amount (W / 2) + (S / 2) due to the displacement of the branch point K that has been displaced the largest among the branch points of the temporary formation pattern. As described above, the displacement range of the branch point K, that is, the randomness may be determined.

  Next, the maximum displacement range of the branch point K, that is, the degree of randomness, for effectively suppressing the occurrence of roughness unevenness will be described with reference to FIGS.

  First, with reference to FIG. 21, the mechanism of occurrence of rough unevenness will be described. The rough unevenness is caused by the fact that the concentration of the electrically responsive material of the display medium 13 varies greatly from cell to cell. If the variation in the particle size of the electrically responsive material contained in the display medium 13 is large, the concentration of the electrically responsive material in the display medium 13 varies greatly depending on the cell depending on the method of encapsulating the display medium 13 in the cell. May occur.

  In the present embodiment, in order to enclose the display medium 13 in the cell so as not to generate bubbles in the cell, in the display medium arrangement process described later, the display medium 13 having an amount exceeding the volume of the cell As shown in FIG. 21, the substrate 11 is placed on the substrate 11 and, as shown in FIG. 21, from the one edge of the substrates 11 and 16 toward the other edge facing the edge (the cell of FIG. 21). The other substrate 16 is laminated and bonded onto the top surface of the partition wall 12 of the one substrate 11 while expelling the excess display medium 13 from the cell (in the direction from A to the cell B). At this time, the surplus display medium 13 of the cell A passes over the partition wall 12 between the cell A and the cell B and flows in the direction of the cell B, but the distance between the top surface of the partition wall 12 and the other substrate 16 is somewhat. In the following, the electrically responsive material having a large particle size cannot pass between the top surface of the partition wall 12 and the other substrate 16, and the electrical response of the display medium 13 flowing from the cell A to the cell B. The concentration of the conductive material is lower than the average concentration of the electrically responsive material. Thereby, the density | concentration of the electroresponsive material of the display medium 13 in the cell A changes.

  The change in concentration of the electrically responsive material in the display medium 13 in the cell A is larger as the volume of the cell A, and hence the cell area, is smaller. In addition, the greater the difference in the concentration of the electrically responsive material of the display medium 13 between cells, the greater the difference in reflectance, color change rate, etc. between cells.

  As described above, in a display panel having a large variation in cell area, as shown in FIG. 22, the variation in shading of each cell may increase, resulting in unevenness in roughness.

In the present specification and claims, the size of the variation in cell area is represented by a cell area distribution ratio represented by the following equation with reference to FIG.
Cell area distribution ratio (%) = {(S2-S1) / Sa} × 100
Here, Sa is the mode value of the cell area, S1 is smaller than the cell area Sa, and when the number of cells having the cell area Sa is N, the number of cells having the cell area S1 is N / S2 is a cell area that is larger than the cell area Sa and the number of cells having the cell area S2 is N / 2.

  In the present embodiment, the cell area distribution rate depends on the displacement range of the branch point K of the temporary formation pattern, that is, the randomness. As can be seen from FIG. 18, for example, when the randomness is R1 and the randomness is R4, the cell area variation is larger when the randomness is R4. Accordingly, the cell area distribution rate can be controlled by controlling the randomness.

  Here, according to the knowledge obtained by the present inventors, when the cell area distribution rate is less than 38.4%, occurrence of rough unevenness is sufficiently suppressed.

After the final barrier rib pattern is formed, the contour lines of the barrier ribs 12 are determined with the lines constituting the final barrier rib 12 pattern as the barrier rib center line lw that equally divides the line width of the barrier ribs 12. That is, FIG. As shown in 24, the final barrier rib pattern of the branch point K 'and K1' a line parallel to the partition centerline lw ₁ connecting to one side of the partition wall central line lw ₁ and W / 2 ( A line lw ₁ a separated by a distance half the line width of the partition wall 12 is determined as the contour line on the one side of the partition wall 12. Similarly, the final barrier rib pattern lines away from the partition wall center line lw ₂ a line parallel to the partition wall central line lw ₂ on one side of the just W / 2 connecting the branch point K 'and K2' of lw ₂ a is determined as the one outline of the partition wall 12. Then, an intersection K′a between the line lw ₁ a and the line lw ₂ a is determined as the vertex of the cell on the one side. In this way, the shape of the partition wall 12 defining a plurality of cells having different shapes from each other when viewed from the one substrate 11 side toward the other substrate 16 side is determined. 25 and 26 are plan views showing the partition 12 actually formed by the partition formation step of the present embodiment.

