Optical modulator including fluid distribution protrusions

Abstract

Some embodiments relate to an optical modulator, the optical modulator comprising a first substrate, a second substrate arranged opposite to the first substrate, at least one electrode applied to at least the first substrate on a surface facing the second substrate, and an optical layer extending between the first substrate and the second substrate. The optical modulator further comprises a plurality of fluid distribution protrusions for controlling fluid flow within the optical layer, wherein the plurality of fluid distribution protrusions are distributed over a region of the surface of at least one of the first substrate and the second substrate, the region has a density of at least 10 fluid distribution protrusions per mm² and / or the combined area of ​​the fluid distribution protrusions is at least 0.1% of the surface of the first substrate.

Description

Background Technology

[0001] A known optical modulator is disclosed in WO2022023180, which is incorporated herein by reference. The known optical modulator comprises transparent or reflective substrates. A plurality of electrodes are applied to the substrates in a pattern across the substrates. A controller can obtain an electromagnetic field between the electrodes by applying an electric potential to the electrodes to provide electrophoretic movement of particles toward or away from the electrodes.

[0002] An optical modulator, a substrate for use in an optical modulator, a method for modulating light, and a method for manufacturing an optical modulator are described in the appended claims. Specific embodiments of the invention are described in the dependent claims.

[0003] In an embodiment, the optical modulator comprises a first substrate, a second substrate arranged opposite to the first substrate, at least one electrode applied to at least the first substrate on a surface facing the second substrate, and an optical layer extending between the first substrate and the second substrate, wherein the optical layer comprises a fluid containing particles.

[0004] The optical modulator may be configured to apply an electric potential to at least one electrode, and the application of the electric potential causes modulation of the electric field within the optical layer, and the modulation of the electric field provides electrophoretic and / or dielectrophoretic movement of particles within the optical layer, thereby causing modulation of light passing through the optical layer.

[0005] The optical modulator may further include a plurality of fluid distribution protrusions for controlling fluid flow within an optical layer, wherein the plurality of fluid distribution protrusions are distributed across a region of the surface of at least one of the first substrate and the second substrate, the region has a density of at least 10 fluid distribution protrusions per mm² and / or the combined area of ​​the fluid distribution protrusions is at least 0.1% of the surface of the first substrate. Brief explanation of the drawing

[0006] Additional details, aspects, and embodiments will be described by way of example with reference to the drawings. Elements in the drawings are illustrated for simplicity and clarity and are not necessarily drawn to scale. In the drawings, elements corresponding to elements already described may have the same reference numbers. In the drawings, FIG. 1a schematically illustrates an example of an embodiment of a building block, and FIG. 1b schematically illustrates an example of an embodiment of a substrate, and FIG. 1c schematically illustrates an example of an embodiment of a substrate, and FIG. 1d schematically illustrates an example of an embodiment of a substrate, and FIG. 1e schematically illustrates an example of an embodiment of a substrate, and FIG. 1f schematically illustrates an example of an embodiment of a substrate, and FIG. 1g schematically illustrates an example of an embodiment of an optical modulator, and FIGS. 2a to 2f schematically illustrate examples of embodiments of a substrate, FIG. 3a schematically illustrates an example of an embodiment of an optical modulator, and FIG. 3b schematically illustrates an example of an embodiment of an optical modulator, and FIG. 3c schematically illustrates an example of an embodiment of a vehicle, and FIGS. 4a to 4c schematically illustrate embodiments of an optical modulator, FIGS. 5a to 5d schematically illustrate examples of embodiments of a substrate for use in an embodiment of an optical modulator, and FIGS. 6a to 6c schematically illustrate side views of examples of embodiments of an optical modulator, and FIGS. 7a through 7e schematically illustrate side views of examples of embodiments of an optical modulator, and FIG. 7f schematically illustrates examples of embodiments of fluid distribution protrusions, and FIG. 8a schematically illustrates an example of an ink droplet falling onto a substrate without spacers, and FIG. 8b schematically illustrates an example of an ink droplet falling onto a substrate with spacers, and FIG. 8c illustrates the result of ink droplet spreading after being dropped onto a substrate without spacers, and FIG. 8d illustrates the result of ink droplet spreading after being dropped onto a substrate with spacers, and FIG. 9a schematically illustrates an example of an embodiment of an optical modulator without spacers, and FIG. 9b schematically illustrates an example of an embodiment of an optical modulator having spacers, and FIGS. 10a and FIGS. 10b schematically illustrate examples of embodiments of a substrate, and FIG. 11 schematically illustrates an example of a method for modulating light according to an embodiment, and FIG. 12 schematically illustrates an example of a method for manufacturing an optical modulator according to an embodiment. List of reference symbols The following list of references and abbreviations corresponds to the drawings and is provided to facilitate the interpretation of the drawings and should not be interpreted as limiting the claims. 10 Optical Modulator 11 First substrate 12 Second substrate 13, 13a, 13b electrodes 14, 14a, 14b electrodes 15 Fluids 16 controllers 30 particles 20 cars 21 Optical modulator 40 optical modulators 41 First substrate 42 Second substrate 43 Third substrate 46 controllers 100-102 board 111-114 main line 121-124 main line 131-134 Interdigitated electrodes 140 building blocks Building Blocks 141-144 110, 120 drive bus 110', 120' drive bus 119, 129 connecting zone Directions 191, 192 203-204 board Building Blocks 211-222 Building Blocks 251-262 18, 18a-18k. Fluid distribution protrusions 18' spacers Surface regions of substrates 19, 19a, and 19b 45 days 71 Street 72 Street 72' board gap width 73, 73' height of the protrusion 74, 74' diameter of the protrusion 81 ink droplets Specific details for implementing the invention

[0007] Although the subject matter of the claims disclosed herein may be embodied in various different forms, one or more specific embodiments are illustrated in the drawings and described in detail herein; provided that the disclosure is to be understood as an example of the principles of the subject matter of the claims disclosed herein and is not intended to be limited to the specific embodiments illustrated and described.

[0008] In the following, for the sake of understanding, the elements of the embodiments are described as being in operation. However, it will be apparent that the individual elements are arranged to perform the functions described as being performed by them.

[0009] Additionally, the subject matter of the claims disclosed herein is not limited to embodiments but includes all other combinations of features described herein or in other dependent claims.

[0010] In an embodiment, the optical modulator is provided with fluid distribution protrusions within the optical modulator. The fluid distribution protrusions within the optical modulator are advantageous because they improve the flow of a fluid, such as a liquid, in the optical layer. This is advantageous during both manufacturing and operational use, where the fluid is prevented from overflowing over the seal. In an embodiment, the optical modulator may have low-density fluid distribution protrusions; and the optical modulator may have high-density fluid distribution protrusions.

[0011] Substrates are disclosed for use, for example, in optical modulators, particularly in dynamic glazing. The substrate is transparent, and at least one electrode is applied to a surface of the substrate, and the electrode extends in a pattern across the surface of the first substrate. At least one of the first substrate and the second substrate is transparent. In glazing applications, both substrates are transparent. In other applications, such as displays, one of the two substrates may be opaque. The electrode may comprise a non-transparent material, in particular a reflective metal.

[0012] Dynamic glazing, also known as smart glazing, may include a system in which the transparency or optical properties of the glazing material are altered in response to an external electrical input. This system enables active control of light and heat transfer, thereby improving energy efficiency and user convenience in various architectural or automotive applications.

[0013] FIGS. 1a through 4c provide various examples of electrode systems on a first substrate and a second substrate and how they can be implemented or used in an optical modulator. In these examples, fluid distribution protrusions within the optical modulator may be provided.

[0014] Some of the known optical modulators in which fluid distribution protrusions within the optical modulator may be provided are based on the principle of electrophoresis. For example, a substrate may include a plurality of interdigitated electrodes applied to the substrate, such as two electrodes, each of which is arranged in a pattern across the substrate, and the plurality of interdigitated electrodes are arranged alternately with respect to one another on the substrate. Having a plurality of interdigitated electrodes enables local control of the electric field, which enables electrophoretic control of particles.

[0015] Electrophoretic optical modulators are described more extensively in this specification and are used as motivating examples. In an embodiment, the optical modulator comprises a first substrate and a second substrate. For example, at least one of the first substrate and the second substrate, having fluid distribution protrusions within the optical modulator, may be in accordance with the embodiment. For example, using a substrate according to the embodiment, the first substrate and the second substrate may be arranged so that their inner faces face each other. An optical layer is arranged between the first substrate and the second substrate. Electrodes are arranged to modulate an electric field in the optical layer. The optical layer comprises a fluid, such as a liquid, containing particles, and the particles are electrically charged or can be charged. The particles may be moved under the control of an electric field. For example, a controller may be configured to apply an electric potential to an electrode to obtain an electromagnetic field from the electrode that provides electrophoretic movement of particles toward or away from at least one of the electrodes, thereby causing modulation of the optical properties of the optical modulator. For example, optical properties may include transitions between high-transparency and low-transparency states, or vice versa. Note that transitions can also alter the thermal properties of the optical modulator.

[0016] In the following, many of the known optical modulators are reviewed, illustrating some of the options regarding the technology and electrodes. These known substrates may be advantageously modified by adding fluid distribution protrusions within the optical modulator according to the embodiment. These examples also show optical modulators having various numbers of electrodes on the substrate.

[0017] International patent applications WO2011012499 A1 (incorporated by reference herein) and WO2011131689 (incorporated by reference herein) disclose optical modulators in the form of electrophoretic display devices, such as e-Ink displays. A pixel of a display comprises an accumulation electrode and a field electrode, wherein the accumulation electrode is arranged in a storage region for accumulating charged particles away from the aperture region, and the field electrode occupies a field-electrode region that is at least part of the aperture region of the pixel, and the charged particles are movable between the accumulation electrode and the field electrode. In an embodiment, two electrodes are applied on a single substrate. Fluid distribution protrusions may be provided on the substrate having the accumulation electrode and / or the field electrode. Fluid distribution protrusions may be provided on the substrate having the electrodes, on the opposing electrode, or on both.

[0018] U.S. Patent 10921678 (incorporated herein by reference) titled “Electrophoretic Device” describes an electrophoretic device having only one patterned electrode on one of two substrates. For example, one substrate having the electrode according to U.S. 10921678 may be replaced with a substrate according to an embodiment having a single electrode. For example, an embodiment includes a first transparent substrate having a field electrode and a second substrate opposite to the first substrate having an accumulation electrode. The first substrate and the second substrate surround a pixel having fluid and particles. In use, an electromagnetic field applied to the field electrode and the accumulation electrode provides the movement of particles from the field electrode and the accumulation electrode and vice versa. Any of these cited electrophoretic or dielectrophoretic optical modulators may be adapted by including fluid distribution protrusions within the optical modulator.

[0019] U.S. Patent 8054535B2 (incorporated by reference herein) and U.S. Patent 8384659B2 (incorporated by reference herein) show alternative examples of electrophoretic optical modulators in which one of two substrates has two patterned electrodes.

[0020] Patterned electrodes are also used in dielectrophoretic optical modulators. For example, U.S. patent applications US2005185104A1 (incorporated herein by reference) and US20180239211A1 (incorporated herein by reference) disclose dielectrophoretic optical modulators comprising a substrate having patterned electrodes. Any of these cited electrophoretic or dielectrophoretic optical modulators may be adapted by including fluid distribution protrusions within the optical modulator.

[0021] The paper cited in "Reversible Metal Electrodeposition Devices: An Emerging Approach to Effective Light Modulation and Thermal Management" also shows a substrate with patterned electrodes applied. Fluid distribution protrusions within the optical modulator may be included herein.

[0022] An embodiment of the substrate may be used in an electrochromic device (ECD). An electrochromic device (ECD) controls optical properties, such as optical transmission, absorption, reflection, and / or emission, in a continuous but reversible manner upon the application of voltage (electrochromism). This property enables the electrochromic device to be used in applications such as smart glass, electrochromic mirrors, and electrochromic display devices. Fluid distribution protrusions within the optical modulator may be included herein.

[0023] Electrochromic devices are, for example, This is described in the paper "Silver grid electrodes for faster switching ITO-free electrochromic devices" by et al., which is incorporated herein by reference. This paper describes the preparation of an electrochromic device, in this case, an ITO-free device. Fluid distribution protrusions within an optical modulator may be incorporated herein by reference.

[0024] Electrochromic devices use electrically conductive electrodes applied on a substrate. The cited paper uses silver grids made using silver ink as electrically conductive electrodes. Electrochromic devices may include electrochromic materials. The cited paper uses poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). In an electrochromic device, at least one electrode, such as an electrically conductive electrode, is applied to a substrate. The electrodes are arranged in a pattern across the substrate. The cited paper discloses two different grid patterns, namely a regular honeycomb pattern and a regular ladder pattern design. Refer to Table 1 and Figure 3 of the cited paper. Fluid distribution protrusions within the optical modulator may be included herein.

