Substrate having electrodes equipped with an optical modulator and aperture

Abstract

Several embodiments relate to an optical modulator having a first substrate and a second substrate, the first and second substrates arranged so that their inner surfaces face each other, the first substrate being transparent, and at least one driving electrode applied to the inside of the first substrate, the driving electrode extending in a pattern across the inside of the first substrate, the driving electrode having multiple apertures extending through the electrode, thus allowing incident light to pass through the first substrate and the driving electrode into the optical layer, or vice versa.

Description

Technical Field

[0001] The presently disclosed subject matter relates to optical modulators, substrates, and methods for manufacturing substrates.

Background Art

[0002] Known optical modulators are disclosed in WO2022023180, which is hereby incorporated by reference herein. Known optical modulators include a transparent or reflective substrate. A plurality of electrodes are applied to the substrate in a pattern across the substrate. A controller may apply a potential to the electrodes to obtain an electromagnetic field between the electrodes that provides electrophoretic movement of particles towards or away from the electrodes.

Prior Art Documents

Patent Documents

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Patent Document 10

Summary of the Invention

[0004] Having an improved optical modulator would be advantageous. [Means for solving the problem]

[0005] In embodiments of the optical modulator, at least one driving electrode is applied to the inside of a transparent substrate, and the driving electrode extends in a pattern traversing the inside of the substrate. One or more driving electrodes have multiple apertures extending through the electrode, thus allowing incident radiation to pass through the first substrate and driving electrode into the optical layer, or vice versa.

[0006] The incident radiation may include infrared radiation and / or visible light. If an aperture is positioned to allow infrared radiation to pass through, the electrode will be more permeable to infrared radiation.

[0007] The optical modulator comprises at least two substrates arranged opposite each other. At least one drive electrode may be applied to one or both substrates, and each substrate may be supplied with an aperture. Both substrates may be transparent.

[0008] An optical layer containing a fluid with particles is placed between a first substrate and a second substrate. The controller is configured to apply a potential to at least one driving electrode to obtain an electromagnetic field that provides motion for particles toward or away from the driving electrode, thereby causing modulation of the optical properties of the optical modulator.

[0009] Apertures offer various benefits to optical modulators. Electrodes with multiple apertures applied to them are less visible in optical modulators. This is particularly important in various applications. For example, in dynamic glazing, also known as smart glass, as exemplified by certain systems, visible electrodes can be distracting. For instance, in automobiles, reducing the visibility of electrodes contributes to safety.

[0010] The electric field tends to be most effective near the edge of the electrode, and by applying an aperture, the effect of the electrode increases. As a result, the transition between different optical states of the optical modulator is faster and more uniform.

[0011] An aperture allows more radiation to enter the optical modulator, thus reducing the amount of radiation blocked by the modulator. For example, in dynamic glazing applications, the amount of ambient light, such as sunlight, that can enter through the dynamic glazing increases, even in the most transparent state of the optical modulator. As a result, there is less need for artificial light. For example, in a greenhouse, the amount of infrared radiation transmitted into the greenhouse may increase by using an aperture adapted for infrared radiation.

[0012] Apertures can influence light scattering and therefore contribute to optical effects such as diffraction. Having apertures allows for greater freedom in optical modulator design to reduce diffraction. For example, the distribution, shape, orientation, and / or size of apertures may be varied, for instance, randomized, to reduce diffraction.

[0013] In the embodiment, the multiple apertures have multiple different diameters. In the embodiment, the distribution of the multiple apertures is randomized over at least a portion of at least one electrode.

[0014] In an embodiment, the optical modulator is an electrophoretic optical modulator. The particles are electrically charged or can be charged, and the controller is configured to apply a potential to one or more drive electrodes to obtain an electromagnetic field that provides the electrophoretic motion of the particles toward or away from the drive electrodes, thereby causing modulation of the optical properties of the optical modulator.

[0015] Further embodiments include a substrate for use in an optical modulator and a method for manufacturing the substrate.

[0016] Further details, aspects, and embodiments are described by way of example only, with reference to the drawings. The elements of the figures are shown for simplicity and clarity and are not necessarily drawn to scale. In the figures, elements corresponding to elements already described may have the same reference numerals.

Brief Description of the Drawings

[0017] [Figure 1a] It is a diagram schematically showing an example of an embodiment of a building block. [[ID=I3]] [Figure 1b] It is a diagram schematically showing an example of an embodiment of a substrate. [Figure 1c] It is a diagram schematically showing an example of an embodiment of a substrate. [Figure 1d] It is a diagram schematically showing an example of an embodiment of a substrate. [Figure 1e] It is a diagram schematically showing an example of an embodiment of a substrate. [Figure 1f] It is a diagram schematically showing an example of an embodiment of a substrate. [Figure 2a] It is a diagram schematically showing an example of an embodiment of a substrate. [Figure 2b] It is a diagram schematically showing an example of an embodiment of a substrate. [Figure 2c] It is a diagram schematically showing an example of an embodiment of a substrate. [[ID=3t]] [Figure 2d] It is a diagram schematically showing an example of an embodiment of a substrate. [Figure 2e] It is a diagram schematically showing an example of an embodiment of a substrate. [Figure 2f] It is a diagram schematically showing an example of an embodiment of a substrate. [Figure 3a] It is a diagram schematically showing an example of an embodiment of an optical modulator. [Figure 3b] j It is a diagram schematically showing an example of an embodiment of an optical modulator. [Figure 3c] It is a diagram schematically showing an example of an embodiment of a vehicle. [Figure 4a] It is a diagram schematically showing an embodiment of an optical modulator. [Figure 4b] This is a schematic diagram showing an embodiment of an optical modulator. [Figure 4c] This is a schematic diagram showing an embodiment of an optical modulator. [Figure 5a.1] This figure schematically shows an example of a substrate embodiment. [Figure 5a.2] This figure schematically shows an example of an aperture embodiment. [Figure 5b] This figure schematically illustrates an example of a tessellation embodiment. [Figure 5c] This is a schematic diagram showing an example of an electrode embodiment. [Figure 5d] This is a schematic diagram showing an example of an electrode embodiment. [Figure 5e] This figure schematically shows an example of an electrode embodiment. [Figure 5f.1] This is a schematic diagram showing an example of an electrode embodiment. [Figure 5f.2] This diagram schematically shows an example of a shift mechanism. [Figure 5g.1] This figure schematically shows an example of an electrode embodiment. [Figure 5g.2] This figure schematically shows an example of an aperture embodiment. [Figure 5h] This figure schematically shows an example of an electrode embodiment. [Figure 6a] This is a schematic diagram showing an example of an electrode embodiment. [Figure 6b] This figure schematically shows an example of an electrode embodiment. [Figure 6c] This figure schematically shows an example of an electrode embodiment. [Figure 7a] This is a schematic diagram showing an example of an electrode embodiment. [Figure 7b] This is a schematic diagram showing an example of an electrode embodiment. [Figure 8a] This figure schematically illustrates a computer-readable medium having a writable portion containing a computer program, according to an embodiment. [Figure 8b] This figure schematically illustrates a representation of a processor system according to an embodiment. [Modes for carrying out the invention]

[0018] List of reference symbols The following list of references and abbreviations is provided to facilitate the interpretation of the drawings and shall not be construed as limiting the claims.