  The cell aperture ratio is preferably 70% or more, and particularly preferably 90% or more. The higher the aperture ratio, the wider the displayable area, so that high contrast can be obtained. In the present embodiment, the aperture ratio is preferably in the range of 80% to 98% from the viewpoint of contrast and the strength of the partition 12.

  According to the present embodiment, at least a part of the partition wall 12 is formed in a non-periodic pattern with respect to the plurality of pixel electrodes 161 arranged in a periodic pattern. That is, the occurrence of the moire phenomenon can be suppressed regardless of the alignment accuracy between the two.

  Further, the partition wall 12 and the translucent electrode 11 or the other element on one substrate 11 or the one substrate 11 are in contact with each other, and the partition wall 12 and the pixel electrode 161 or another element on the other substrate 16 are in contact with each other. Or when the other board | substrate 16 is mutually contact | abutting, the suppression effect of the expression of a moire phenomenon is remarkable. In this case, since the electrically responsive material cannot move on the contact surface of the partition wall 12 with the substrates 11, 16, etc., the visibility of the pattern of the partition wall 12 is not reduced. The occurrence of the phenomenon sometimes becomes a problem in practice. However, in the reflective display device according to the present embodiment, although the electrically responsive material cannot move on the contact surface with the substrates 11 and 16 of the partition wall 12, at least a part of the partition wall 12 is included. Since the non-periodic pattern, that is, the pattern that suppresses the occurrence of the moire phenomenon with respect to the periodic pattern of the pixel electrode 161 is formed, the occurrence of the moire phenomenon is remarkably suppressed.

  Further, the aperture ratio of the plurality of cells partitioned by the partition wall 12 is 80% to 98% in the region corresponding to each pixel electrode 161 when viewed from the one substrate 11 side toward the other substrate 16 side. Therefore, the display area can be widened to obtain high contrast, and a sufficiently high partition 12 strength can be ensured.

  The number of partition walls 12 extending from each branch point of the partition walls 12 is three. Accordingly, the number of the partition walls 12 extending from one branch point is too large, and the possibility that the adhesive 22 is thickly deposited on the top surface of the partition wall at the branch point in the adhesive layer forming step is reduced and thickened. The risk that the adhesive 221 spreads over the other substrate 16 so as to greatly exceed the width of the partition wall 12 in the counter substrate placement step and the cell aperture ratio is reduced is also reduced. In addition, in the pattern similar to the honeycomb pattern like the pattern of the partition wall 12 of the present embodiment, the number of partition walls extending from each branch point of the partition wall is 3, but in the pattern similar to the lattice pattern, each partition wall The number of partition walls extending from the branch point is four. Also in this case, the risk that the number of the partition walls 12 extending from one branch point is too large and the adhesive 22 is thickly deposited on the partition top surface of the branch point in the adhesive layer forming step is reduced. Therefore, the possibility that the thick adhesive material 221 reduces the aperture ratio of the cell is also reduced. However, as the pattern of the partition wall 12, a pattern in which a pattern similar to the honeycomb pattern and a pattern similar to the lattice pattern are mixed may be employed. In that case, the pattern extends from each branch point of the partition wall. The number of partition walls differs for each branch point.

  Further, when viewed in the direction from one substrate 11 to the other substrate 16, at least a part of the branch points of the partition wall 12 is a reference pattern when unit patterns having the same shape are regularly arranged as a reference pattern. It exists within the range of a predetermined distance starting from this branch point and does not overlap with the branch point of the reference pattern. Such a pattern of the barrier ribs 12 is an aperiodic pattern at least in a region near the branch point, but it is easy to adjust the aperture ratios of a plurality of cells partitioned by the barrier ribs as desired. is there.

<Production Method 3-2 of Reflective Display Device>
FIG. 27 illustrates a method of forming the pattern of the barrier ribs 12 as viewed from the one substrate 11 toward the other substrate 16 in the manufacturing method of the reflective display device according to the third to second embodiments of the present invention. FIG.

  The manufacturing method of the reflective display device in the present embodiment is a direction from one substrate 11 toward the other substrate 16 in the partition formation step, compared to the manufacturing method of the reflective display device according to the 3-1 embodiment. The method for forming the pattern of the partition walls 12 is different, and the other steps are substantially the same.

  With reference to FIG. 27, a method of forming a pattern of the partition 12 viewed in the direction from one substrate 11 to the other substrate 16 in the partition formation step of the present embodiment will be described.

  First, a reference pattern in which unit patterns having the same shape as shown in FIG. 16 are regularly arranged is prepared. In the present embodiment, the reference pattern is a regular hexagonal honeycomb pattern shown in FIG. The pitch of the reference pattern is 300 μm.