[0025] The electrodes can be applied to a substrate by screen printing on a substrate, which in the case of the cited paper is polyethylene terephthalate (PET). The electrodes are typically electrically conductive materials, such as metals or metal oxides. In the cited paper, silver ink was used to screen print grids on PET using a RokuPrint RP 2.2 machine and an 180 wired mesh. The samples were allowed to dry in an oven at 130°C for 15 minutes. On top of these silver grids, one or two layers of PEDOT:PSS SV3 were subsequently screen printed. Fluid distribution protrusions within the optical modulator may be included herein.

[0026] Another example of an electrochromic device is disclosed in U.S. Patent 5161048 titled “Electrochromic window with metal grid counter electrode and acidic polyelectrolyte,” which is incorporated herein by reference. For example, the electrochromic device may include a transparent electrochromic film and an ion-conducting layer disposed between a pair of electrodes. A metal grid electrode is issued for said electrodes. FIG. 1 of said patent illustrates a metal grid according to the cited patent. To form a counter electrode, the metal grid is disposed near a second glass substrate.

[0027] For example, in an embodiment of an electrochromic device, the electrochromic device may include a transparent substrate, an electrically conductive electrode member, a transparent electrochromic film in contact with the electrically conductive electrode member, an ion-conducting polymer in contact with the electrochromic film, and a patterned conductive electrode in contact with the ion-conducting polymer. Fluid distribution protrusions within an optical modulator may be included herein.

[0028] The substrate according to the embodiment may be advantageously applied to a number of other technologies. For example, the optical modulator may be a dielectrophoretic optical modulator such as that described in US20050185104 A1, which is incorporated herein by reference. Fluid distribution protrusions within the optical modulator may be incorporated herein.

[0029] A substrate as in the embodiment may also be used in other electrowetting and OLED applications. In OLED and electrowetting, electrodes are required on only one of the substrates. A substrate having electrodes may be in accordance with the embodiment. The OLED layer may additionally or instead be coupled with an optical modulator as in the embodiment.

[0030] Other dynamic glass technologies can be used.

[0031] For example, an optical layer for a light modulator, such as a light modulator in dynamic glazing, may utilize Liquid Crystal Display (LCD) technology. For example, the optical layer may include liquid crystal molecules that can be aligned to control the amount of light passing through the display. When an electric current is applied to the liquid crystal molecules, the liquid crystal molecules change their alignment and alter the way light passes through the material. An optical layer having an LCD material may be placed between two glass or plastic layers and connected to an electrical circuit. By controlling the electric current applied to the LCD material, the amount of light passing through the glazing can be controlled. Fluid distribution protrusions within the light modulator may be included herein.

[0032] An optical layer for a light modulator, such as a light modulator in dynamic glazing, may utilize Suspended Particle Device (SPD) technology. The optical layer may contain suspended particles within a thin film or laminate. By applying an electric current to the SPD film, the particles align to change the amount of light passing through the material, thereby enabling dynamic control of the glazing. When the electric current is turned off, the suspended particles become randomized and allow more light to pass through, producing a sharp or transparent effect. When the electric current is turned on, the particles align and absorb more light, producing a darker or colored effect. Fluid distribution protrusions within the light modulator may be included herein.

[0033] In applications of optical modulators for glazing, both substrates are generally transparent. In other applications, such as televisions and e-readers, only one substrate may be transparent.

[0034] FIG. 1b schematically illustrates an example of an embodiment of a substrate. The substrate is particularly useful for use in optical modulators, such as optical modulators of the type described herein. An electrode system is applied in the form of a plurality of interdigitated electrodes across the substrate. Two interdigitated electrodes are illustrated in FIG. 1b. The substrate may include fluid distribution protrusions as in the embodiment.

[0035] The contact area can be arranged to enable electrical connection to at least one driving electrode applied on the substrate.

[0036] A representative exemplary use of the substrate is in an electrophoretic optical modulator. Generally, the electrophoretic optical modulator comprises at least two substrates, each substrate having at least two electrodes, but this is not strictly necessary; for example, the electrophoretic optical modulator may comprise a single substrate having two electrodes and a counter substrate having one electrode. In any case, preferably, at least one of the substrates in the optical modulator conforms to the embodiment.

[0037] An embodiment of the optical modulator includes a first substrate and a second substrate according to the embodiment. The first substrate and the second substrate are arranged such that their inner surfaces face each other. At least one electrode is applied to the inner surface of the first substrate. An optical layer is arranged between the first substrate and the second substrate. A controller is configured to apply an electric potential to at least one electrode, and the application of the electric potential causes modulation of the optical properties of the optical modulator. One or both of the first substrate and the second substrate are transparent and / or translucent.

[0038] There are many different types of optical modulators that use at least one electrode applied to a substrate. The optical layer and the controller may be arranged to modulate optical properties using effects that depend on the potential on the electrode, examples of which include dielectrophoretic and electrophoretic effects. For example, optical modulation may include modulation of particles arranged in the optical layer. The number of electrodes may range from one on a single substrate to multiple electrodes on both one or two substrates.

[0039] The optical layer arranged between the first substrate and the second substrate may contain particles, such as particles suspended in a fluid. The controller is configured to apply an electric potential to the electrodes, and the application of the electric potential causes the particles to move, thereby modulating the optical characteristics of the optical modulator.

[0040] In one embodiment, the particles include electrically charged or chargeable particles, and the controller is configured to obtain an electromagnetic field that provides electrophoretic movement of the particles by applying an electric potential to the electrodes. In one embodiment, the electromagnetic field is arranged between at least two electrodes arranged on the same substrate or on different substrates.

[0041] In an embodiment, the particles include dielectric particles, and the controller is configured to apply an electric potential to the electrodes to apply an electric field gradient to the particles, which enables the particles to move under the action of a dielectrophoretic force.

[0042] The controller may apply an electrical signal to one or more of the electrodes. Embodiments controlling the dielectrophoretic force may use a signal including a DC signal and / or an AC signal. Embodiments controlling the electrophoretic force may use a signal including a DC signal and / or an AC signal.

[0043] In FIG. 1b, two electrodes on the same plane are illustrated. The two electrodes are indicated in FIG. 1b by two different dashed line styles. For example, to facilitate finer control of voltage differences across the substrate, more than two electrodes may exist on the same plane of the substrate. The electrodes are applied to the same plane of the substrate. Applying the electrodes to the substrate can be performed by lithography, for example, using a mask that displays the electrode pattern. The electrodes can also be applied by embedding them in the substrate.

[0044] The electrodes are electrically connected and, for example, have the same electrical potential everywhere. The electrodes may include drive buses and main lines. At least the main lines are interdigitated with the main lines of additional electrodes. Generally, the electrodes extend substantially straight across the substrate, while the main lines are convolute.

[0045] In an embodiment, the two substrates of the optical modulator each have two electrodes arranged on their inner surfaces. However, as mentioned, it is not necessary to have multiple electrodes on both one or two substrates. For example, an embodiment of the optical modulator includes a first substrate and a second substrate. For example, the first substrate may include one electrode, and the second substrate may not include electrodes. For example, the first substrate may include two electrodes, and the second substrate may include one electrode. For example, the first substrate may include two electrodes, and the second substrate may include two electrodes. For example, the first substrate may include more than two electrodes, and the second substrate may include two or more electrodes.

[0046] However, optical modulators in which each substrate includes two electrodes are used as representative examples. Designs of substrates featuring two electrodes can be adapted to have a single electrode, for example, by connecting the two electrodes or by removing one of the electrodes. Adapting the substrate in this way can make it suitable for use in different technologies.

[0047] Each of the plurality of electrodes is arranged in a pattern across the substrate. The plurality of electrodes are arranged alternately with respect to one another on the substrate. Generally, the electrodes include a plurality of main lines, and each of the main lines extends across the substrate. The main lines of the electrodes are alternate, for example, interdigitated. For example, in FIG. 1b, the first electrode includes main lines (111-114), and the second electrode includes main lines (121-124). The electrodes are each driven by the driving buses of the electrodes. FIG. 1b illustrates two driving buses, namely driving bus (110) and driving bus (120). The electrodes also serve to connect the main lines to one another. For example, in FIG. 1b, the driving bus (110) drives and connects the main lines (111-114); and the driving bus (120) drives and connects the main lines (121-124). There may be more than four main lines shown in this example. The use of main lines is advantageous as it reduces the length of the electrodes, but it is not strictly necessary. While a design using only one main line per electrode is not impossible, having multiple main lines is advantageous.

[0048] The driving buses can be adapted to form contact areas that enable electrical connections to at least one driving electrode applied on the first substrate, such as connections from outside the optical modulator. This is not necessarily required, and additional contact areas may be provided on separate contact areas, such as on the driving buses (110 and 120), as in the embodiment.

[0049] A plurality of main lines of the first electrode and the second electrode are arranged alternately with respect to each other on the substrate.

[0050] In this example, there are no other connections between the main lines of the electrodes except through a common drive bus. In an embodiment, the electrode includes a mesh electrode, which allows additional electrical connections to be added between the electrode lines of the same electrode. This increases the reliability of the electrode. These additional connections generally cross the electrode lines of other electrodes, which can be resolved by partially placing the additional electrical connections on different levels relative to the intersecting electrode lines and the substrate. For example, the entire electrode can be placed on a different level from another electrode. In this way, additional connections can be placed without short circuits occurring.

[0051] A typical application for a substrate such as the substrate (100) is smart glazing, for example, in optical modulators, which can be applied to residential houses, offices, greenhouses, automobiles, etc. The transparency or reflectance level of the smart glazing can be electrically adapted. For example, in smart glazing, two substrates such as the substrate (100) will be stacked such that the surfaces to which two electrodes are applied face each other. A fluid containing particles is placed between the two substrates. Smart glazing embodiments are further discussed below. In an embodiment, electrodes, for example, two or more electrodes, are applied to one surface of each substrate. For example, to facilitate the stacking of three or more substrates, one or more electrodes may also be present on other surfaces of the substrate (100).

[0052] Some of the embodiments below illustrate examples of modulating transparency or reflectance levels. Optical modulators can be adapted for other optical effects. For example, if desired, the embodiments can be changed to different translucency levels instead of different transparency levels. If desired, the type of particles used in the embodiments can be changed to particles that differ, for example, in which wavelengths the particles absorb or reflect and how specular or diffusive the reflection is. For example, in the embodiments, the optical modulator can modulate different reflection levels. The particles can also emit light. Stacking multiple optical layers further increases the possibilities.

[0053] Having two sets of alternating main lines is sufficient to provide electrically adaptable glazing; due to the two alternating sets, the electric field at any part of the substrate can be controlled because the two opposing electrodes border the corresponding part from the two opposing faces.

[0054] Interestingly, the pattern of electrodes extending across the substrate can be created by a number of repeating building blocks. As illustrated in FIG. 1b, the electrodes on the substrate (100) are shown in four blocks, namely blocks (141, 142, 143, and 144), all of which are substantially identical. The number of building blocks may be greater than four. The building blocks are repeated across the substrate in two directions, for example, a first direction (191) shown horizontally in the drawing, e.g., the x-direction, and a second direction (192) shown vertically in the drawing, e.g., the y-direction. Using building blocks is advantageous because it enables manufacturing using a stepper machine; however, using building blocks is not strictly necessary.

[0055] For example, FIG. 1a schematically illustrates an example of an embodiment of a building block (140). The building block (140) includes a number of interdigitated electrodes extending in at least two directions across the building block. FIG. 1a shows four electrodes, namely electrodes (131-134). When building blocks are repeated across a substrate in two directions, the electrodes within the building block will form electrodes, for example, multiple main lines of electrodes. Note that building blocks are generally connected in a substrate-electrode design tool. Generally, a building block includes more than four electrode lines. For example, within the scope of embodiments, eight to twelve main lines are used. However, the number of electrode lines can be much greater. For example, a building block may include many short electrode lines near edges that connect to lines of other building blocks when the block is repeated. Taking these short branches into account, the number of lines can go up to, for example, 50. Clearly, when using larger building blocks, the number of electrode lines can also increase. In one embodiment, the number of electrode lines in the building block is 8 to 50, or 8 to 25, etc.

[0056] The electrodes formed by repeating building blocks are connected to drive buses. Generally, electrode lines within a building block are connected to the electrode lines of neighboring blocks by merging corresponding electrode lines; however, this is not strictly necessary, and connection zones connecting corresponding electrode lines may be inserted between repeating building blocks.

[0057] This step connects multiple main lines together, thereby forming a single electrode. FIG. 1b illustrates two connection zones (119 and 129) in which main lines belonging to the same electrode are connected to the drive bus (110) and the drive bus (120), respectively.

[0058] The electrodes illustrated in FIG. 1a are alternately indicated by dashed lines in the same dashed line style as FIG. 1b. In fact, in this example, a specific electrode of the building block in FIG. 1a will always belong to the first electrode or the second electrode, for example, as indicated in the dashed line style in this case. However, this is not necessarily the case. An electrode within the building block may be part of the first electrode or part of the second electrode. This may vary as a result of, for example, the parity of the number of electrodes within the building block, the repeating pattern of the building blocks, etc.