[0019] 10 Optical modulator 11. First substrate 12 Second substrate 13, 13a, 13b electrode 14, 14a, 14b electrode 15 Fluid 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 circuit board 111-114 Main line 121-124 Main Line 131-134 Interdigitated electrodes 140 Building Blocks 141-144 Building Blocks 110, 120 drive bus 110', 120' drive bus 119, 129 connection zones 191, 192 direction 603-604 circuit board 611-622 Building Blocks 651-662 Building Blocks 500 circuit boards 501, 502 electrode edge 503 Electrode 504 vertices 505 line width 509 Details 510 Aperture 511-514 Aperture 520 serrated teeth 521 Serrated electrode edge 522 Original Aperture 523 Shifted Aperture 531 Aperture 532 Exclusion Zone 540 electrode 541-543 direction 544 Aperture 601 Electrode Edge 650 Aperture 602 Aperture 651 Points on the Aperture Edge 652-653 distance 654 Points on the electrode edge 655 distance 656 serrated teeth 657 distance 711 Low density region 712 High density area 1000, 1001 Computer-readable media 1010 Writable portion 1020 Computer Programs 1110 Integrated circuits (multiple possible) 1120 Processing Units 1122 memory 1124 Dedicated Integrated Circuit 1126 Communication elements 1130 Interconnect 1140 Processor System

[0020] While the subject matter currently disclosed can take many different forms, one or more specific embodiments are shown in the drawings and described herein in detail, with the understanding that this disclosure is intended to be illustrative of the principles of the subject matter currently disclosed and is not intended to limit the disclosure to any particular embodiment shown and described.

[0021] In the following, for the sake of understanding, the elements of the embodiments are described in their operating state. However, it is clear that each element is configured to perform the function described as being performed by that element. Furthermore, the subject matter now disclosed is not limited to the embodiments alone, but also includes all other combinations of features described herein or cited in dependent claims that differ from each other.

[0022] For example, a substrate for use in optical modulators, particularly in dynamic glazing, is disclosed. The substrate is transparent, and at least one driving electrode is applied to the surface of the substrate, the driving electrode extending in a pattern across the surface of the first substrate. Interestingly, when the optical modulator is in use, it is advantageous that the driving electrode has multiple apertures extending through the electrode, thus allowing incident radiation to pass through the first substrate and the driving electrode, or vice versa. For example, the radiation may be visible light. This has at least some effect. Because some light will pass through the apertures, the electrode is less conspicuous, for example, difficult to see easily. Another effect of perforated electrodes, i.e., electrodes with apertures, is increased effectiveness of the electric field. For example, when moving particles to modulate the optical properties of an optical modulator, it has been observed that the electric field is most effective near the edges of the electrode. Perforating or serrating the electrode increases the effectiveness of the substrate in the optical modulator.

[0023] Many types of optical modulators exist that use such substrates. Some known optical modulators are based on the principle of electrophoresis. For example, the substrate may have multiple interdigitated drive electrodes applied to it, for example, two electrodes, each of which is arranged in a pattern across the substrate, and the multiple interdigitated drive electrodes are arranged alternately relative to each other on the substrate. Having multiple interdigitated electrodes allows for local control of the electric field and enables control of particle electrophoresis.

[0024] Electrophoretic optical modulators are described more extensively herein and are used as motivational examples. In embodiments, the optical modulator comprises a first substrate and a second substrate. At least one of the first and second substrates may conform to embodiments having perforated electrodes. For example, the first and second substrates may be arranged so that their inner surfaces face each other. Using substrates according to embodiments has the effect of reducing optical interference, for example. An optical layer is placed between the first and second substrates. A driving electrode is placed to modulate the electric field in the optical layer. The optical layer contains a fluid containing particles, which are electrically charged or can be charged. The particles may move under the control of the electric field. For example, a controller may be configured to apply a potential to the driving electrode to obtain an electromagnetic field at the driving electrode, resulting in the electrophoretic motion of particles toward or from one of the at least one driving electrodes, causing modulation of the optical properties of the optical modulator.

[0025] Below, several known optical modulators are reviewed, and some of the options in terms of technique and electrodes are shown. These known substrates can be advantageously modified by perforating electrodes. These examples also show optical modulators with varying numbers of electrodes on the substrate.

[0026] International patent applications WO2011012499A1 (included herein by reference) and WO2011131689 (included herein by reference) disclose electrophoretic display devices, for example, optical modulators in the form of e-ink displays. The pixels of the display comprise an accumulation electrode and a field electrode, the accumulation electrode being located in a storage area for accumulating charged particles, away from the aperture area, and the field electrode occupying the field electrode area being at least a portion of the aperture area of ​​the pixel, and the charged particles being movable between the accumulation electrode and the field electrode. In embodiments, the two electrodes are applied to a single substrate. The accumulation electrode and / or the field electrode may be perforated.

[0027] U.S. Patent No. 1,0921678, included herein by reference and having the title “Electrophoretic device,” describes an electrophoretic device having only one patterned electrode on one of two substrates. For example, one substrate having an electrode according to U.S. Patent No. 1,0921678 can be replaced with a substrate according to an embodiment having one single electrode. For example, the embodiment comprises a first transparent substrate having a field electrode, and a second substrate facing the first substrate having a storage electrode. The first and second substrates enclose pixels with fluid and particles. During use, the electromagnetic fields applied to the field electrode and the storage electrode provide the movement of particles from the field electrode and the storage electrode, and vice versa. The field electrode and / or storage electrode may be perforated.

[0028] U.S. Patent 8054535B2 (included herein by reference) and U.S. Patent 8384658B2 (included herein by reference) provide examples of alternative electrophoretic photomodulators having one of two substrates with two patterned electrodes.