  Next, a lattice pattern having a pitch corresponding to the reference pattern, that is, a pitch of 300 μm is prepared. In the present embodiment, the lattice pattern is a square lattice pattern. Next, each lattice point of the square lattice pattern is associated with each branch point K, K1, K2,. The grid points of the square grid pattern are moved by enlarging or reducing each row or column of the square grid pattern in the direction of the row or column, and the grid points corresponding to the movement of the grid points The branch points K, K1, K2,..., K6 associated with are also moved. FIG. 27 is a diagram showing the positions after movement of the branch points K, K1, K2,..., K6 of the reference pattern moved in correspondence with the movement of each lattice point of the square lattice pattern.

  In the present embodiment, the square lattice pattern is randomly expanded or reduced in the x-axis direction (row direction) in FIG. 27 within a predetermined distance. Similarly, enlargement or reduction of the square lattice pattern in the y-axis direction (column direction) in FIG. 27 is also randomly performed within a predetermined distance. In the present embodiment, the maximum displacement of each lattice line due to enlargement or reduction in the row direction and column direction of the square lattice pattern is set to 50 μm.

  Next, the branch points K, K1, K2,..., K6 of the reference pattern are moved in correspondence with the movement of the lattice points of the square lattice pattern expanded or reduced in the row direction or the column direction in this way. The positions after the movement of the respective branch points K, K1, K2,..., K6 are determined as the positions of the branch points K ′, K1 ′, K2 ′,.

For example, as shown in FIG. 27, the branch point K6 shown in FIG. 16 (a) is associated with the grid point _{p 43} and _{p 53,} the position vector after displacement of the grid points _{p 43} and _{p 53} each _(x 3, y ₄ ) and (x ₃ , y ₅ ), the branch point K6 has the position vector of the point after displacement of the branch point K6, that is, the position vector of the point K6 ′ in FIG. 27 is (x ₃ , y _a ). Where _ya is
It is a value satisfying (y ₅ −y _a ) :( y _a −y ₄ ) = √3: 1.

Further, the branch point K2 in FIG. 16A is associated with the lattice points p ₅₂ and p ₅₃ , and the position vectors after displacement of the lattice point p ₅₂ are (x ₂ , y ₅ ) and (x ₃ , y ₅ ), respectively. , The branch point K2 is such that the position vector of the point after displacement of the branch point K2, that is, the position vector of the point K2 ′ in FIG. 27 is ((x ₂ + x ₃ ) / 2, y _b ). Is displaced. Where y _b is
(Y ₅ −y _b ) :( y _b −y ₄ ) = 1: 2 is satisfied.

  Next, the positions determined as the positions of the branch points K ′, K1 ′, K2 ′,..., K6 ′ of the partition wall 12 are the branch points K ′, K1 ′, K2 ′,. , A branch pattern portion 121 having a plurality of branch extension portions 122 extending from the respective branch points K ′, K1 ′, K2 ′,..., K6 ′ of the partition wall 12 is positioned. The connecting portion 124 is positioned between the end portions 123 of the branch extending portion 122.

  The pattern of the partition wall 12 formed in this way is less likely to cause a moire phenomenon with respect to the periodic pattern of the pixel electrode 161.

<Method for Manufacturing Reflective Display Device 3-3>
The manufacturing method of the reflective display device in the present embodiment is different from the manufacturing method of the reflective display device according to the 3-1 and 3-2 embodiments from the one substrate 11 to the other in the partition forming step. The only difference is the method of determining the shape of the partition wall 12 as viewed in the direction toward the substrate 16, and the other steps are substantially the same.

  A method for determining the shape of the partition 12 viewed in the direction from one substrate 11 to the other substrate 16 in the partition formation step of the present embodiment will be described.

  First, a reference pattern in which unit patterns having the same shape as shown in FIG. 16 are regularly arranged is prepared. In the present embodiment, the reference pattern is a regular hexagonal honeycomb pattern shown in FIG. The pitch of the reference pattern is 300 μm.

  Next, a lattice pattern having a pitch corresponding to the reference pattern, that is, a pitch of 300 μm is prepared. In the present embodiment, the lattice pattern is a square lattice pattern. Next, each lattice point of the square lattice pattern is associated with each branch point of the reference pattern. The grid points of the square grid pattern are moved by enlarging or reducing each row or column of the square grid pattern in the direction of the row or column, and the grid points corresponding to the movement of the grid points Each branch point associated with is also moved to form a second reference pattern as shown in FIG.

Next, the branch points K ′, K1 ′, K2 ′,..., K6 ′ of the partition wall 12 are positioned within a predetermined distance range _Rmax starting from the branch point of the second reference pattern.