[0059] For example, a specific pattern of repeating building blocks can be used in an optical modulator having two electrodes, in which case alternating main lines can be assigned to the two electrodes. However, the same pattern of repeating building blocks can be used in an optical modulator having three electrodes, in which case every subsequent set of three main lines can be assigned to the three electrodes.

[0060] Furthermore, the building block illustrated in FIG. 1a is square, but this is not necessarily required. For example, the building block may be rectangular. In an embodiment, the building block shape(s) may form a so-called tessellation. For example, the building block may be a combination of triangles, hexagons, or even planar filling shapes.

[0061] As mentioned, FIGS. 1a and 1b are schematic. This is particularly true for the depiction of the electrodes. The electrode shown in FIG. 1a is straight, but in the embodiment, the electrode on the building block is more wavy, for example, curved. By adapting the shape of the electrodes, undesirable diffraction effects can be altered.

[0062] In an embodiment, the dimmable mirror includes a light modulator according to the embodiment. For example, the dimmable mirror includes a transparent substrate, an optical layer, and a reflective substrate. One or both of the substrates are according to the embodiment. The dimmable mirror may be electrophoretic. Generally, each substrate has two electrodes, but this is not necessarily required.

[0063] FIG. 1c schematically illustrates an example of an embodiment of the substrate (101). The substrate (101) is similar to the substrate (100) except that the main lines formed from electrodes on the building blocks are connected to the drive buses. In FIG. 1a, a connection zone is inserted between repeating building blocks and drive buses (110 and 120). In the connection zone, main lines belonging to the same electrode are connected to the same drive bus. In FIG. 1c, the drive bus is immediately adjacent to the building blocks. To avoid the drive bus being connected to the main lines of different electrodes, some of the building blocks are modified. The drive buses (110 and 120) may be configured as contact areas.

[0064] For example, a building block (141) may be a copy of a building block (140), but the electrode (134) is shortened so that the main line (122), of which the line (134) is part, is not connected to the bus (110). In FIG. 1c, the building blocks are substantially identical except that disconnection is introduced to some electrodes of the building blocks next to the drive bus to avoid the main line being connected to the drive bus. All building blocks shown in FIG. 1c are modified in this way, but in the embodiment, most of the building blocks, such as those not near the drive buses (110, 120), will not be modified.

[0065] FIG. 1d schematically illustrates an example of an embodiment of a substrate (102). In the embodiment, the electrodes within the building block each connect the same opposing faces of the building block. This results in the main lines formed by the electrodes on the building block connecting the opposing faces of the substrate. In this situation, having only two driving buses extending along the opposing faces of the substrate, for example, is sufficient to connect and drive the electrodes.

[0066] However, electrodes within a building block do not need to connect the opposing faces of the building block. Generally, all electrodes within a building block connect two faces of the building block, but these two faces do not need to be opposite. This is because the electrode can be continued by the next building block. In this situation, most main lines will still connect the same two opposing faces, but this may not occur at the edge of the substrate, as there are no additional building blocks there to continue the electrode. To enable more complex electrode designs on the building blocks, main lines can be connected to a drive bus from two faces, for example, from two faces of the substrate near the same corner of the substrate.

[0067] In FIG. 1d, a driving bus (110') extending along two sides of the substrate and a driving bus (120') extending along the other two sides of the substrate are shown.

[0068] The advantage of this configuration is that the drive buses can be made in the same plane. However, this is not strictly necessary. If desired, for example to further increase the design freedom for the building blocks, the drive buses can be connected from all three or four sides. Various examples are presented in this specification.

[0069] Note that electrodes, such as drive buses and / or main lines, are allowed to overlap. This is possible, for example, by creating a portion of dielectric material between the electrodes. For example, these overlapping electrodes may be partially or wholly located on different planes of the substrate.

[0070] For example, in an embodiment, a first electrode may be deposited. Then, a dielectric is deposited locally, and finally, a second electrode is deposited. The dielectric is arranged to at least cover the points where the first electrode and the second electrode intersect. A via may be used to connect to the lower first electrode, for example. The deposition of the electrodes may include the deposition of drive buses.

[0071] FIG. 1e schematically illustrates an example of an embodiment of the substrate (203). In FIG. 1e, the building block is copied multiple times.

[0072] Building block (211) is mirrored in the y-direction to form building block (221). Building block (221) is arranged immediately below building block (211). Building block (211) is mirrored in the x-direction to form building block (212). Building block (212) is arranged immediately to the right of building block (211). Building block (211) is mirrored in both the x-direction and the y-direction to form building block (222). For example, the mirroring may have the face of the building block as the mirroring axis.

[0073] By mirroring the building blocks, it is ensured that the driving buses of the same electrode are positioned side by side on the substrate.

[0074] FIG. 1f schematically illustrates an example of an embodiment of the substrate (204). In the substrate (204), building blocks are repeated across the substrate in different ways. A building block (251) is mirrored in the y-direction to form a building block (261). The building block (261) is arranged immediately below the building block (251). The building block (251) is point-reflected, for example, rotated 180 degrees to form a building block (252). The building block (252) is arranged immediately to the right of the building block (251). The building block (251) is mirrored in the x-direction to form a building block (262).

[0075] It is also possible to arrange building blocks without mirroring the pattern.

[0076] FIG. 1g schematically illustrates an example of an embodiment of an optical modulator illustrating spacers. One of the two substrates is illustrated with an electrode system, in this case, two interdigitated electrodes. For example, the other substrate of the optical modulator of FIG. 1g may have a similar design. Spacers are illustrated in FIG. 1g. One such spacer is labeled 151. Spacers are small structures placed around the substrates to maintain the two substrates at a constant distance. The spacers may be dielectric, for example, formed from the same material as one of the substrates. The spacers are examples of fluid distribution protrusions within the optical modulator.

[0077] FIGS. 2a through 2f schematically illustrate examples of substrates having interdigitated electrodes. These may be implemented on a substrate having two electrodes, for example by alternately connected electrodes. FIGS. 2a through 2d may also be implemented on a substrate having multiple electrodes, for example by connecting three or four or more electrodes in sequence.

[0078] FIGS. 2e and FIGS. 2f illustrate designs having two electrodes on the surface of a substrate. Either design can be modified to have only a single electrode on the surface of the substrate, for example, by removing one of the two electrodes. For example, this modified design can be used in an optical modulator using a substrate having a single electrode.

[0079] The described designs can be realized on a single plane without the electrodes intersecting. In particular, when these designs are connected to two drive buses, intersecting electrodes are not required. When more than two electrodes are used, or when more complex electrode patterns are used, the intersecting of electrodes may be used or even required. However, such intersecting is possible, for example, where a dielectric material can be arranged between the electrodes at the location where two electrode lines intersect. For example, such an insulator can be deposited at the intersection location. For example, the first electrode is within the first plane of the substrate, and the second electrode is within the second plane of the substrate.

[0080] Two substrates according to an embodiment can be combined to form an optical modulator. The optical modulator is particularly suitable for glazing. An exemplary embodiment of the optical modulator is shown below.

[0081] FIG. 3a schematically illustrates an embodiment of an optical modulator (10) that can be applied to smart glazing.

[0082] Patent application PCT / EP2020 / 052379 is referenced, which is incorporated herein by reference; this application comprises advantageous designs for optical modulators, which may be further improved, for example, by including electrodes, building blocks, and / or substrates as described herein.

[0083] The optical modulator (10) may be electronically switched between a transparent state and a non-transparent state, or between a non-reflective state and a reflective state. The optical modulator (10) comprises a first substrate (11) and a second substrate (12) arranged facing each other. On the inner surface of the first substrate (11), at least two electrodes are applied: electrodes (13a, 13b) are shown. These at least two electrodes are collectively referred to as electrodes (13). On the inner surface of the second substrate (12), at least two electrodes are applied: electrodes (14a, 14b) are shown. These at least two electrodes are collectively referred to as electrodes (14). On one or more of the substrates (11 and 12), one or more contact areas may be provided to enable electrical connection to at least one electrode applied on the substrate(s).

[0084] A fluid (15) is provided between the substrates. The fluid comprises particles (30), such as nanoparticles and / or microparticles, and the particles are electrically charged or can be charged. For example, the particles may inherently possess a charge on the surface of the particles. For example, the particles may be surrounded by charged molecules. The fluid may be a liquid.

[0085] The electrodes are arranged so that, depending on the applied electric field, the particles (30) move toward the electrodes or away from the electrodes. Optical properties, particularly the transparency or reflectivity of the optical modulator, depend on the position of the particles (30) in the fluid. For example, a connection for applying an electromagnetic field to the electrodes may be provided.

[0086] The optical modulator (10) may be provided with fluid distribution protrusions toward an optical layer, for example, on a first substrate (11) and / or on a second substrate (12).

[0087] The electrodes (13 and 14) are schematically illustrated in the drawings. They can be implemented in a number of ways, for example, as shown in FIG. 2.

[0088] In the example, the substrate (11) and the substrate (12) may be optically transparent outside the electrodes and may generally have greater than 95% transparency at relevant wavelengths, e.g., greater than 99% transparency. When the electrodes are taken into account, the transparency may be much lower, e.g., 70%. The term “optical” may, where applicable, relate to wavelengths visible to the human eye (about 380 nm - about 750 nm), and, where applicable, may relate to a broader range of wavelengths including infrared (about 750 nm - 1 μm) and ultraviolet (about 10 nm - 380 nm) and partial selections thereof. In an exemplary embodiment of the optical modulator, the substrate material is selected from glass and polymer.

[0089] In another example, one substrate, such as the bottom substrate (12), may be reflective or partially reflective, and the top substrate (11) is transparent. Optical properties, particularly the reflectivity of the optical modulator, depend on the position of the particles (30) in the fluid. When the panel is in an open state (vertical drive), the particles will mostly be located between the opposing electrodes of the two substrates so that incident light can pass through the transparent top substrate and the optical layer relatively unimpeded and is reflected or partially reflected on the bottom substrate.

[0090] The distance between the first substrate and the second substrate is generally less than 30 μm, for example, 15 μm. In an exemplary embodiment of the optical modulator, the distance between the first substrate and the second substrate is less than 500 μm, preferably less than 200 μm, preferably less than 100 μm, more preferably less than 50 μm, for example, less than 30 μm.

[0091] In the example, the modulator may be provided with a flexible polymer, and the rest of the device may be provided with glass. The glass may be rigid glass or flexible glass. If necessary, a protective layer may be provided on the substrate. If more than one color is provided, more than one flexible polymer layer may be provided. The polymer may be polyethylene naphthalate (PEN), polyethylene terephthalate (PET) (optionally having a SiN layer), polyethylene (PE), etc. In an additional example, the device may be provided with at least one flexible polymer. Thus, the modulator may be attached to any surface, for example, by using an adhesive.

[0092] The particles (30) can be adapted to absorb light and prevent specific wavelengths from passing through. The particles (30) can reflect light; for example, the reflection can be specular, diffusive, or intermediate. The particles can absorb some wavelengths and reflect others. The particles can also, or instead, emit light using, for example, phosphorescence, fluorescence, etc. Even fluids can emit light, and this emission rate is modulated by changing the position of the particles.

[0093] In an exemplary embodiment of the optical modulator, the size of the nanoparticles is 20 to 1000 nm, preferably 20 to 300 nm, more preferably less than 200 nm. In an exemplary embodiment of the optical modulator, the nanoparticles / microparticles may comprise a coating on a pigment and preferably comprise a core. In an exemplary embodiment of the optical modulator, the coating of the particles is made of a material selected from conductive and semiconducting materials.

[0094] In an exemplary embodiment of the optical modulator, the particles are adapted to absorb light having wavelengths of 10 nm to 1 mm, such as 400 to 800 nm, 700 nm to 1 μm, and 10 to 400 nm, and / or are adapted to absorb (filter) a portion of light having a wavelength range within 10 nm to 1 mm, and combinations thereof.

[0095] In an exemplary embodiment of the optical modulator, the particles are electrically charged or can be charged. For example, the charge on the particles is 0.1e to 10e (5 x 10⁻⁶) per particle. -7 -0.1 C / m 2 It can be.

[0096] In an exemplary embodiment of the optical modulator, the fluid is 1-1000 g / m³ 2 , preferably 2-75 g / m² 2 , more preferably 20-50 g / m² 2 , for example, 30-40 g / m² 2 It exists in an amount. A major advantage is that much smaller amounts of fluid and, likewise, particles can be used with the current layout.

[0097] In an exemplary embodiment of the optical modulator, the particles are 0.01–70 g / m² 2 , preferably 0.02-10 g / m² 2 , for example 0.1-3 g / m² 2 It exists in an amount of

[0098] In an exemplary embodiment of the light modulator, the particles have colors selected from cyan, magenta, and yellow, colors selected from black and white, and combinations thereof.

[0099] The optical modulator can also be configured to modulate only non-visible light, such as UV or near-IR, or mainly non-visible light, for example, within the range of about 10 nm to 380 nm and about 750 nm to 1 μm, respectively.