[0029] Patterned electrodes are also used in dielectrophoretic photomodulators. For example, U.S. Patent Application No. 2005185104A1 (included herein by reference) and U.S. Patent Publication No. 20180239211A1 (included herein by reference) illustrate dielectrophoretic photomodulators having a substrate with patterned electrodes. Any of these electrophoretic photomodulators or dielectrophoretic photomodulators may be adapted, according to embodiments, by perforating electrodes on a substrate.

[0030] The paper “Reversible Metal Electrodeposition Devices: An Emerging Approach to Effective Light Modulation and Thermal Management,” included by reference, also shows a substrate on which patterned electrodes are applied. The patterned electrodes may be advantageously configured according to the embodiment.

[0031] The substrate embodiment may be used in electrochromic devices (ECDs). Electrochromic devices (ECDs) continuously but reversibly control optical properties such as optical transmission, absorption, reflection, and / or emittance by applying voltage (electrochromism). This property allows electrochromic devices to be used for applications such as smart glass, electrochromic mirrors, and electrochromic display devices.

[0032] Electrochromic devices are described, for example, in the paper "Silver grid electrodes for faster switching ITO-free electrochromic devices" by Antonio California et al., which is included herein by reference. That paper describes the preparation of electrochromic devices, in this case, ITO-free electrochromic devices.

[0033] Electrochromic devices use electrically conductive electrodes applied to a substrate. The cited paper uses a silver grid made with silver ink as the electrically conductive electrode. Electrochromic devices may contain electrochromic materials. The cited paper uses poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). In an electrochromic device, at least one driving electrode, such as an electrically conductive electrode, is applied to the substrate. The driving electrode is arranged in a pattern across the substrate. The cited paper discloses two different grid patterns, regular hive and regular ladder designs. See Table 1 and Figure 3 of the cited paper.

[0034] In the cited paper, electrodes may be applied to a substrate by screen printing polyethylene terephthalate (PET) onto the substrate. The electrodes are typically electrically conductive materials, such as metals or metal oxides. In the cited paper, silver ink was used to screen print a grid onto the PET using a RokuPrint RP 2.2 instrument and a 180-wired mesh. The samples were dried in a furnace at 130°C for 15 minutes. One or two layers of PEDOT:PSS SV3 were subsequently screen printed on top of these silver grids. Light passes through the electrodes, which in this case are applied in a fixed pattern, and the electrodes, for example, the pattern may be perforated according to the embodiment.

[0035] For example, the metal grid used in the cited paper may be replaced by a driving electrode applied to a substrate, and the driving electrode is perforated according to the embodiment.

[0036] Another example of an electrochromic device is given in U.S. Patent No. 5,161,048, titled “Electrochromic window with metal grid counter electrode and acidic polyelectrolyte,” which is incorporated herein by reference. For example, an electrochromic device may comprise a transparent electrochromic film and an ion-conducting layer disposed between pairs of electrodes. A metal grid electrode is provided for the electrode. Figure 1 of the patent shows a metal grid according to the cited patent. To form a counter electrode, the metal grid is disposed adjacent to a second glass substrate.

[0037] For example, in an embodiment of an electrochromic device, the electrochromic device may comprise 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. The patterned conductive electrode may vary according to the embodiment.

[0038] The substrates according to the embodiments may be advantageously applied in several other technologies. For example, the optical modulator may be a dielectrophoretic optical modulator, as shown, for example, in U.S. Patent Application Publication No. 20050185104A1, which is included herein by reference. Substrates like those in the embodiments may also be used in other electrowetting and OLED applications.

[0039] In OLEDs and electrowetting, electrodes are required on only one of several substrates. The substrate having the electrodes may vary according to the embodiment.

[0040] In applications such as glazing optical modulators, both substrates are typically transparent. In other applications, such as televisions and e-readers, only one substrate may be transparent.

[0041] In the embodiment, the driving electrode applied to the substrate comprises a plurality of apertures extending through the electrode, thus allowing incident radiation to pass through the substrate and the driving electrode into the optical layer, or vice versa. In Figures 1a-4c, the apertures are not visible in the figures.

[0042] Figure 1b schematically shows an example of a substrate embodiment. The substrate is particularly useful for use in optical modulators of the type described herein. Multiple interlocking drive electrodes are applied to the substrate across it. Two electrodes are shown in Figure 1b.

[0043] An exemplary use of substrate motivation is in an electrophoretic optical modulator. Typically, an electrophoretic optical modulator comprises at least two substrates, each having at least two driving electrodes; however, although not required, an electrophoretic optical modulator may also comprise, for example, a single substrate having two electrodes and a counter substrate having one electrode. In either case, preferably, at least one of the substrates in the optical modulator follows the embodiment.

[0044] An embodiment of the optical modulator comprises a first substrate and a second substrate according to the embodiment. The first and second substrates are arranged so that their inner surfaces face each other. At least one drive electrode is applied to the inside of the first substrate. An optical layer is placed between the first and second substrates. A controller is configured to apply a potential to at least one drive electrode that causes modulation of the optical properties of the optical modulator. One or both of the first and second substrates are transparent and / or translucent.

[0045] There are many different types of optical modulators that use at least one driving electrode applied to a substrate. When radiation passes through a substrate, some of the radiation may be blocked by the electrode, and using an aperture can reduce this reduction. For example, in the case of visible light, this results in clearer and more transparent glass. Optical layers and controllers may be arranged to modulate optical properties using potential-dependent effects on the driving electrode; examples include dielectrophoretic and electrophoretic effects. For example, optical modulation may involve the modulation of particles placed within the optical layer. The number of driving electrodes may range from one on a single substrate to multiple driving electrodes on one or both substrates.

[0046] The optical layer placed between the first and second substrates may, for example, contain particles suspended in a fluid. The controller may be configured to apply a potential to the driving electrode, causing the particles to move and thus modulating the optical properties of the optical modulator.

[0047] In embodiments, the particles include electrically charged or chargeable particles, and the controller is configured to apply a potential to the driving electrodes to obtain an electromagnetic field that causes the electrophoretic motion of the particles. In embodiments, the electromagnetic field is configured between at least two driving electrodes located on the same substrate or on different substrates.

[0048] In the embodiment, the particles include dielectric particles, and the controller is configured to apply a potential to the driving electrode to apply an electric field gradient to the particles, thereby enabling the particles to move under the action of dielectrophoretic force.

[0049] The controller may apply an electrical signal to one or more of the drive electrodes. Embodiments controlling electrophoretic force may use a signal that includes DC and / or AC signals. Embodiments controlling electrophoretic force may use a signal that includes DC and / or AC signals.