  Next, the branch points K ′, K1 ′, K2 ′,..., K6 ′ of the partition wall 12 thus positioned are extended from the branch points K ′, K1 ′, K2 ′,. The branch pattern part 121 having a plurality of branch extension parts 122 to be output is positioned, and the connection part 124 is positioned between the end parts 123 of the branch extension part 122 of the branch pattern part 121.

The pattern of the partition wall 12 formed in this way is less likely to cause a moire phenomenon with respect to the periodic pattern of the pixel electrode 161.
Next, practical examples actually performed will be described.

<Example of Reflective Display Device>
<Example 3-1>
As one substrate 11, an indium tin oxide (ITO) vapor deposition film (thickness 0.2 μm) is provided as a translucent electrode 111 on one surface of a 300 mm × 400 mm × 0.1 mm thick PET substrate (Toyobo A4100). A prepared substrate was prepared. The translucent electrode 111 is formed by a general film forming method such as sputtering, vacuum evaporation, or CVD, and in addition to indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), or the like. Can also be formed.

  Next, a negative photosensitive resin material (a dry film resist manufactured by DuPont MRC Dry Film Resist Co., Ltd.) is laminated on the one substrate 11 to a thickness of 20 μm and heated at 100 ° C. for 1 minute. Then, exposure is performed using an exposure mask (exposure amount: 500 mJ / cm 2), and thereafter development using a 1% KOH aqueous solution is performed for 30 seconds, followed by baking under the conditions of 200 ° C. and 60 minutes. The partition wall 12 was formed. The pattern of the partition walls 12 is like the pattern shown in FIG. 18B by randomly displacing all branch points of the temporarily formed pattern that is temporarily formed using a regular hexagonal honeycomb pattern (pitch 300 μm) as a reference pattern. Been formed. The width of the top surface of the partition wall 12 was 20 μm. The average cell diameter of the cells partitioned by the partition walls 12 was 300 μm, and the cell area distribution ratio was 26.8%. Here, the diameter of a cell is defined as the distance between cell centers between adjacent cells. In addition, if the cell is a hexagon, the position of the cell center of each cell can be obtained by averaging the coordinates of the six vertices of the cell.

  A polyethylene terephthalate (PET) film 21 (manufactured by Teijin DuPont) having a thickness of 50 μm is used as the transfer film substrate 21, and a heat sealant 221 (Byron 630 manufactured by Toyobo Co., Ltd.) having a thickness of 20 μm is used with a die coater. Applied and dried. Thereby, a roll-shaped transfer sheet 20 having a 10 μm adhesive layer was produced. The softening temperature of the heat sealant 221 was about 110 ° C.

  Then, one substrate 11 was placed on the transfer sheet 20 with the surface on which the partition wall 12 was formed facing down, and was laminated at room temperature with a pressing force of about 1 kPa in this state. . Thereafter, the periphery of the heat sealant 221 was heated to a temperature exceeding its softening temperature, for example, about 130 ° C., and one substrate 11 was peeled from the transfer film 20 in that state. As a result, the heat sealant 221 was thermally transferred to the entire top surface of the partition wall 12. The height from the top surface of the partition 12 to the top of the heat sealant 221 was about 7 μm.

Subsequently, an ink 13 having the following components is used as a display medium, dropped from the dispenser 31, and squeezed with a central squeegee 32 (Neurong squeegee 1: made of urethane resin), and then in each cell. Filled. Excess ink that protruded in the substrate width direction was scraped off by another squeegee 33a, 33b (Nelogue Squeegee 2: made of urethane resin), and further wiped off by a roll wiper 34.
<Ink component>
・ Electrophoretic particles (titanium dioxide): 60 parts by weight ・ Dispersion liquid: 40 parts by weight

  Subsequently, a silver paste (manufactured by Fujikura Kasei Co., Ltd.) was spot-coated by a dispenser 41 on a part of the outer periphery of the partition wall pattern (2 mm × 2 mm square region).

  Next, 600 × 800 square electrodes of 200 μm × 200 μm are formed on one surface of non-alkali glass (OA-10G manufactured by Nippon Electric Glass) as the other substrate 16 in a matrix of 300 mm × 400 mm × thickness 0.5 mm. A substrate provided with an amorphous TFT active matrix arranged in a direction was prepared. The amorphous TFT active matrix is generally used in a liquid crystal display or the like, and the material of the square electrode is an aluminum alloy.