[0100] In an exemplary embodiment of the optical modulator, the fluid comprises one or more of a surfactant, an emulsifier, a polar compound, and a compound capable of forming hydrogen bonds.

[0101] The fluid (15) may be a nonpolar fluid with a dielectric constant of less than 15. In an exemplary embodiment of the optical modulator, the fluid has a relative permittivity of less than 100, preferably less than 10, e.g., less than 5. It has. In an exemplary embodiment of the optical modulator, the fluid (15) has a dynamic viscosity greater than 10 mPa·s.

[0102] The electrodes (13a, 13b) and electrodes (14a, 14b) are in a fluid-fluid contact state. The fluid may be in direct or indirect contact with the electrodes, and, for example, the fluid may be in contact with a second medium together with the electrodes, such as through a porous layer. In an embodiment, the electrodes cover about 1-30% of the substrate surface. In an embodiment, the electrodes comprise an electrically conductive material having a resistivity of less than 100 nΩm (at 273K; for comparison, commonly used ITO has 105 nΩm), which is 1*10 at 20°C. 7 It is similar to electrical conductivity exceeding S / m.

[0103] In one embodiment of the optical modulator, the electrodes comprise copper, silver, gold, aluminum, graphene, titanium, indium, and combinations thereof, preferably copper. The electrodes may be in the form of microwires embedded in a polymer-based substrate; for example, copper microwires.

[0104] As a connection for applying an electromagnetic field to the electrodes, the electromagnetic field applied to the electrodes provides for the movement of nanoparticles and microparticles from the first electrode to the second electrode and vice versa. A connection for applying an electromagnetic field to the electrodes may be provided. For example, in an exemplary embodiment of the optical modulator, the electric current is -100 to +100 μA, preferably -30 to +30 μA, more preferably -25 to +25 μA. For example, a power supply may be electrically connected to at least two electrodes. The power supply may be adapted to provide waveform power. At least one of the amplitude, frequency, and phase may be adaptable to provide different states in the optical modulator. For example, these aspects of power may be adapted by a controller (16). The controller (16) may be connected to the contact areas of the optical modulator.

[0105] The optical modulator (10) may include one or more segments, and the segment is a single optically switchable entity that may vary in size. Substrates surround a volume, which may be at least partially a segment.

[0106] The device may include a driver circuit for changing the appearance of (individual) segments by applying an electromagnetic field. In this way, the appearance of the optical modulator, or the appearance of one or more parts thereof, may also be changed. For example, the segment is at least 1 mm 2 It can have an area. This design enables stacking to allow more colors; for example, for full-color applications, a stack of two or three modulators can each provide most or all colors.

[0107] Having one or more segments allows the optical modulator to be controlled locally; this is advantageous for some applications but is not strictly necessary. For smart glazing, an optical modulator with or without segments may be used. For example, when applied to smart glazing, transparency or reflectance may be controlled locally to block sun-patches without reducing transparency or reflectance, for instance, across the entire window. The segments may be relatively large and may have a diameter, for example, of at least 1 mm or at least 1 cm.

[0108] In an exemplary embodiment of the optical modulator, substrates (11, 12) are aligned and / or electrodes (13, 14) are aligned. For example, electrodes (13a, 13b) and electrodes (14a, 14b) may be aligned to face each other. In the aligned substrates, the electrodes on the different substrates overlap each other when viewed from a direction orthogonal to the substrates. When the optical modulator is disassembled and the substrates are all arranged so that the electrodes face upward, the electrode patterns are mirror images of each other.

[0109] Aligning the substrates can increase the maximum transparency or reflectance of the optical modulator, and on the other hand, when selecting an optical modulator for more criteria than the range of transparency or reflectance, it may be better not to align the two substrates or not to align them completely. Optical modulators can be stacked. For example, two stacked optical modulators can be made of three substrates, and the intermediate substrate has electrodes on both surfaces. In an embodiment of the optical modulator, at least one substrate (11, 12) of the first optical modulator is optionally identical to the substrate (11, 12) of at least one second optical modulator. In the case of stacked modulators, alignment can also increase the maximum transparency or reflectance, but it may be disadvantageous to other considerations, such as diffraction.

[0110] FIG. 3b schematically illustrates an example of an embodiment of an optical modulator (40). The optical modulator (40) is similar to the optical modulator (10) except that it includes a plurality of optical layers; in the example illustrated, it includes two optical layers. More than two optical layers may exist. Each optical layer is arranged between two substrates. The optical modulator (40) can be considered as a stack of two substrate optical modulators as in FIG. 3a. As illustrated, the optical modulator (40) includes three substrates: a first substrate (41), a second substrate (42), and a third substrate (43). An optical layer exists between the substrates (41 and 42), and an optical layer exists between the substrates (42 and 43). The optical layers may be similar to the optical layers within the optical modulator (10). A controller (46) is configured to control the electric current on the electrodes of the substrates. For example, in FIG. 3b, the controller (46) can be electrically connected to at least 4 times 2, i.e., 8 electrodes.

[0111] Interestingly, the particles within the multiple optical layers may be different, so that multiple layers can be used to control more optical properties of the optical modulator. For example, the particles within the different optical layers may absorb or reflect at different wavelengths and may have different colors, for instance. This can be used by the controller (46) to generate different colors and / or different color intensities on the panel. For example, a 4-substrate panel may have three optical layers, each having different colored particles, such as cyan, yellow, and magenta particles. By controlling the transparency or reflectance for the different colors, a broad color spectrum can be generated.

[0112] For example, as in the embodiment, two or more patterns may be provided on the surfaces of the substrates facing another substrate. For example, the outer substrates (41 and 43) may have electrodes received only on the inner surface, whereas the inner substrate, such as substrate (42), may have electrodes on both surfaces.

[0113] The substrates (41 and 42) can be considered together as an embodiment of an optical modulator. Likewise, the substrates (42 and 43) can be considered together as an embodiment of an optical modulator.

[0114] One or more of the substrates (41, 42, and 43) may be provided with a contact area for electrical connection to electrodes, for example, for control by a controller (46).

[0115] Fluid distribution protrusions may be provided in the optical modulator (40), for example, on a first substrate (41) facing a second substrate (42), on a second substrate (42) facing the first substrate (41), on a second substrate (42) facing a third substrate (43), and / or on a third substrate (43) facing the second substrate (42).

[0116] FIG. 3c schematically illustrates an example of an embodiment of a vehicle (20) having smart glazing for windows (21). This is a particularly advantageous embodiment, as the level of incident light can change frequently and rapidly during driving. Using smart glazing in a vehicle has the advantage that light levels can be maintained at a constant level by controlling the transparency of the vehicle windows. Furthermore, the reduced diffraction effect improves safety by reducing driver distraction. The vehicle (20) may include a controller configured to control the transparency or reflectivity of the windows (21).

[0117] Smart glazing can also be used in other glazing applications, particularly where the amount of incident light is variable, such as in buildings, offices, houses, greenhouses, and skylights. Skylights are windows arranged in the ceiling to allow sunlight to enter a room.

[0118] The optical modulator may have two optical states, such as a transparent state and a non-transparent state, or a non-reflective state and a reflective state. The optical modulator, such as the optical modulator (10) or the optical modulator (40), is,

[0119] By applying an alternating current between at least a first electrode and a second electrode on a first substrate and / or between a first electrode and a second electrode on a second substrate, an alternating current voltage is generated on at least one of the first substrate and the second substrate to switch to a second optical state, e.g., a non-transparent state or a reflective state, and

[0120] By applying alternating current between a first electrode on a first substrate and a first electrode on a second substrate and / or between a second electrode on a first substrate and a second electrode on a second substrate, an alternating current voltage is generated between the first substrate and the second substrate, and the first substrate may be configured to switch to a first optical state, such as a transparent state or a non-reflective state.

[0121] The electrode pattern on the first substrate is at least partially arranged in the same pattern as the second electrode on the second substrate. Generally, the electrodes face each other, but the patterns of the first electrode and the second electrode can also be shifted relative to each other.

[0122] A protective coating may be provided on at least a portion of the inner surface area of ​​at least one of the first substrate and the second substrate.

[0123] The driving signal applied to the electrodes generally has a varying voltage. For example, the power supply may be operated at an AC frequency to switch between a transparent state and a non-transparent state. Such a signal may have a frequency between, for example, 1 to 1000 Hz. A balanced electrolytic current can be obtained by continuously switching the polarity of opposing charged electrodes on the first substrate and the second substrate and / or between the first substrate and the second substrate.

[0124] FIGS. 4a and 4b schematically illustrate side views of an embodiment of an optical modulator in use. Only electrodes are shown in these figures. Contact area(s) are not separately illustrated in these figures.

[0125] Applying an electric field to electrodes on substrates causes an electric force on the particles. Using this effect, the particles can be moved, thereby causing different transparency or reflectance states in the optical modulator. A controller can control the electric field, such as the amplitude, frequency, and phase of the electric field. In an embodiment, the controller is connected to at least four electrodes, two for each substrate. However, more electrodes may be used and connected to the controller; for example, more than two electrodes may be used on the substrate to better fine-tune grayscale and drive to non-transparent or reflective states. Multiple electrodes may also be used to support multiple segments on the substrate.

[0126] FIG. 4a illustrates an optical modulator to which no electric field is applied. In FIG. 4a, no electric force has yet been applied to the suspended particles (30) in the fluid (15).

[0127] In the configuration illustrated in FIG. 4a, the conductive electrode pattern arranged on the top substrate is completely or substantially aligned with the conductive electrode pattern on the bottom substrate. The conductive electrode pattern may be deposited on a transparent or (partially) reflective glass substrate, or embedded within a plastic substrate, etc.

[0128] Alignment between the top and bottom electrode patterns contributes to a wider range of achievable transparency or reflectance levels. However, alignment is not necessary, as similar effects can be obtained without it. Without alignment, a similar range of transparency or reflectance is achieved.

[0129] Note that in these examples, the top substrate and bottom substrate are referred to to denote the substrates higher or lower on the page. The same substrates may also be referred to, for example, as the front substrate and the back substrate, because in glazing applications, the substrates will be aligned vertically rather than horizontally.

[0130] FIG. 4b illustrates an optical modulator in which, for instance P1, a potential +V1 is applied to each microwire electrode on the top substrate, while a negative voltage, for example -V1, is applied to each microwire electrode on the bottom substrate. Thus, in this case, the same positive potential is applied to all electrodes (13), and the same negative potential is applied to the electrodes (14). The difference in potential causes negatively charged particles to flow near the electrodes on the top substrate, where the particles will be substantially aligned with the top electrodes. As a result, if both the top substrate and the bottom substrate are transparent, the transparency of the optical modulator (10) will be increased. Likewise, if, for example, the top substrate is transparent and the bottom substrate is reflective, the reflectivity of the optical modulator (10) will be increased. If the solution contains positively charged particles, those particles will flow near the electrodes of the bottom substrate, where they will be substantially aligned with the bottom electrodes.

[0131] In the second instance P2 of the on-state, when the voltages of the top electrodes and the bottom electrodes are inverted in contrast to instance P1, similar transparency can be achieved. In instance P2, the voltage of each electrode of the top substrate is now supplied at a negative potential -V1, while the voltages of the aligned electrodes of the bottom substrate are supplied at a positive potential. This state is similar to the state shown in FIG. 4b, but the top substrate and the bottom substrate are inverted. In this configuration, the transparency of the optical modulator (10) is also high. If reflective particles are used, the reflectivity is low.

[0132] Interestingly, transparency or non-reflectivity can be maintained while reducing corrosive damage to the electrodes by switching between a positive potential (and a negative potential on the electrodes (14)) on the top substrate, for example as shown as electrodes (13) in FIG. 4b, and a positive potential on the electrodes on the bottom substrate, for example as shown as electrodes (14) in FIG. 4b. This alternating electric field can be achieved by applying alternating electric potentials to the top and bottom electrodes.

[0133] Applying an AC waveform is optional, but it is a useful means of increasing the lifespan of the optical modulator by reducing corrosion. Corrosion can occur, for example, when using copper electrodes, because copper ions dissolve in an ionic fluid on one substrate and flow to the electrode on the opposite substrate to be deposited there. By applying a waveform, the direction of copper ion movement is frequently reversed, thereby reducing corrosion damage. Between two instances P1 and P2, the corrosion current between the two substrates is balanced or substantially balanced, for example, by more than 95%, such that, for example, as the corrosion rate of the electrode on the top plate occurs, there is a balanced deposition of copper on the bottom electrode between each time instance P1, and the opposite is true in instance P2. Therefore, particles continuously transition or move between the top electrode and the bottom electrode, and the optical modulator or smart window is always in the ON state, while the dynamic electrolysis current between the top electrode and the bottom electrode is constant, thereby resulting in no or negligible net loss of electrode material on the top and bottom substrates.