[0050] Figure 1b shows two drive electrodes on the same surface. The two drive electrodes are shown in Figure 1b with two different dashed line styles. For example, there may be three or more electrodes on the same side of the substrate to facilitate finer control of the voltage difference across the substrate. The drive electrodes are applied to the same side of the substrate. Applying electrodes to a substrate may be done by lithography, for example, using a mask that represents the electrode pattern. Electrodes may also be applied by embedding them in the substrate.

[0051] The drive electrodes are electrically connected and, for example, have the same potential everywhere. The drive electrodes may include a drive bus and a main line. At a minimum, the main line mates with the main lines of further drive electrodes. Typically, the drive electrodes extend in a substantially straight line across the substrate, while the main lines are intricate.

[0052] In an embodiment, each of the two substrates of the optical modulator has two electrodes located on its inner surface. However, as stated, multiple electrodes on one or both substrates are not required. For example, an embodiment of the optical modulator comprises a first substrate and a second substrate. For example, the first substrate may have one drive electrode, and the second substrate may not have a drive electrode. For example, the first substrate may have two drive electrodes, and the second substrate may have one drive electrode. For example, the first substrate may have two drive electrodes, and the second substrate may have two drive electrodes. For example, the first substrate may have three or more drive electrodes, and the second substrate may have two or more drive electrodes.

[0053] Optical modulators, however, with each substrate having two drive electrodes, are used as a motivational example. A substrate design featuring two drive electrodes may be adapted to have a single drive electrode, for example, by connecting the two drive electrodes or by removing one of the multiple drive electrodes. Adapting the substrate in this way may make it suitable for use in different technologies.

[0054] Each of the multiple drive electrodes is arranged in a pattern that crosses the substrate. The multiple drive electrodes are arranged alternately on the substrate relative to each other. Typically, each drive electrode has multiple main lines that extend across the substrate. The main lines of the drive electrodes are alternating, for example, interlocking. For example, in Figure 1b, the first drive electrode has main lines 111-114, and the second drive electrode has main lines 121-124. Each drive electrode is driven by its drive bus. Figure 1b shows two drive buses: drive bus 110 and drive bus 120. The drive electrodes also serve to connect the main lines together. For example, in Figure 1b, drive bus 110 drives and connects main lines 111-114; drive bus 120 drives and connects main lines 121-124. There can be more than four main lines than shown in this example. The use of main lines is advantageous because it reduces the length of the electrodes, but it is not necessary. While a design using only one main line per drive electrode is not impossible, having multiple main lines is advantageous.

[0055] Multiple main lines of the first and second electrodes are arranged alternately with respect to each other on the substrate.

[0056] In this example, there are no connections between the main lines of electrodes other than those passing through a common drive bus. In embodiments, the drive electrodes comprise a mesh electrode, i.e., the drive electrodes may have additional electrical connections that may be added between the electrode lines of the same drive electrode. This increases the reliability of the electrodes. Such additional connections typically intersect the electrode lines of another drive electrode, which may be resolved by positioning the additional electrical connections at a partially different level from the intersecting electrode lines with respect to the substrate. For example, the entire drive electrode may be positioned at a different level from another drive electrode. Thus, the additional connections may be positioned without causing a short circuit. Note that the aperture and its edges are at the same level as the electrode on which it is positioned.

[0057] Motivational applications for substrates such as substrate 100 may be applied in homes, offices, greenhouses, cars, and similar devices, such as smart glazing, for example, in optical modulators. The level of transparency or reflectivity of smart glazing can be electrically matched. For example, in smart glazing, two substrates such as substrate 100 are stacked such that the surfaces on which two electrodes are applied face each other. A fluid containing particles is confined between the two substrates. Embodiments of smart glazing are discussed further below. In embodiments, 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, two, or more electrodes may be present on other surfaces of substrate 100.

[0058] The following embodiments illustrate examples of modulating transparency or reflectivity levels. The optical modulator may be adapted for other optical effects. For example, if desired, the embodiments may be modified for different levels of translucency instead of different levels of transparency. If desired, the type of particles used in the embodiments may be varied, for example, for particles that absorb or reflect at different wavelengths and how specular or diffuse the reflection is. For example, in the embodiments, the optical modulator can modulate different levels of reflection. The particles may also emit light. Stacking multiple optical layers further increases the possibilities.

[0059] Having two sets of alternating main lines is sufficient to provide electrically adaptable glazing; the two alternating sets allow the electric field in any part of the substrate to be controlled because the two opposing electrodes demarcate that part from two opposing edges.

[0060] Interestingly, the pattern of the drive electrodes extending across the substrate is created by multiple repeating building blocks. As shown in Figure 1b, the drive electrodes on substrate 100 show four blocks: blocks 141, 142, 143, and 144, all of which are substantially identical. The number of building blocks may be more than four. The building blocks repeat across the substrate in both directions, for example, a first direction 191, e.g., the x-direction shown horizontally in the figure, and a second direction 192, e.g., the y-direction shown vertically in the figure. The use of building blocks is advantageous because it enables manufacturing using a stepper machine, and the use of building blocks is not necessary.

[0061] For example, Figure 1a schematically shows an example of an embodiment of building block 140. Building block 140 comprises a plurality of inter-mating electrodes extending in at least two directions across the building block. Four electrodes: electrodes 131-134 are shown in Figure 1a. When the building block is repeated across the substrate in two directions, the electrodes within the building block will form drive electrodes, for example, forming multiple main lines of drive electrodes. Note that building blocks are typically connected in a substrate electrode design tool. Typically, a building block has five or more electrode lines. For example, within the scope of the embodiment, between eight and twelve main lines are used. The number of electrode lines can, however, be much larger. For example, a building block may have many short electrode lines near the edges that connect to lines of other building blocks when the block is repeated. Taking such short derivatives into account, the number of lines can increase to, for example, 50. Obviously, using larger building blocks may also increase the number of electrode lines. In this embodiment, the number of electrode lines within the building block is between 8 and 50, or between 8 and 25, and so on.

[0062] The drive electrodes, formed by repeating building blocks, are connected to the drive bus. Typically, electrode lines within a building block are connected to electrode lines in neighboring blocks by merging the corresponding electrode lines; however, connection zones connecting the corresponding electrode lines may be inserted between repeating building blocks, although this is not necessary.