  Then, in the atmosphere, the other substrate 16 is overlaid on the adhesive layer 22 on the partition wall 12 of one substrate 11, and a certain thermocompression pressure is further applied by the laminator 91, while the cells in the partition wall 12 are placed. The partition 12 of one substrate 11 and the other substrate 16 were brought into close contact with each other while extruding excess ink exceeding the volume.

  The temperature at the time of thermocompression bonding is a temperature in the vicinity of the softening point or melting point of the heat sealant 221, and is preferably a temperature at which the evaporation of ink is not accelerated, and is 80 ° C to 150 ° C, preferably 80 ° C to 90 ° C. In the examples, the temperature was 80 ° C. The thermocompression bonding pressure is preferably 0.01 MPa to 0.7 MPa, particularly preferably 0.1 MPa to 0.4 MPa, and 0.3 MPa in this example.

Thereafter, the sheet is cut into a predetermined size by the cutting device 51, and a UV curable resin (LCB-610, manufactured by E-Heat Sea Co., Ltd.) is applied to the periphery of both substrates 11 and 16 using a dispenser (not shown). Then, it was cured by exposure to ultraviolet rays (exposure amount 700 mJ / cm ² ) (peripheral sealing treatment). Thus, a display panel was produced.

  The display quality of the display panel obtained as described above was evaluated, but there was no unevenness due to the moire phenomenon, the particle concentration between the cells was uniform, and there was no roughness unevenness.

<Comparative Example 3-1>
A display panel was fabricated in the same process as in Example 3-1, except that the pattern of the partition walls 12 was a honeycomb pattern (pitch 300 μm) in which regular hexagonal unit patterns were regularly arranged.

  When the display quality of the display panel obtained as described above was evaluated, unevenness due to the moire phenomenon occurred.

<Example 3-2>
With respect to Example 3-1, the pattern of the partition wall 12 was temporarily formed based on a square lattice-shaped reference pattern (pitch 300 μm) formed by regularly arranging square unit patterns, and the temporary formation was performed. A display panel was manufactured in the same process as shown in FIG. 28 by randomly displacing all branch points of the pattern.

  The display quality of the display panel obtained as described above was evaluated, but there was no unevenness due to the moire phenomenon.

<Comparative Example 3-2>
Compared to Example 3-2 above, the pattern of the partition walls 12 is a square lattice pattern (pitch 300 μm) formed by regularly arranging square unit patterns shown in FIG. A panel was produced.

  When the display quality of the display panel obtained as described above was evaluated, unevenness due to the moire phenomenon occurred.

<Comparative Example 3-3>
With respect to Example 3-1, the pattern of the partition wall 12 was changed to the Penrose pattern (side length 100 μm) shown in FIG.

  When the display quality of the display panel obtained as described above was evaluated, unevenness due to the moire phenomenon occurred. Further, in the vicinity of the branch point where the number of the partition walls 12 extending from the branch point of the partition wall 12 is 5 or more, the adhesive layer 22 formed on the partition wall 12 greatly exceeds the width of the partition wall 12 on the other substrate 16. It spreads, reducing the aperture ratio of the cell.

11 One substrate 111 Translucent electrode 12 Partition 125 Reference axis 13 of partition wall Ink (display medium)
16 Other substrate 161 Pixel electrode 165 Pixel electrode reference axis 22 Adhesive layer 221 Heat seal agent 31 Dispenser 32 Applicator 51 Cutting device 91 Laminator

Claims (1)

Desirable when a display medium containing at least one or more kinds of electrically responsive materials is sealed between two opposing substrates on which electrodes are formed, and a predetermined electric field is applied between the two substrates. A reflective display device that displays
One substrate has translucency,
Between the one substrate and the other substrate, a common translucent electrode covering at least a display region, a partition partitioning a plurality of cells, and a plurality of pixel electrodes arranged in a periodic pattern, Provided in that order as viewed from the one substrate side toward the other substrate side,
The pattern of the pixel electrode is a pattern in which rectangular unit patterns are regularly arranged.
When viewed from the side of the one substrate toward the side of the other substrate, at least some of the branch points of the partition walls are arranged when regular hexagonal unit patterns are regularly arranged as a reference pattern. It exists within a predetermined distance starting from the branch point of the reference pattern, and does not overlap with the branch point of the reference pattern,
The range of the predetermined distance is a range of distances equal to or less than half the length of the side extending from the branch point starting from each branch point of the reference pattern,
The partition wall and the pixel electrode are any one of lines connecting opposing branch points in each unit pattern of the reference pattern of the partition wall when viewed from the one substrate side toward the other substrate side. Is in a relationship of being rotated and arranged by 5 ° to 25 ° with respect to a line extending in parallel with one of the edge portions of the pixel electrode.