[0134] FIG. 4c illustrates how a state in which transparency is reduced or reflectance is increased can be obtained. Alternating voltages are applied on the same substrate. For example, in an embodiment, a potential +V2 is applied to the first electrode, and the next adjacent electrode has a potential -V2 of opposite polarity, as illustrated in FIG. 4c. This can be obtained by applying a potential +V2 to electrode (13a) and a potential -V2 of opposite polarity to electrode (13b). On the opposing substrate, a potential +V2 can be applied to electrode (14a) and a potential -V2 of opposite polarity can be applied to electrode (14b). For example, the electrodes can be arranged so that the electrodes on the substrates are aligned; the electrode on the top substrate has an opposing electrode on the bottom substrate, and vice versa. For example, to reduce transparency or increase reflectance, the opposing electrode may receive the same potential, while the adjacent electrodes receive potentials of opposite polarity. An embodiment is illustrated in FIG. 4c, where four electrodes are labeled with reference numbers (13a, 13b, 14a and 14b), and the remaining electrodes alternate.

[0135] By using this AC drive cycle between the top and bottom substrates, diagonal and lateral electric fields are generated between the two substrates, thereby causing irregular diffusion of particles and creating a closed state of the optical modulator. As a result of this configuration, particles move diagonally and laterally between the top and bottom substrates, and the diffusion of particles into the visible aperture of the optical modulator contributes to the closed opaque state of the optical modulator.

[0136] Regarding the transparent state illustrated in FIG. 4b, a waveform may be applied to the electrodes, for example, so that the electrodes illustrated as positive potential in FIG. 4b become negative, and vice versa. As in FIG. 4b, applying a waveform, for example, between electrodes (13a and 13b) and between electrodes (14a and 14b) reduces corrosive damage to the electrodes. In an embodiment, the electrodes (14), e.g. electrodes (14a, 14b), are reflective, whereas the electrodes (13), e.g. electrodes (13a, 13b), may or may not be reflective.

[0137] The AC driving cycle can be implemented by using an interdigitated line configuration that combines the uppermost electrode configuration and the lowermost electrode configuration shown in the plan views of FIG. 1a, FIG. 1b, FIG. 2a to FIG. 2f, etc.

[0138] In FIGS. 4b and 4c, the degree to which transparency or reflectance increases or decreases depends on the difference in voltage and frequency. By varying the voltage difference, the amount by which transparency or reflectance increases or decreases, respectively, is controlled. For example, a curve representing light transmittance versus voltage can be determined and, for instance, measured. To obtain a specific level of light transmittance, for instance, a specific level of transparency, for instance, a specific grayscale level, a corresponding voltage, for instance, an AC voltage, can be applied. Intermediate levels between transparent and non-transparent states can be obtained by interpolating signals for transparent or non-transparent states. Similarly, a curve representing light reflectance versus voltage can be determined and, for instance, measured. To obtain a specific level of reflectance, a corresponding voltage, for instance, an AC voltage, can be applied. Levels between reflected and non-reflective states can be obtained by interpolating signals for reflected or non-reflective states.

[0139] Different electrode patterns may be used in optical modulators. Each electrode pattern can provide a range of grayscale levels, such as transparency or reflectance, that the optical modulator can achieve. However, a specific range of grayscale for any given electrode pattern may differ from that of another electrode pattern. In other words, while different patterns may provide increased transparency or reflectance, or increased opacity, the precise response to a driving signal depends on many factors, including the specific pattern used. Variations in the optical properties of the optical modulator may result in fine resolution, such as less than 1 mm. It should be noted that pixelation of the optical modulator is not required to achieve different optical patterns, such as logos, visible in the optical modulator.

[0140] This effect can be used to embed visible images into an optical modulator by locally varying the electrode patterns on the substrates of the optical modulator. For example, different electrode patterns may locally produce grayscales that have a permanent offset from each other. For example, by locally varying the electrode pattern or its pitch, the maximum transparency or reflectance may be altered.

[0141] The result is an area on the light modulator having different grayscale intensities, e.g., different grayscales, or different colors. However, the area may have the same color-point. In an embodiment, the areas may be switched along with the rest of the window at different rates. For example, even if the same voltage is applied to the electrodes within two different areas, different electrode patterns result in different transparency states, e.g., different transmittance levels. For example, a curve representing transmittance versus voltage may be shifted. For example, if voltage control changes in the same way in both areas, light transmittance may change in both areas, but the amount of change may be different. The area may also be made to be less responsive to a driving signal by reducing the density of the electrodes; in particular, the area may be made not to be switched at all, for example, by not applying electrodes to the area.

[0142] For example, the electrode material can be copper, aluminum, gold, indium-tin oxide (ITO), etc. ITO is transparent, whereas Cu / Al is reflective; thus, by using different electrode materials, different appearances can be obtained regardless of voltage driving. Similarly, different materials with different resistances will generate different electric fields. For example, ITO will have a smaller electric field even when driven at the same voltage.

[0143] An embodiment of a method for modulating light comprises applying an electric potential to a plurality of electrodes applied to two opposing substrates according to the embodiment, wherein the application of the electric potential causes modulation of light passing through the substrates by acquiring an electromagnetic field between the plurality of electrodes that provides electrophoretic movement of particles toward or from one of the plurality of electrodes, and the two opposing substrates are as in the embodiment.

[0144] The optical modulator (10) may be provided with fluid distribution protrusions toward an optical layer, for example, on a first substrate (11) and / or on a second substrate (12).

[0145] Various operating modes are supported by embodiments of the 4-electrode optical modulator system.

[0146] Horizontal drive

[0147] Horizontal driving is a mode in which lateral electric fields are generated along the substrate. The optical modulator can reduce transparency by applying alternating voltages on interdigitated electrodes, causing particles within the optical layer to move parallel to the substrate.

[0148] Vertical drive

[0149] Vertical driving is a mode in which particles are aligned orthogonally to the substrates. Opposing electrodes on opposite substrates receive different voltages.

[0150] Maintain grayscale

[0151] The optical modulator driving system can apply zero voltage to the electrodes for most of the time, but when the grayscale drops due to particle dispersion, the electrodes can be driven for a short time as in vertical driving.

[0152] In all three modes, the drive can use DC or AC signals. Preferably, AC signals are used.

[0153] Drawings, claims, and descriptions regarding fluid distribution protrusions are presented below. Nevertheless, embodiments of an optical modulator having fluid distribution protrusions can be manufactured on the same machine, such as a one-drop fill (ODF) machine, using the same processes as an optical modulator having a low-pressure layer to obtain an energy-efficient optical modulator, for example, in a limited size and weight.

[0154] It would be advantageous to have an improved optical modulator and an improved substrate that can be used therein.

[0155] Some embodiments relate to an optical modulator. The optical modulator may include an optical layer extending between a first substrate and a second substrate, wherein the second substrate is arranged opposite to the first substrate. Particles in a fluid within the optical layer may be modulated, thereby changing the optical properties of the optical modulator. The optical modulator may be configured to modulate light passing through the optical layer by applying an electric potential to at least one electrode applied to at least the first substrate on a surface facing the second substrate, wherein the electric potential causes modulation of the electric field within the optical layer, thereby providing electrophoretic and / or dielectrophoretic migration of particles within the optical layer. The fluid within the optical layer may include ink, and / or particles within the optical layer may include ink particles.

[0156] In a general embodiment, two electrodes are applied on the inner surface of each of the substrates. Other optical modulators may also be applied as described herein. The optical characteristics of the optical modulator can be changed by applying an electric potential to at least one electrode.

[0157] For example, at least one electrode may be arranged across the substrate in multiple lines that do not necessarily have to be straight. The multiple electrodes are generally interdigitated and, for example, arranged alternately on a plane.

[0158] The optical layer may contain a fluid, such as a liquid. The fluid may contain particles. By applying an electric potential to at least one electrode, modulation of the electric field within the optical layer is induced, and the modulation of the electric field provides electrophoretic and / or dielectrophoretic movement of particles within the optical layer, thereby causing modulation of light passing through the substrates. Generally, the first substrate and the second substrate are transparent. The first substrate and the second substrate generally have the same dimensions. The substrates of the optical modulator may be glass, such as tempered glass, or plastic. For example, the distance between the substrates of the optical modulator may be up to 100 micrometers, e.g., up to 50 micrometers, e.g., up to 30 micrometers.

[0159] Electrode(s) are generally patterned using a photolithography process.

[0160] The optical modulator may further include a plurality of fluid distribution protrusions for controlling the flow of fluid within the optical layer. The plurality of fluid distribution protrusions may be distributed across a region of the surface of at least one of the first substrate and the second substrate, and the region is mm 2 The density of at least 10 fluid distribution protrusions per substrate is, and / or the combined area of ​​the fluid distribution protrusions is at least 0.1% of the surface of the first substrate.

[0161] For example, the distribution of multiple fluid distribution protrusions may be as follows. The surface region may include the entirety of at least one of the first substrate and the second substrate. The density of the fluid distribution protrusions is mm 2 There may be at least 50 of them, and / or the combined area of ​​the surface zones may be at least 0.2% of the surface of the first substrate. For example, the combined area may be at least 0.3% of the surface of the first substrate.

[0162] The distribution may span multiple regions of fluid distribution protrusions of varying densities and / or coverages. The distribution may span multiple regions of fluid distribution protrusions, and the fluid distribution protrusions have a distribution of shapes, heights, and / or sizes. For example, the fluid distribution protrusions may be triangular, rectangular, cylindrical, and / or hill-shaped. For example, among the plurality of fluid distribution protrusions, the fluid distribution protrusions may have two or more different heights. For example, fluid distribution protrusions of a first height are contained in a first substrate, and fluid distribution protrusions of a second height are contained in a second substrate.

[0163] The fluid distribution protrusions among the plurality of fluid distribution protrusions may have a cross-sectional diameter of at least 1 μm and / or a height of at least 6 μm, and / or the sum of at least some of the heights of the corresponding fluid distribution protrusions among the plurality of fluid distribution protrusions in the first substrate and the second substrate may be equal to the width of the gap between the first substrate and the second substrate.

[0164] The distribution may be such that the fluid distribution protrusions in the zone are spaced at least 20 μm apart from each other and / or at most 1 mm apart from each other. The distribution may be such that at least 10%, preferably 50%, and more preferably 80% of the plurality of fluid distribution protrusions in the zone on the surface of the first substrate are aligned perpendicularly with the corresponding fluid distribution protrusions on the second substrate, or are shifted parallel to the second substrate with respect to the corresponding fluid distribution protrusions on the second substrate. Such shift of the fluid distribution protrusions parallel to the second substrate with respect to the corresponding fluid distribution protrusions on the second substrate may include, for example, a distance equal to at least the width of the fluid distribution protrusions among the plurality of fluid distribution protrusions. The shift may include, for example, a distance equal to up to twice the maximum diameter of the cross-section of the fluid distribution protrusions among the plurality of fluid distribution protrusions. The shift may include, for example, a distance of at least 0.5 μm.

[0165] Having a distribution of fluid distribution protrusions across a region of the surface of at least one of the first substrate and the second substrate — the region is mm 2 A density of at least 10 fluid distribution protrusions per unit and / or a combined area of ​​the fluid distribution protrusions of at least 0.1% of the surface of the first substrate — may be advantageous to an optical modulator in the following ways. Generally, a distribution involving fluid distribution protrusions of a relatively high density compared to the prior art can improve the reliability performance and / or lifespan of the optical modulator.

[0166] A distribution involving fluid distribution protrusions of relatively high density compared to conventional technology can restrict and control fluid flow in an improved manner during process and device operations. The fluid can be distributed more uniformly, efficiently, and / or in other improved ways, for example, more homogeneously. The distribution can restrict the fluidity of the fluid within the device, which may be, for example, ink, which can be advantageous for maintaining a homogeneous distribution of chemicals within the ink. Due to this distribution, sedimentation, such as ink sedimentation, may occur less frequently. By restricting and / or avoiding fluid sedimentation and maintaining a homogeneous distribution of chemicals within the fluid, the lifespan of the optical modulator can be increased.

[0167] Furthermore, a distribution involving fluid distribution protrusions of relatively high density compared to conventional technology can improve process conditions during the manufacturing and / or use process of the optical modulator, as the distribution can contribute to the stability of the optical modulator during the process. In particular, the processing of one-drop filling (ODF) that can be used to manufacture electrophoretic optical modulators, such as displays for liquid crystal displays (LCDs), can be supported. Moreover, a distribution involving fluid distribution protrusions of relatively high density compared to conventional technology can contribute to the mechanical robustness of the optical modulator, as the first and second substrates may be less likely to break, shift, and / or tilt in an undesirable manner when the process conditions under which the manufacturing and / or use process of the optical modulator takes place may change. In particular, by increasing capillary force, a distribution involving fluid distribution protrusions of relatively high density compared to conventional technology can limit the bulging effect that may occur in glass substrates that can be implemented in the vertical orientation of the substrates, for example, in a window setting.