[0063] This step allows multiple main lines to be connected together, thus forming a single drive electrode. Figure 1b shows two connection zones 119 and 129, where main lines belonging to the same drive electrode are connected to drive bus 110 and drive bus 120, respectively.

[0064] The electrodes shown in Figure 1a are alternately marked with dashed lines in the same dashed line style as in Figure 1b. In practice, it happens in this example that certain electrodes of the building blocks in Figure 1a always end up either within the first drive electrode or within the second electrode, for example, as indicated by the dashed line style in this case. This, however, is not always the case. Electrodes within a building block may end up as part of the first drive electrode or as part of the second drive electrode. This can change, for example, the repeating pattern of the building blocks as a result of the even or odd number of electrodes within the building block.

[0065] For example, a particular pattern of repeating building blocks may be used for an optical modulator having two drive electrodes, in which alternating main lines may be assigned to the two drive electrodes. However, the same pattern of repeating building blocks may be used for an optical modulator having three drive electrodes, in which all adjacent sets of the three main lines may be assigned to the three drive electrodes.

[0066] Furthermore, although the building blocks shown in Figure 1a are square, this is not required. For example, the building blocks may be rectangular. In embodiments, the building block shape(s) may form a so-called tessellation. For example, the building blocks may be triangular, hexagonal, or even a combination of planar tessellations.

[0067] As stated, Figures 1a and 1b are schematic. This is especially true for the depiction of electrodes. The electrodes shown in Figure 1a are straight; however, in embodiments, electrodes on building blocks are more intricate, for example, curved. By adapting the shape of the electrodes, undesirable diffraction effects can be altered.

[0068] In embodiments, the dimmable mirror comprises an optical modulator according to the embodiment. For example, the dimmable mirror comprises 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. Typically, each substrate has two electrodes, but this is not necessary.

[0069] Figure 1c schematically shows an example of an embodiment of substrate 101. Substrate 101 is similar to substrate 100, except that the main lines formed from electrodes on the building blocks are connected to the drive bus. In Figure 1a, a connection zone is inserted between the repeating building blocks and the drive buses 110 and 120. In the connection zone, main lines belonging to the same drive electrode are connected to the same drive bus. In Figure 1c, the drive bus is directly adjacent to the building block. Part of the building block is modified to avoid the drive bus connecting to the main lines of different drive electrodes.

[0070] For example, building block 141 may be a copy of building block 140, but electrode 134 is shortened so that the main line 122, of which line 134 is part, does not connect to bus 110. In Figure 1c, the building blocks are substantially the same except that a disconnection is introduced in some electrodes of the building block adjacent to the drive bus to avoid connecting the main line to the drive bus. All building blocks shown in Figure 1c are thus modified, but in the embodiment, the majority of building blocks, such as those not adjacent to drive buses 110, 120, are not modified.

[0071] Figure 1d schematically shows an example of an embodiment of the substrate 102. In this embodiment, each electrode within a building block is connected to the same opposing edge of the building block. This results in the main lines formed by the electrodes on the building block connecting opposing edges of the substrate. In such a situation, having only two drive buses, each extending along opposing edges of the substrate, is sufficient to connect and drive the drive electrodes.

[0072] However, electrodes within a building block do not need to connect opposite edges of the building block. Typically, all electrodes within a building block will connect two edges of the building block, but these two edges do not need to be opposite. The reason for this is that electrodes may be continued by the next building block. In such situations, most main lines will still connect the same two opposite edges, but this may not happen at the edges of the substrate because there are no further building blocks to carry the electrodes forward. To allow for more complex electrode designs with respect to building blocks, main lines may connect to the drive bus from two edges, for example, two adjacent edges of the substrate at the same corner of the substrate.

[0073] Figure 1d shows a drive bus 110' extending along two sides of the substrate and a drive bus 120' extending along the other two sides of the substrate.

[0074] The advantage of this configuration is that the drive bus can be made in the same plane. However, this is not necessary. The drive bus can be connected from all three or four sides, if desired, to further increase the design freedom for the building block, for example. Various examples are shown herein.

[0075] It should be noted that drive electrodes, such as drive buses and / or main lines, can overlap. This is possible, for example, by creating a portion of dielectric material between the electrodes. For example, such overlapping electrodes may be partially or completely located in different planes of the substrate.

[0076] For example, in an embodiment, the first drive electrode may be deposed. Then, the dielectric is locally deposed, and finally, the second drive electrode is deposed. The dielectric is positioned to cover at least the points where the first and second electrodes intersect. Vias may be used for lower first drive electrodes, for example, to connect to a lower first drive electrode. Deposing of the drive electrodes may include deposing the drive bus.

[0077] Figure 1e schematically shows an example of an embodiment of the substrate 602. In Figure 1e, the building block is copied multiple times. To obtain the substrate 602, the building block is copied by repeated translation in the x and y directions. Each of the building blocks shown in Figure 1e can be obtained by the direct translation of any other building block.

[0078] A drawback of this configuration is that the drive buses of different drive electrodes ultimately face each other. To avoid short circuits, a small amount of space is left between the drive electrodes, for example, a width equivalent to 50 micrometers. Although not shown in Figure 1e, the various parts of the translated drive bus need to be connected together, for example, by electrode lines.

[0079] For example, as indicated by arrow 640, a vertical groove is formed; that is, two parallel electrode lines are close to each other. Similar grooves exist in the horizontal direction. Such grooves have been found to adversely affect diffraction. While a design with low diffraction may still be better than a pattern using inferior building blocks, it is desirable to avoid these grooves.

[0080] Figure 1f schematically shows an example of an embodiment of substrate 603. In substrate 603, the building blocks are repeated across the substrate but are positioned to avoid grooves, as in Figure 1e. In this embodiment, the building blocks are translated and mirrored in two directions.

[0081] Building block 611 is mirrored in the y-direction to form building block 621. Building block 621 is positioned directly below building block 611. Building block 611 is mirrored in the x-direction to form building block 612. Building block 612 is positioned directly to the right of building block 611. Building block 611 is mirrored in both the x-direction and the y-direction to form building block 622. For example, the mirroring may have the edges of the building block as the mirroring axis.

[0082] By mirroring the building blocks, it is ensured that the drive buses of the same drive electrode end up adjacent to each other on the substrate. Merging these drive buses avoids grooves and reduces diffraction.