[0168] In an embodiment, the fluid distribution protrusions may include spacers arranged between a first substrate and a second substrate. The spacers may be applied to at least the first substrate on a surface facing the second substrate. The spacers may maintain a cell gap between the first substrate and the second substrate. In an embodiment, the spacers may be applied to the first substrate and / or the second substrate on a surface facing the optical layer. The spacers may be arranged between the second substrate (12) and the first substrate (11); and during manufacturing, the spacers may be applied on the second substrate (12), or on the substrate (11), and / or partially on both. The spacers may be very thin. For example, in an embodiment, the ratio between the diameter of the spacers and the height of the spacers is at most 1, or at most 3 / 4, or at most 1 / 2, or at most 1 / 4. The spacers may be manufactured in a number of ways. For example, spacers can be obtained by an imprinting process, an embossing process, and / or an etching process. Spacers can be created using a photolithography process. These spacers are referred to as photospacers. Using photospacers can enable precise placement of spacers, smaller dimensions, higher density, and wider coverage. This can maintain greater stability and flatness of the device. In an embodiment, the spacers are photospacers and are UV-curable, for example, composed of a UV-curable resin. In an embodiment, the spacers are photospacers and are composed of a UV-curable resin selected from the group consisting of epoxy-based, acrylic-based, polyurethane-based, and silicone-based resins. For example, the following process may be used to manufacture photospacers. First, a UV-curable material is applied to predetermined spacer locations on a substrate.This step does not need to be too precise, as more UV-curable material than is required for the spacers may be deposited. Then, secondly, the UV-curable material is exposed to ultraviolet (UV) light through a photomask to cure the spacers. After curing, any additional uncured material can be removed, for example, by washing. In an embodiment, the alignment of the spacers can be controlled. For example, in an embodiment, the first substrate and / or the second substrate may include visible micropattern elements, and all or part of the spacers may be aligned with the visible micropattern elements. This reduces the optical visibility of the spacers. The visible micropattern elements may be electrodes, particularly electrodes within an optical modulator. The visible micropattern elements may also include elements other than electrodes. For example, the visible micropattern elements may be visible patterns applied for aesthetic reasons. For example, visible micropattern elements may be patterns configured to be visible to birds in order to cause birds to avoid flying into the light modulator.

[0169] In an embodiment, the optical modulator may be sealed: a seal may be applied between a first substrate and a second substrate, positioned at the edge of at least one of the substrates. The seal may seal the optical layer. One method for performing the seal is to use a UV-curable seal, such as a UV-curable resin as indicated above. The UV-curable seal may be applied around the edges between at least one insulating substrate and the optical modulator and / or between the substrates of the optical modulator. For example, the seal may be applied on the first substrate facing the optical layer before the second substrate is applied. The distribution of a plurality of fluid distribution protrusions may be such that at least 10%, preferably 50%, and more preferably 80% of the plurality of fluid distribution protrusions are positioned at the edge around the seal.

[0170] In an embodiment, the distribution of a plurality of fluid distribution protrusions may be such that at least 10%, preferably 50%, and more preferably 80% of the plurality of fluid distribution protrusions are aligned with at least one electrode. In this distribution, the area where the fluid distribution protrusions may be distributed may overlap with the area where at least one electrode may be distributed, and the fluid distribution protrusions may be obscured by at least one electrode. At least one electrode may be wholly or partially non-transparent. Then, this distribution of fluid distribution protrusions may wholly or partially avoid any possible negative effect, such as an increase in diffraction effects, that the fluid distribution protrusions and / or their distribution might otherwise have on the optical properties of the optical modulator device, and / or may be beneficial to the contrast properties of the optical modulator device. A distribution of a plurality of fluid distribution protrusions such that at least 10%, preferably 50%, and more preferably 80% of the plurality of fluid distribution protrusions are aligned with at least one electrode may be beneficial to the optical performance of the optical modulator.

[0171] One aspect is a substrate for use in an optical modulator, the substrate may include at least one electrode applied to the substrate and a plurality of fluid distribution protrusions, wherein the plurality of fluid distribution protrusions are mm within a region of the surface of the substrate 2 It can be distributed across the zone with a density of at least 50 fluid distribution protrusions per unit.

[0172] Another aspect is a method for modulating light, the method may include the step of applying an electric potential to at least one electrode, the at least one electrode may be applied to at least one of two opposing substrates, and at least one of the two opposing substrates may be in accordance with the embodiment. Applying an electric potential may cause modulation of an electric field within an optical layer, the optical layer may extend between two opposing substrates, the optical layer may include a fluid containing particles, and may provide electrophoretic and / or dielectrophoretic movement of particles within the optical layer, and this movement may cause modulation of light passing through the optical layer.

[0173] Another aspect is a method for manufacturing an optical modulator according to an embodiment, the method may include the steps of providing a first substrate according to an embodiment, applying a seal along the edge of the first substrate, providing a fluid containing particles on the first substrate within a sealed area, and providing a second substrate facing the first substrate, thereby forming an optical layer between the first substrate and the second substrate, and the optical layer may be sealed by the seal.

[0174] The present specification describes embodiments of optical modulators comprising a plurality of fluid distribution protrusions, wherein the plurality of fluid distribution protrusions are arranged to control the flow of fluid within the optical layer of the optical modulator, and the plurality of fluid distribution protrusions are distributed across a region of the surface of at least one of a first substrate and a second substrate, and the region is mm 2 The density of at least 10 fluid distribution protrusions per layer and / or the combined area of ​​the fluid distribution protrusions is at least 0.1% of the surface of the first substrate.

[0175] These fluid distribution protrusions are useful for improving fluid flow within the optical layer, thereby limiting fluid flow within the optical layer and reducing possible sedimentation of fluid, e.g., ink. Generally, a distribution involving fluid distribution protrusions of relatively high density compared to conventional technology can improve the reliability performance and / or lifespan of the optical modulator in this way.

[0176] The optical modulator comprises a first substrate, a second substrate arranged opposite to the first substrate, and an electrode system extending across at least the first substrate on a surface facing the second substrate. An optical layer containing a fluid containing particles extends between the first substrate and the second substrate. For example, the optical modulator may be a conventional optical modulator, as described herein, for instance. For example, the optical modulator may be as described in connection with FIG. 3a. By applying an electric potential to the electrode system, the electric field within the optical layer is modulated, which in turn causes movement of particles within the optical layer. As a result of the new distribution of particles within the optical layer, light passing through the substrates is modulated—generally visibly so. The electrode system extending across the substrate may include one or more electrodes extending across the substrate. The electrode system may be applied to one of the first substrate and the second substrate, or to both the first substrate and the second substrate. Generally, the electrode systems are applied to the surface of the substrate facing the optical layer and may be in fluid contact, but neither is essential.

[0177] Many embodiments of optical modulators are possible. For example, particles may be moved via electrophoretic force and / or dielectrophoretic force. For example, various types of optical layers and electrode systems are possible. Some types of optical layers use an electrode system having two electrodes, one on each side, while some use three electrodes, two on one side and one on the other. Some optical layers and electrode systems use four or even more electrodes. To designate the types of optical layers, embodiments will be referred to as 2-electrode, 3-electrode, or 4-electrode.

[0178] Furthermore, fluid distribution protrusions may be of various types and may be arranged in various ways on different regions of the surface at different densities. For example, fluid distribution protrusions may be applied to a surface area that may include the entirety of at least one of the first substrate and the second substrate. The density of the fluid distribution protrusions is mm 2 There may be at least 50 per, and / or the combined area of ​​the surface zones may be at least 0.2% of the surface of the first substrate. For example, the combined area may be at least 0.3% of the surface of the first substrate. The distribution may be over a number of zones of fluid distribution protrusions of various densities and / or coverages. The distribution may be over a number of zones of fluid distribution protrusions, and the fluid distribution protrusions are of various types and have a distribution of shapes, heights and / or sizes. For example, the fluid distribution protrusions may be triangular, rectangular, cylindrical, and / or hill-shaped. For example, among the plurality of fluid distribution protrusions, the fluid distribution protrusions may have two or more different heights. For example, fluid distribution protrusions of a first height are contained in the first substrate, and fluid distribution protrusions of a second height are contained in the second substrate.

[0179] For example, the distribution of a plurality of fluid distribution protrusions can be such that at least 10%, preferably 50%, and more preferably 80% of the plurality of fluid distribution protrusions are aligned with at least one electrode. Having electrodes on the optical layer surface is advantageous because it increases the effect of the electrode system within the optical layer, but such arrangement is not essential, and, for example, the electrode system can be placed on the opposite surface.

[0180] FIGS. 5a to 5d schematically illustrate examples of embodiments of a substrate (11) for use in an embodiment of an optical modulator according to the embodiment.

[0181] In FIG. 5a, a substrate (11) is shown, and a seal (45) is arranged on the substrate (11). In an implementation in an optical modulator, the seal (45) may be applied between the substrate (11) and a possible second substrate (12). The seal (45) may seal an optical layer (17) that may extend between the substrate (11) and the possible second substrate (12). The seal (45) may be positioned at the edge of the substrate (11). The seal may simultaneously be positioned at the edge of the possible substrate (12). The optical layer (17) may contain a fluid (15) containing particles (30). By sealing the optical layer (17), the seal (15) may avoid and / or restrict fluid flow so that fluid flow does not flow out, spread, leak, and / or otherwise behave in a desired manner near the edge within the optical modulator during processing. The fluid (15) may include ink, for example, electrophoretic ink, and / or the particles (30) may include ink particles, for example, electrophoretic particles.

[0182] Due to the current physical properties of electrophoretic inks as fluids, such as low viscosity and / or low surface tension, it can be difficult to properly fill optical modulator devices, such as devices in liquid crystal display (LCD) lines, so that the fluid does not spread too quickly. Generally, ink droplets may also tend to spread too quickly near edges. By spreading too quickly near edges, the ink droplets will overflow over the sealed area. Overflowing over the sealed area can degrade the quality of the seal, and, for example, ink may eventually remain at the interface of the seal.

[0183] In FIG. 5b, a substrate (11) is shown, and a plurality of fluid distribution protrusions (18) as well as a seal (45) are arranged on the substrate (11). The fluid distribution protrusions (18) are distributed across a region (19) on the surface of the substrate (11). The region (19) is mm 2 The density of at least 10 fluid distribution protrusions (18) per may be, and / or the combined area of ​​the fluid distribution protrusions (18) may be at least 0.1% of the surface of the substrate (11).

[0184] By adding fluid distribution protrusions at a higher density on the substrate (11), several notable advantages exist during the filling process. First, when a drop of fluid, e.g., an ink drop, is placed on the substrate (11), the spreading of the drop will be limited due to reduced surface tension, which is caused by the application of fluid distribution protrusions (18) to the surface of the substrate (11) and is compared to the surface tension of the substrate (11) (e.g., a glass substrate) when the fluid distribution protrusions (18) are not applied. Additionally, when a network of fluid distribution protrusions is placed on the substrate (11), fluid flow, e.g., ink flow, can be achieved through the optical modulator device by capillary force, but in a limited manner, because the fluid flow will be limited to the height of the fluid distribution protrusions (18). Since the height of the fluid flow will be limited, it may not flow over the seal (45), and the fluid flow may be stopped once it reaches the entire sealed area. Both of these advantageous aspects can maintain good sealing quality. To achieve the effects, at least 10%, preferably 50%, and more preferably 80% of the plurality of fluid distribution protrusions (18) can be positioned on the edge around the seal (45).

[0185] The surface area (19) may include the entire substrate (11). The density of the fluid distribution protrusions (18) is mm2 There may be at least 50 per, and / or the combined area (19) may be at least 0.2% of the surface of the substrate (11), and / or the combined area (19) may be at least 0.3% of the surface of the substrate (11). The fluid distribution protrusions (18) in the area (19) may be distributed such that the fluid distribution protrusions (18) are at least 20 μm apart from each other and / or up to 1 mm apart from each other.

[0186] In FIG. 5c, a substrate (11) is shown, and a plurality of fluid distribution protrusions (18) as well as a seal (45) are arranged on the substrate (11). Here, the fluid distribution protrusions (18) are distributed across a plurality of regions (19a, 19b) on the surface of the substrate (11). An additional region (19b) of the additional surface outside the region further includes an additional plurality of fluid distribution protrusions (18), and the additional plurality of fluid distribution protrusions (18) are, within the additional region (19b), mm 2 The fluid distribution protrusions (18) may be distributed at a density of at least 10 per section. Zone (19a) may include fluid distribution protrusions (18) positioned near the edge of the sealed area around the seal (45), whereas zone (19b) may include fluid distribution protrusions closer to the middle section of the substrate (11). Zone (19a) is in mm of zone (19b). 2 Different from the density and / or coverage of the fluid distribution protrusions (18), mm 2 The fluid distribution protrusions (18) may have a density and / or coverage. The combined area of ​​the regions (19a, 19b) of the fluid distribution protrusions (18) may be at least 0.1% of the surface of the substrate (11). For example, in region (19a), the density of the fluid distribution protrusions (18) is mm 2 There may be at least 50 per, and in zone (19b), the density of the fluid distribution protrusions (18) is mm 2There may be at least 10 per. The combined area of ​​zones (19a and 19b) may be at least 0.2% of the surface of the substrate (11), and / or the combined area (19) may be at least 0.3% of the surface of the substrate (11). The fluid distribution protrusions (18) in zone (19a) may be distributed such that the fluid distribution protrusions (18) in zone (19a) are spaced at least 20 μm apart from each other and / or the fluid distribution protrusions (18) in zone (19a) are spaced up to 1 mm apart from each other.

[0187] In FIG. 5d, a substrate (11) is shown, and a plurality of fluid distribution protrusions (18) as well as a seal (45) are arranged on the substrate (11). Here, the fluid distribution protrusions (18) are distributed across a plurality of zones (19a, 19b) on the surface of the substrate (11). Zone (19a) may have a different shape from zone (19b), and / or both shapes may take more free and unusual forms, such as the described zones, which deviate from the zones (19a, 19b) of FIG. 5c, which were regular rectangular shapes. For the purpose of recognizability and / or distinction, such as in the case of logos, watermarks, and other prints that may be applied for branding purposes, for example, it may be desirable for the substrate (11) to have these shapes of zones (19a, 19b). Zone (19a) may include fluid distribution protrusions (18) located in a larger zone (e.g., a larger zone on the left side of the substrate (11)) that is different from a different larger zone (e.g., a larger zone on the right side of the substrate (11)) where the fluid distribution protrusion zone (19b) may be located. Zones (19a, 19b) may include fluid distribution protrusions (18) of various densities and / or coverages. The substrate (11) may include multiple zones (19a, 19b, 19c, etc.) of fluid distribution protrusions (18), all of which may have various densities and / or coverages. In multiple zones (19a, 19b, 19c, etc.), the fluid distribution protrusions (18) may have a distribution of sizes, heights and / or shapes. The concentration and / or density of the fluid distribution protrusions (18) may not be uniform in the zones (19a, 19b).

[0188] FIGS. 6a to 6c schematically illustrate side views of examples of embodiments of an optical modulator.

[0189] In FIG. 6a, substrates (11, 12) are shown. A seal (45) may be applied between the substrates (11, 12). Fluid distribution protrusions (18) may be applied to the substrate (11). Fluid distribution protrusions (18) may be applied to at least one of the substrates (11, 12) to affect the processing and operation of the optical modulator.

[0190] In FIG. 6b, fluid distribution protrusions (18) may be applied to both substrates. The fluid distribution protrusions (18) on the substrates (11, 12) may face each other; the fluid distribution protrusions (18) on substrate (11) may face the fluid distribution protrusions (18) on substrate (12), and vice versa. The fluid distribution protrusions may be placed on both substrates (11, 12), but may not necessarily share heights and / or positions.

[0191] In FIG. 6c, a plurality of fluid distribution protrusions (18) may include spacers (18'). The spacers (18') may be applied to at least the first substrate (11) on a surface facing the second substrate (12). The spacers (18') may maintain a cell gap between the first substrate (11) and the second substrate (12). The function of the spacers (18') will be mainly illustrated in FIG. 8b and FIG. 9b.

[0192] FIGS. 7a through 7e schematically illustrate side views of examples of embodiments of an optical modulator.

[0193] In FIG. 7a, substrates (11, 12) are shown. Here, fluid distribution protrusions (18) of two distinct heights may be applied to the substrate (11). More generally, among the plurality of fluid distribution protrusions (18), the fluid distribution protrusions (18) may have two or more different heights. The use of two distinct heights may be advantageous in the following ways. The higher of the two distinct heights may be used primarily to improve the mechanical strength and rigidity between the substrates (11, 12) and the consequently the optical modulator and / or to maintain cell gap maintenance. The lower of the two heights may be used primarily to restrict and / or avoid fluid flow. When fluid distribution protrusions (18) are placed in the electrode area, the fluid distribution protrusions may cover parts or portions of the electrode where pigments may be expected to be grouped. Then, when two separate types of heights are used in the fluid distribution protrusions (18), this can be beneficial for restricting and / or avoiding fluid flow at the expense of a smaller electrode area surface. In the case of using spacers, the lower height fluid distribution protrusions may be referred to as sub-spacers.

[0194] In FIG. 7b, fluid distribution protrusions (18) may be applied to both substrates (11, 12), and all of them may be aligned perpendicularly to each other; this may mean that fluid distribution protrusions that may be applied to substrate (11) may be aligned with corresponding fluid distribution protrusions that may be applied to substrate (12). Here, for a fluid distribution protrusion (18) applied to substrate (11), the corresponding fluid distribution protrusion (18) applied to substrate (12) may be one of the multiple fluid distribution protrusions applied to substrate (12) that may be closest in distance using a Riemannian distance in 3D space and / or a Hausdorff distance between multiple fluid distribution protrusions on substrate (11) and multiple fluid distribution protrusions on substrate (12).

[0195] In FIG. 7c, the fluid distribution protrusions (18) may be distributed across different heights, sizes, and / or shapes. First, the fluid distribution protrusions (18a, 18b, 18c) may be distributed across different sizes. Second, the fluid distribution protrusions (18d, 18e, 18f) may have different heights. The use of separate heights may be beneficial as discussed in FIG. 7a. Third, the fluid distribution protrusions (18g, 18h, 18i) may have different shapes. For example, the fluid distribution protrusion (18) may be cylindrical in shape. The fluid distribution protrusion (18g) may also be any free-form shape, for example, having a tapering head; the fluid distribution protrusion (18h) may also be triangular in shape, for example; and / or the fluid distribution protrusion (18i) may be hill-shaped, for example. Of course, combinations of sizes, heights, and / or shapes may be used, and thereby the fluid distribution protrusions may differ in both size, height, and / or shape.

[0196] In FIG. 7d, a portion of the fluid distribution protrusions (18) applied to the first substrate (11) may be aligned perpendicularly with the corresponding fluid distribution protrusions (18) on the second substrate (12). Here, with respect to the fluid distribution protrusion (18) applied to the first substrate (11), the corresponding fluid distribution protrusion applied to the second substrate (12) is the fluid distribution protrusion among the plurality of fluid distribution protrusions (18) applied to the second substrate (12) that may be closest in distance using the Riemann distance in 3D space and / or the Hausdorff distance between the plurality of fluid distribution protrusions on the substrate (11) and the plurality of fluid distribution protrusions on the substrate (12). At least 10%, preferably 50%, more preferably 80% of the plurality of fluid distribution protrusions (18) in the area of ​​the surface of the first substrate (11) may be aligned perpendicularly with respect to the corresponding fluid distribution protrusion (18) on the second substrate (12). This distance may be the vertical distance (72) between two corresponding fluid distribution protrusions (18) on the first substrate (11) and the second substrate (12).

[0197] Furthermore, the fluid distribution protrusions (18) of the first height may be included in the first substrate (11), and the fluid distribution protrusions (18) of the second height may be included in the second substrate (12). The first height and the second height may be different from each other. This means that the fluid distribution protrusions (18) in the first substrate (11) may have a separate height from the fluid distribution protrusions (18) in the second substrate (12). The sum of at least some of the heights of the corresponding fluid distribution protrusions (18) among the plurality of fluid distribution protrusions (18) in the first substrate (11) and the second substrate (12) may be equal to the width (72') of the gap between the first substrate (11) and the second substrate (12).

[0198] In FIG. 7e, a portion of the fluid distribution protrusions (18) applied to the first substrate (11) may be shifted parallel to the second substrate (12) with respect to the corresponding fluid distribution protrusions (18) on the second substrate (12). At least 10%, preferably 50%, more preferably 80% of the plurality of fluid distribution protrusions (18) in a region of the surface of the first substrate (11) may be shifted parallel to the second substrate (12) with respect to the corresponding fluid distribution protrusions (18) on the second substrate (12). Such shift (71) may include a distance equal to at least the width of the fluid distribution protrusions. The shift (71) may also include a distance equal to up to twice the maximum diameter of the cross-section of the fluid distribution protrusions (18) among the plurality of fluid distribution protrusions (18). The shift (71) may include, for example, a distance of at least 0.5 μm. These shifts (71) can ensure better processability of the optical modulator device, because they can account for alignment errors that may occur during the production process of the device, for example, a one drop fill (ODF) device.

[0199] In an embodiment, the shifts from the fluid distribution protrusions of the substrate (11) to the fluid distribution protrusions of the substrate (12) are not the same for all fluid distribution protrusions. For each fluid distribution protrusion or group of fluid distribution protrusions, the shift may be made in any direction parallel to the substrate (11 or 12). When considering all or part of the population of fluid distribution protrusions on the substrate (11 or 12), multiple shift directions and distances may exist. This helps to compensate for production misalignment between the substrate (11) and the substrate (12). By shifting the fluid distribution protrusions of the substrate (11 or 12) by various directions and distances, sufficient physical contact between the fluid distribution protrusions of the substrate (11 and 12) is made more likely, even if not guaranteed, during the alignment process in production and for the final optical modulator. The range of shift distance distributions of the fluid distribution protrusions includes from a state without shift to a maximum distance corresponding to the alignment tolerance of the alignment production machine.

[0200] FIG. 7f schematically illustrates examples of embodiments of fluid distribution protrusions. The fluid distribution protrusion (18j) may be cylindrical in shape. The fluid distribution protrusion (18k) may be triangular in shape.

[0201] The diameter (74, 74') of the fluid distribution protrusion may be the maximum distance between all possible points across the cross-sections of the shape of the fluid distribution protrusion. In the case of a cylindrical shape of the fluid distribution protrusion (18j), this is the diameter (74) of the circle forming the cross-sectional surfaces. In the case of a triangular shape of the fluid distribution protrusion (18k), this is the diameter (74') of the square forming the cross-sectional surface at the bottom, which is the length of the diagonal side formed by a line crossing the center of the square by connecting the corners placed on top. The diameter (74, 74') of the fluid distribution protrusion (18) may generally be 1 μm. The height (73, 73') of the fluid distribution protrusion (18) may generally be smaller than the thickness of the optical modulator, which may generally be 10 μm. The fluid distribution protrusions (18) may have a cross-sectional diameter of at least 1 μm. The fluid distribution protrusions (18) can have a height of at least 6 μm.

[0202] FIG. 8a schematically illustrates an example of an ink droplet (81) falling onto a substrate (11) without spacers, and FIG. 8c illustrates the result of the ink droplet (81) spreading after falling onto the substrate (11) without spacers.

[0203] Due to the current physical properties of electrophoretic inks as fluids, such as low viscosity and / or low surface tension, it may be difficult to properly charge optical modulator devices, such as devices within a liquid crystal display (LCD) line, so that the fluid does not spread too quickly. Generally, ink droplets (81) may tend to spread too quickly on the substrate (11) and also near the edges. By spreading too quickly near the edges, the ink droplets will overflow over the sealed area and overflow over the seal (45). By overflowing over the sealed area, the quality of the seal may be degraded, and, for example, ink will eventually remain at the interface of the seal (45).

[0204] FIG. 8b schematically illustrates an example of an ink droplet (81) falling onto a substrate (11) having spacers (18'), and FIG. 8d illustrates the result of the ink droplet (81) spreading after falling onto the substrate (11) having spacers (18'). By adding spacers (18') onto the substrate (11), this can be advantageous in the filling process. When the ink droplet (81) is placed on the substrate (11), the spreading of the ink droplet (81) will be limited due to reduced surface tension, which is caused by the application of spacers (18') to the surface of the substrate (11), compared to the surface tension of the substrate (11) in the case of FIG. 8a and FIG. 8c where spacers (18') are not applied. Now, the flow of the ink particles (81) can be limited, because the flow may not rise above the height of the spacers (18'). Since the height of the fluid flow can be limited, it may not flow over the seal (45), and the flow may be stopped once it reaches the entire sealed area. These advantageous aspects can maintain good seal quality.

[0205] FIG. 9a schematically illustrates an example of an embodiment of an optical modulator without spacers. The optical modulator may comprise substrates (11, 12) and a fluid (15) containing particles (30) that can flow through an optical layer extending between the substrates (11, 12). The optical modulator may be oriented vertically, for example, for use in a window. Process conditions during the manufacturing and / or use process of the optical modulator may be such that the stability of the optical modulator may not be maintained during the process. In particular, the processing of one drop filling (ODF) that may be used to manufacture electrophoretic optical modulators, such as displays for liquid crystal displays (LCDs), may be susceptible to bulging effects, which means that the mechanical robustness of the optical modulator may be low, and even when the process conditions under which the manufacturing and / or use process of the optical modulator may change, there may be a possibility that the substrates (11, 12) may break, and / or shift and / or tilt in an unwanted manner during the processes.