[0083] In embodiments, at least the drive electrodes on the substrate have mirror symmetry; in embodiments, the drive electrodes and drive bus have mirror symmetry. For example, the substrate is symmetrical with respect to the x-axis and / or y-axis. This is a significant advantage during manufacturing because it allows the upper and lower substrates to be equal. Eliminating the need to produce separate substrates for the upper and lower parts of the optical modulator also eliminates the need to monitor separate types of substrates. Furthermore, having symmetry in the substrate allows a broken upper substrate to be replaced by a lower substrate, and vice versa, because they are the same. A straight line along the axis of mirror symmetry, for example, the drive bus, is useful because the design can be mirrored around that axis. Using building blocks in mirrored or non-mirrored forms helps to create a mirror-symmetric design.

[0084] This is particularly advantageous when manufacturing using a photolithography step for patterning the electrodes, because the same substrate patterning can be used for both substrates of the optical modulator, limiting production costs. The presence of straight busbars attached to the building blocks or parts of each building block facilitates this effect. Having a symmetrical design in one direction to use the same electrode pattern for all substrates is possible without straight busbars, for example, by local modifications of the electrode design at the edges of the symmetric lines. In embodiments, the driving electrode pattern has at least one symmetry in one direction, for example, by tiling the building blocks with a mirroring and / or rotatable electrode pattern design across the substrate.

[0085] An aperture may or may not be applied to the drive bus. The advantage of a drive bus without an aperture is that it has low resistance. On the other hand, since the drive bus may block light, an aperture may be applied to address this.

[0086] Figures 2a-2f schematically show examples of substrates having inter-mated electrodes. These may be embodied on the substrate using two electrodes, for example, by alternately connected electrodes. Figures 2a-2d may also be embodied on the substrate using multiple electrodes, for example, by connections in a sequence of three, four, or more electrodes.

[0087] Figures 2e and 2f show designs with two drive electrodes on the surface of the substrate. Both designs can be modified to have only a single drive electrode on the surface of the substrate, for example, by removing one of the two drive electrodes. Such a modified design could, for example, be used in an optical modulator using a substrate with a single electrode.

[0088] The designs shown can be realized in a single plane without intersecting electrodes. In particular, when these designs are connected to two drive buses, intersecting electrodes are not required. When three or more drive electrodes are used, or when more complex electrode patterns are used, electrode intersections may be used or even required. However, such intersections are possible, for example, where two electrode lines intersect a dielectric material that may be placed between the electrodes. For example, such an insulator may be deposited at the intersection site. For example, the first drive electrode is in a first plane of the substrate, and the second drive electrode is in a second plane of the substrate.

[0089] The two substrates according to the embodiment may 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.

[0090] Figure 3a schematically shows an embodiment of the optical modulator 10 that may be applied in smart glazing.

[0091] References are made to the patent application PCT / EP2020 / 052379, which is incorporated herein by reference; this application includes, for example, advantageous designs for optical modulators that can be further improved by including electrodes, buildable blocks, and / or substrates as described herein.

[0092] The optical modulator 10 can be electronically switched between a transparent state and a non-transparent state, and vice versa, or between a reflective state and a non-reflective state, and vice versa. The optical modulator 10 comprises a first substrate 11 and a second substrate 12 arranged opposite each other. At least two electrodes are applied to the inside of the first substrate 11: electrodes 13a and 13b are shown. These at least two electrodes together are called electrodes 13. At least two electrodes are applied to the inside of the second substrate 12: electrodes 14a and 14b are shown. These at least two electrodes together are called electrodes 14.

[0093] The fluid 15 is provided between the substrates. The fluid contains particles 30, such as nanoparticles and / or microparticles, which are electrically charged or can be charged. For example, particles may inherently have an electric charge on their surface. For example, particles may be surrounded by charged molecules.

[0094] The electrodes are positioned to drive the particles 30 to move toward or away from the electrodes, depending on the applied electric field. The optical properties of the optical modulator, in particular its transparency or reflectivity, depend on the location of the particles 30 in the fluid. For example, connections may be provided to apply an electromagnetic field to the electrodes.

[0095] At least one electrode, but preferably both electrodes 13 and 14, are shown schematically in the figures, according to the embodiment.

[0096] In the embodiment, at least one of the electrode patterns on the first substrate and the electrode patterns on the second substrate has a calculated low pixelation noise metric that contributes to diffraction. Interestingly, the electrode patterns on the substrates may not individually meet the limits regarding their pixelation noise metrics, but their combination, i.e., their superposition, may. Since this is the pattern that will be visible when viewed through the optical modulator, a low pixelation noise metric in the superposition will also contribute to low diffraction. Appropriate limits for the patterns on the first and / or second substrates or for the superposition include: less than 6.05%, 5%, or 4%.

[0097] In the example, substrates 11 and 12 may be optically transparent outside the electrodes, typically >95% transparent at the relevant wavelengths, e.g., >99% transparent. Considering the electrodes, transparency may be much lower, e.g., 70%. The term “optical” may, where applicable, relate to wavelengths visible to the human eye (approximately 380 nm–750 nm), and, where applicable, to a broader range of wavelengths including infrared (approximately 750 nm–1 μm) and ultraviolet (approximately 10 nm–380 nm) and their subselections. In exemplary embodiments of the optical modulator, the substrate material is selected from glass and polymer.

[0098] In another example, one substrate, such as the lower substrate 12, may be reflective or partially reflective, while the upper substrate 11 is transparent. The optical properties of the optical modulator, in particular its reflectivity, depend on the location of the particles 30 in the fluid. When the panel is open (vertically driven), the particles will be located approximately between the opposing electrodes of the two substrates, thereby allowing the incident light to pass through the transparent upper substrate and optical layer with relatively little obstruction and be reflected or partially reflected on the lower substrate.

[0099] The distance between the first substrate and the second substrate is typically 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, and more preferably less than 50 μm, for example, less than 30 μm.

[0100] In the example, the modulator may be made of a flexible polymer, and the rest of the device may be made of glass. The glass may be hard glass or flexible glass. If required, a protective layer may be provided on the substrate. If two or more colors are provided, two or more layers of flexible polymer may be provided. The polymer may be polyethylene naphthalate (PEN), polyethylene terephthalate (PET) (optionally having a SiN layer), polyethylene (PE), etc. In further examples, the device may be made of at least one flexible polymer. Thus, the modulator may be attached to any surface by means of an adhesive, for example.

[0101] Particle 30 may be adapted to absorb light, thereby preventing certain wavelengths from passing through. Particle 30 may reflect light; for example, the reflection may be specular, diffuse, or somewhere in between. Particles may absorb some wavelengths and reflect others. Particles may emit light, either similarly or instead, using, for example, phosphorescence, fluorescence, or similar phenomena. Even fluids may emit light whose emittance is modulated by changing the location of particles.