[0206] FIG. 9b schematically illustrates an example of an embodiment of an optical modulator comprising substrates (11, 12) having spacers (18'). Now, fluid flow of a fluid (15) containing particles (30) can be achieved through the optical modulator device by capillary force, and a distribution involving spacers (18') of relatively high density compared to the prior art can improve the aforementioned process conditions during the manufacturing and / or use process of the optical modulator, as the distribution can contribute to the stability of the optical modulator during the process. In particular, processing of one-drop filling (ODF) that can be used to manufacture displays for electrophoretic optical modulators, such as liquid crystal displays (LCDs), can be supported. Furthermore, a distribution involving a relatively high density of spacers (18') compared to conventional technology can contribute to the mechanical robustness of the optical modulator, as the substrates (11, 12) may be less likely to break, shift, and / or tilt in an unwanted manner when the process conditions under which the manufacturing and / or use process of the optical modulator can take place may change. In particular, by increasing capillary force, a distribution involving a relatively high density of spacers (18') compared to conventional technology can limit the bulging effect, which may occur particularly in the vertical orientation of the substrates (11, 12), for example, glass substrates that can be implemented in a window setting. As the spacers (18') maintain the cell gap between the substrates (11, 12) during the lifetime of the optical modulator, thereby increasing the lifetime and reliability of the optical modulator, the bulging effect can also be limited, which contributes to the mechanical stability and robustness of the substrates (11, 12) and the optical modulator accordingly.

[0207] FIGS. 10a and 10b schematically illustrate examples of embodiments of a substrate (11) to which electrodes (13a, 13b), etc., as well as fluid distribution protrusions (18a, 18b), etc., can be applied.

[0208] In FIG. 10b, a substrate (11) to which electrodes (13a, 13b) and the like, as well as fluid distribution protrusions (18a, 18b) and the like can be applied is shown. Here, there may not be a clear distribution of the plurality of fluid distribution protrusions such that at least 10%, preferably 50%, more preferably 80% of the plurality of fluid distribution protrusions can be aligned with the electrodes (13a, 13b) and the like.

[0209] In FIG. 10a, the distribution of a plurality of fluid distribution protrusions can be such that at least 10%, preferably 50%, and more preferably 80% of the plurality of fluid distribution protrusions are aligned with the electrodes (13a, 13b). In this distribution, the area where the fluid distribution protrusions can be distributed may overlap with the area where at least one electrode can be distributed, and the fluid distribution protrusions may be obscured by at least one electrode. At least one electrode may be wholly or partially non-transparent. Then, this distribution of fluid distribution protrusions can wholly or partially avoid any possible negative effect, such as increased diffraction effects, that the fluid distribution protrusions and / or their distribution might otherwise have on the optical properties of the optical modulator device, and / or may be beneficial to the contrast properties of the optical modulator device. A distribution of multiple fluid distribution protrusions such that at least 10%, preferably 50%, and more preferably 80% of the multiple fluid distribution protrusions are aligned with at least one electrode can be beneficial to the optical performance of the optical modulator.

[0210] FIG. 11 schematically illustrates an example of a method (900) for modulating light according to an embodiment. The method (900) may include the step of applying an electric potential to at least one electrode in step (910), at least one electrode may be applied to at least one of two opposing substrates, and at least one of the two opposing substrates may be according to an embodiment. Applying an electric potential may cause modulation of an electric field within an optical layer, the optical layer may extend between two opposing substrates, the optical layer may include a fluid containing particles, and may provide electrophoretic and / or dielectrophoretic movement of particles within the optical layer, and this movement may cause modulation of light passing through the optical layer.

[0211] FIG. 12 illustrates an example of a method (1000) for manufacturing an optical modulator according to an embodiment. The method (1000) includes the step of providing a first substrate according to an embodiment in step (1010);

[0212] Step (1020) of applying a seal along the edge of the first substrate;

[0213] Step (1030) of providing a fluid containing particles on a first substrate within a sealed area;

[0214] and may include the step of providing a second substrate facing the first substrate in step (1040). In this way, an optical layer is formed between the first substrate and the second substrate, and the optical layer may be sealed by a seal. In the described manufacturing method, inkjet printer technology may be used. The method may be performed on a one-drop fill (ODF) machine.

[0215] It should be noted that the foregoing embodiments are illustrative rather than limiting of the subject matter of the claims disclosed herein, and that those skilled in the art may design many alternative embodiments.

[0216] In the claims, any reference numerals placed between parentheses should not be interpreted as limiting the claims. The use of the verb 'comprise' and its conjugations does not exclude the existence of elements or steps other than those described in the claims. The articles 'a' or 'an' preceding an element do not exclude the existence of multiple such elements. Expressions such as "at least one of" preceding a list of elements indicate the selection of all or any subset of elements from the list. For example, the expression "at least one of A, B, and C" should be understood to include only A, only B, only C, both A and B, both A and C, both B and C, or all of A, B, and C. The subject matter of the claims disclosed herein may be implemented by hardware comprising several distinct elements and by a suitably programmed computer. In device claims enumerating several parts, several of these parts may be implemented by a single identical hardware item. The mere fact that certain means are described in mutually distinct dependent claims does not indicate that a combination of these means cannot be used advantageously.

[0217] References within parentheses in the claims refer to reference numerals in the drawings of exemplary embodiments or formulas of embodiments, thereby enhancing the understanding of the claims. These references should not be interpreted as limiting the claims.

Claims

Claim 1 As an optical modulator (10), a first substrate (11), a second substrate (12) arranged opposite to the first substrate (11), at least one electrode (13, 13a, 13b, 14, 14a, 14b) applied to at least the first substrate (11) on a surface facing the second substrate (12), and an optical layer (17) extending between the first substrate (11) and the second substrate (12) — the optical layer (17) comprises a fluid (15) containing particles (30), and the optical modulator (10) is configured to apply an electric potential to the at least one electrode (13, 13a, 13b, 14, 14a, 14b), the application of said electric potential causes modulation of an electric field within the optical layer (17), and said modulation of the electric field of the particles (30) within the optical layer (17). Providing electrophoretic and / or dielectrophoretic movement to cause modulation of light passing through the optical layer (17) — and comprising a plurality of fluid distribution protrusions (18, 18a, 18b) for controlling the flow of the fluid (15) within the optical layer (17), wherein the plurality of fluid distribution protrusions (18, 18a, 18b) are distributed across a region (19) on the surface of at least one of the first substrate and the second substrate, and the region (19) is mm 2 An optical modulator (10) having a density of at least 10 fluid distribution protrusions (18, 18a, 18b) and / or the combined area of ​​said fluid distribution protrusions (18, 18a, 18b) being at least 0.1% of the surface of said first substrate (11). Claim 2 In claim 1, the surface area (19) comprises the entirety of at least one of the first substrate (11) and the second substrate (12), an optical modulator (10). Claim 3 In claim 1 or 2, the density of the fluid distribution protrusions (18, 18a, 18b) is mm 2 An optical modulator (10) having at least 50, and / or the combined area (19) is at least 0.2% of the surface of the first substrate (11), and / or the combined area (19) is at least 0.3% of the surface of the first substrate (11). Claim 4 In any one of claims 1 to 3, the fluid distribution protrusions (18, 18a, 18b) in the zone (19) are distributed such that they are spaced at least 20 μm apart from each other and / or spaced up to 1 mm apart from each other, in an optical modulator (10). Claim 5 An optical modulator (10) comprising a plurality of zones (19, 19a, 19b) of fluid distribution protrusions (18, 18a, 18b) of various densities and / or coverages, in any one of claims 1 to 4. Claim 6 An optical modulator (10) according to any one of claims 1 to 5, wherein the fluid distribution protrusions (18, 18a, 18b) comprise one or more zones (19, 19a, 19b) having a distribution of sizes, heights and / or shapes. Claim 7 An optical modulator (10) according to any one of claims 1 to 6, wherein at least 10%, preferably 50%, more preferably 80% of the plurality of fluid distribution protrusions (18, 18a, 18b) are aligned with at least one electrode (13, 13a, 13b, 14, 14a, 14b). Claim 8 An optical modulator (10) according to any one of claims 1 to 7, further comprising a seal (45) applied between the first substrate (11) and the second substrate (12) to seal the optical layer (17), wherein the seal (45) is positioned at the edge of at least one of the substrates (11, 12). Claim 9 In claim 8, an optical modulator (10) wherein at least 10%, preferably 50%, more preferably 80% of the plurality of fluid distribution protrusions (18, 18a, 18b) are positioned on the edge around the seal (45). Claim 10 An optical modulator (10) according to any one of claims 1 to 9, wherein at least 10%, preferably 50%, more preferably 80% of the plurality of fluid distribution protrusions (18, 18a, 18b) in the region (19) of the surface of the first substrate (11) are aligned perpendicularly with the corresponding fluid distribution protrusions (18, 18a, 18b) in the second substrate (12). Claim 11 An optical modulator (10) according to any one of claims 1 to 9, wherein at least 10%, preferably 50%, more preferably 80% of the plurality of fluid distribution protrusions (18, 18a, 18b) in the region (19) of the surface of the first substrate (11) are shifted parallel to the second substrate (12) with respect to the corresponding fluid distribution protrusions (18, 18a, 18b) in the second substrate (12). Claim 12 In claim 11, an optical modulator (10) in which the directions and distances of shifts parallel to the substrate are not the same for all fluid distribution protrusions. Claim 13 In claim 11, an optical modulator (10) in which the directions and distances of the shifts are randomly distributed across the substrate. Claim 14 An optical modulator (10) according to any one of claims 11 to 13, wherein the shift includes a distance of at least one-tenth of the width of the spacer. Claim 15 An optical modulator (10) according to any one of claims 11 to 14, wherein the shift comprises a distance of up to twice the maximum diameter of the cross-section of the fluid distribution protrusions (18, 18a, 18b) among the plurality of fluid distribution protrusions (18, 18a, 18b). Claim 16 In any one of claims 11 to 15, the optical modulator (10) comprises a shift of at least 0.5 μm. Claim 17 An optical modulator (10), wherein, in any one of claims 1 to 16, the fluid distribution protrusions (18, 18a, 18b) among the plurality of fluid distribution protrusions (18, 18a, 18b) have a cross-sectional diameter of at least 1 μm, and / or the fluid distribution protrusions (18, 18a, 18b) among the plurality of fluid distribution protrusions (18, 18a, 18b) have a height of at least 6 μm, and / or the sum of at least some of the heights of the corresponding fluid distribution protrusions (18, 18a, 18b) among the plurality of fluid distribution protrusions (18, 18a, 18b) on the first substrate (11) and the second substrate (12) is equal to the width of the gap between the first substrate (11) and the second substrate (12). Claim 18 An optical modulator (10) according to any one of claims 1 to 17, wherein the fluid distribution protrusions (18, 18a, 18b) among the plurality of fluid distribution protrusions (18, 18a, 18b) are triangular in shape, rectangular in shape, cylindrical in shape and / or hill-shaped. Claim 19 An optical modulator (10) according to any one of claims 1 to 18, wherein the fluid distribution protrusions (18, 18a, 18b) among the plurality of fluid distribution protrusions (18, 18a, 18b) have two or more different heights. Claim 20 In claim 19, the first height fluid distribution protrusions (18, 18a, 18b) are included in the first substrate (11), and the second height fluid distribution protrusions (18, 18a, 18b) are included in the second substrate (12), an optical modulator (10). Claim 21 In any one of claims 1 to 20, the plurality of fluid distribution protrusions (18, 18a, 18b) include spacers, said spacers applied to at least the first substrate (11) on a surface facing the second substrate (12), an optical modulator (10). Claim 22 In any one of claims 1 to 21, the surface region (19) of at least one of the first substrate (11) and the second substrate (12) is hydrophilic and / or 30-50 mJ / mm 2 Optical modulator (10) having surface energy between them. Claim 23 In any one of claims 1 to 22, the fluid (15) comprises ink, and / or the particles (30) comprise ink particles, a light modulator (10). Claim 24 A substrate (11) for use in an optical modulator (10), comprising at least one electrode (13, 13a, 13b, 14, 14a, 14b) applied to the substrate (11), and a plurality of fluid distribution protrusions (18, 18a, 18b), wherein the plurality of fluid distribution protrusions (18, 18a, 18b) are formed within a region (19) of the surface of the substrate (11) of mm 2 A substrate (11) distributed across the zone (19) at a density of at least 50 fluid distribution protrusions (18, 18a, 18b). Claim 25 A method (900) for modulating light comprises the step (910) of applying an electric potential to at least one electrode (13, 13a, 13b, 14, 14a, 14b) applied to at least one of two opposing substrates (11, 12), wherein the application of the electric potential causes modulation of an electric field within an optical layer (17) — the optical layer (17) extends between the two opposing substrates (11, 12) and comprises a fluid (15) containing particles (30) — the modulation of the electric field provides electrophoretic and / or dielectrophoretic movement of the particles (30) within the optical layer (17), thereby causing modulation of light passing through the optical layer (17), and wherein at least one of the two opposing substrates (11, 12) is the same as in claim 24. Claim 26 A method (1000) for manufacturing an optical modulator (10), comprising the steps of: providing a first substrate (11) as in claim 22 (1010); applying a seal (45) along the edge of the first substrate (11) (1020); providing a fluid (15) containing particles (30) on the first substrate (11) within a sealed area (1030); and providing a second substrate (12) facing the first substrate (11) (1040) — thereby forming an optical layer (17) between the first substrate (11) and the second substrate (12), wherein the optical layer (17) is sealed by the seal (45).

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