[0102] In exemplary embodiments of the optical modulator, the size of the nanoparticles ranges from 20–1000 nm, preferably 20–300 nm, and more preferably less than 200 nm. In exemplary embodiments of the optical modulator, the nanoparticles / microparticles include a pigment coating and may preferably include a core. In exemplary embodiments of the optical modulator, the particle coating is made from a material selected from conductive and semiconducting materials.

[0103] In an exemplary embodiment of the optical modulator, the particles are adapted to absorb light having wavelengths of 700 nm–1 μm and 10–400 nm, such as 10 nm–1 mm, 400–800 nm, and / or to absorb (filter) a portion of light having a wavelength range that falls within 10 nm–1 mm, and combinations thereof.

[0104] In an exemplary embodiment of the optical modulator, the particles are electrically charged or can be charged. For example, the charge on a particle is 0.1e to 10e per particle (5*10 -7 It may be -0.1C / m2.

[0105] In an exemplary embodiment of the optical modulator, the fluid is present in amounts such as 1-1000 g / m², preferably 2-75 g / m², more preferably 20-50 g / m², for example 30-40 g / m². A major advantage of this layout is that much less fluid and similar particles can be used.

[0106] In an exemplary embodiment of the optical modulator, the particles are present in amounts such as 0.01–70 g / m², preferably 0.02–10 g / m², for example, 0.1–3 g / m².

[0107] In an exemplary embodiment of the optical modulator, the particles have colors selected from cyan, magenta, and yellow, and from black and white, and combinations thereof.

[0108] In an exemplary embodiment of the optical modulator, the fluid comprises one or more surfactants, emulsifiers, polar compounds, and compounds capable of forming hydrogen bonds.

[0109] The fluid 15 may be a nonpolar fluid having a dielectric constant less than 15. In an exemplary embodiment of the optical modulator, the fluid has a relative permittivity εr less than 100, preferably less than 10, for example less than 5. In an exemplary embodiment of the optical modulator, the fluid 15 has a dynamic viscosity greater than 10 mPa·s.

[0110] Electrodes 13a, 13b and electrodes 14a, 14b are in fluid contact with a fluid. The fluid may be in direct contact with the electrodes, or indirectly, for example, the fluid may be in contact with a second medium having electrodes, such as through a porous layer. In embodiments, the electrodes cover about 1-30% of the substrate surface. In embodiments, the electrodes have an electrical conductivity > 1*10 (at 20°C). 7 The materials include electrically conductive materials having a resistivity less than 100 nΩm (at 273 K; for comparison, ITO, which is typically used, has 105 nΩm), similar to S / m. In embodiments of the optical modulator, the electrodes include 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.

[0111] A connection for applying an electromagnetic field to electrodes may be provided, where the applied electromagnetic field to the electrodes results in the movement of nanoparticles and microparticles from a first electrode to a second electrode and vice versa. For example, in an exemplary embodiment of an optical modulator, the current is between -100 and +100 μA, preferably -30 and +30 μA, and more preferably -25 and +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 within the optical modulator. For example, these aspects of power may be adapted by a controller.

[0112] The optical modulator 10 may have one or more segments, each segment being a single optically switchable entity whose size may vary. The substrate at least partially confines the volume that may be the segments.

[0113] This device may include driver circuits for changing the appearance of (individual) segments by applying an electromagnetic field. Therefore, similarly, the appearance of the optical modulator or one or more parts thereof may change. For example, the segments may be at least 1 mm in diameter. 2 It may have an area of ​​this size. This design allows for stacking to enable more colors; for example, in full-color applications, stacking two or three modulators may provide most or all of the colors, respectively. The aperture is not required for electrical isolation because the edges of the aperture are electrically connected. Filling the aperture with an electrically conductive material will not affect the operation of the optical modulator.

[0114] Having one or more segments allows for localized control of the optical modulator; this is advantageous for some applications, but not always necessary. In the case of smart glazing, the optical modulator may be used with or without segments. For example, when applied in smart glazing, transparency or reflectivity can be locally controlled, for instance, to prevent sun-patch without reducing the overall transparency or reflectivity of the window. Segments can be relatively large, for example, having a diameter of at least 1 mm or at least 1 cm.

[0115] In an exemplary embodiment of the optical modulator, the substrates (11, 12) are aligned and / or the electrodes (13, 14) are aligned. For example, electrodes 13a, 13b and electrodes 14a, 14b may be aligned so that they face each other. In aligned substrates, electrodes on different substrates are behind each other when viewed in a direction perpendicular to the substrates. When the optical modulator is disassembled and the substrates are together with the electrodes facing upward, the electrode patterns are mirror images of each other.

[0116] Aligning substrates may increase the maximum transparency or reflectivity of an optical modulator, while in some cases, when selecting an optical modulator for more criteria, such as a range of transparency or reflectivity, it may be better not to align the two substrates or to not align them completely. Optical modulators can be stacked. For example, two stacked optical modulators may be made from three substrates, with the central substrate having electrodes on both of its surfaces. In embodiments of the optical modulator, optionally, at least one substrate 11, 12 of the first optical modulator is the same as the substrate 11, 12 of at least one second optical modulator. In the case of stacked modulators, alignment may increase the maximum transparency or reflectivity, but it may be detrimental to other considerations, such as diffraction.

[0117] Figure 3b schematically shows an example of an embodiment of the optical modulator 40. The optical modulator 40 is similar to the optical modulator 10, except that it comprises multiple optical layers; two optical layers are shown in the example. There may be three or more optical layers. Each optical layer is located between two substrates. The optical modulator 40 can be considered a laminate of two-substrate optical modulators, as shown in Figure 3a. As shown, the optical modulator 40 comprises three substrates: a first substrate 41, a second substrate 42, and a third substrate 43. There is an optical layer between substrates 41 and 42, and an optical layer between substrates 42 and 43. The optical layers may be similar to the optical layers of the optical modulator 10. The controller 46 is configured to control the current on the electrodes of the substrates. For example, in Figure 3b, the controller 46 may be electrically connected to at least 4 × 2 = 8 electrodes.

[0118] Interestingly, particles within multiple optical layers may differ, so that multiple layers can be used to control more optical properties of the optical modulator. For example, particles in different optical layers may absorb or reflect at different wavelengths, and may have different colors, for example. This can be used by the controller 46 to create different colors and / or different color intensities on the panel. For example, a four-substrate panel may have three optical layers, each with different colored particles, e.g., cyan, yellow, and magenta. By controlling the transparency or reflectivity of different colors, a broad color spectrum can be created.

[0119] The surface of a substrate facing another substrate may be supplied with two or more patterns, for example, as in the embodiment. For example, the outer substrates 41 and 43 may receive electrodes only on their inner surfaces, while the inner substrate, for example, substrate 42, may have electrodes on both sides.

[0120] Substrates 41 and 42 may both be considered embodiments of an optical modulator. Similarly, substrates 42 and 43 may both be considered embodiments of an optical modulator.

[0121] Figure 3c schematically shows an example of an embodiment of a car 20 having smart glazing for a window 21. This is a particularly advantageous embodiment because the level of incident light can be changed frequently and rapidly while driving. Using smart glazing in a car has the advantage that the light level can be maintained at a constant level by adjusting the transparency of the car's windows. Furthermore, the reduced diffraction effect improves safety by reducing driver distraction. The car 20 may include a controller configured to control the transparency or reflectivity of the window 21.

[0122] Smart glazing can be used in other glazing applications where the amount of incident light is variable, such as in buildings, offices, homes, greenhouses, and skylights. A skylight is a window placed in the ceiling to allow sunlight to enter a room.

[0123] An optical modulator may have two optical states, for example, a transparent state and an opaque state or a reflective state and an antireflective state. An optical modulator, for example, optical modulator 10 or optical modulator 40, - By creating an alternating current voltage on at least one of the first and second substrates and applying an alternating current between at least a first electrode and a second electrode on the first substrate and / or between a first electrode and a second electrode on the second substrate, a second optical state, for example, an opaque state or an anti-reflective state, - Switch to a first optical state, e.g., a transparent state or a reflective state, by creating an alternating voltage between the first substrate and the second substrate, and applying an alternating current between the first electrode on the first substrate and the first electrode on the second substrate, and / or between the second electrode on the first substrate and the second electrode on the second substrate. It may be configured in this way.

[0124] The electrode pattern on the first substrate is at least partially arranged in the same pattern as the second electrode on the second substrate. Typically, the electrodes face each other, but the patterns of the first and second electrodes may be shifted relative to each other.

[0125] A protective coating may be provided on at least a portion of at least one inner surface area of ​​the first substrate and the second substrate.

[0126] In one embodiment, at least one substrate is transparent. In another embodiment, the first substrate and / or the second substrate are transparent.

[0127] The drive signal applied to the drive electrode typically has a varying voltage. For example, a power supply may operate at an AC frequency to switch between a transparent and an opaque state. Such a signal may have a frequency between, for example, 1-1000 Hz. A balanced electrolytic current may be obtained by continuously switching the polarity of oppositely charged electrodes on and / or between the first and second substrates.

[0128] Figures 4a-4b schematically show side views of an embodiment of an optical modulator in use. Applying an electric field to electrodes on a substrate induces an electric force on particles. Using this effect, particles can move around, and thus different transparent or reflective states can be induced within the optical modulator. A controller may control the electric field, for example, its amplitude, frequency, and phase. In embodiments, the controller is connected to at least four electrodes: two electrodes for each substrate. However, more electrodes may be used and connected to the controller; for example, three or more electrodes may be used for a substrate to better fine-tune grayscale and drive it into an opaque or non-reflective state. Multiple electrodes may also be used to support multiple segments on a substrate.

[0129] Figure 4a shows an optical modulator in a state where no electric field is applied. In Figure 4a, no electric force is yet applied to the particles 30 suspended in the fluid 15.

[0130] In the configuration shown in Figure 4a, the conductive electrode pattern on the upper substrate is perfectly or substantially aligned with the conductive electrode pattern on the lower substrate. The conductive electrode pattern may be deposited on a transparent or (partially) reflective glass substrate, or embedded in a plastic substrate or the like.

[0131] Alignment between the upper and lower electrode patterns contributes to a wider range of achievable levels of transparency or reflectivity. However, alignment is not necessary, as similar effects can be obtained without alignment. A similar range of transparency or reflectivity can be obtained without alignment.

[0132] Note that in these examples, references to the upper and lower boards refer to the board that is higher or lower on the page. The same board may also be referred to as, for example, the front board and the rear board, because in glazing applications, the boards will be aligned vertically rather than horizontally.

[0133] Figure 4b shows an optical modulator, where, for example, in instance P1, a potential +V1 is applied to each microwire electrode on the upper substrate, while a negative voltage, for example -V1, is applied to each microwire electrode on the lower substrate. Therefore, in this case, the same positive potential is applied to all electrodes 13, and the same negative potential is applied to electrode 14. The potential difference causes negatively charged particles to flow near the electrodes on the upper substrate, where the particles substantially align with the upper electrodes. As a result, if both the upper and lower substrates are transparent, the transparency of the optical modulator 10 will increase. Similarly, if, for example, the upper substrate is transparent and the lower substrate is reflective, and the solution contains positively charged particles that flow near the electrodes on the lower substrate, where these particles substantially align with the lower electrodes, the reflectivity of the optical modulator 10 will increase.

[0134] Similar transparency or reflectivity can be achieved in a second instance P2 in the ON state, where the voltages of the upper and lower electrodes are inverted in contrast to instance P1. In instance P2, the voltage of each electrode on the upper substrate is supplied with a negative potential -V1, while the voltage of the aligned electrodes on the lower substrate is supplied with a positive potential. This state is similar to the state shown in Figure 4b, but the upper and lower substrates are inverted. In this configuration, the transparency or reflectivity of the optical modulator 10 is similarly high.

[0135] Interestingly, transparency or reflectivity can be maintained while reducing corrosion damage to the electrodes by switching between, for example, the positive potential of the electrode on the upper substrate (and the negative potential on electrode 14), shown as electrode 13 in Figure 4b, and the positive potential of the electrode on the lower substrate, shown as electrode 14 in Figure 4b. This alternating electric field can be achieved by applying an alternating potential to the upper and lower electrodes.

[0136] Applying an AC waveform is optional but a useful measure to increase the lifespan of the optical modulator by reducing corrosion. Corrosion can form, for example, when using copper electrodes, because copper ions dissolve in the ionic fluid on one substrate and flow to the electrode on the opposing substrate, where the copper ions deposit. By applying the waveform, the direction of copper ion transport is frequently reversed, thus reducing corrosion damage. Between two instances P1 and P2, the corrosion currents between the two substrates are balanced, or substantially balanced, for example, >95%, for example, when a corrosion rate occurs on the electrode of the upper plate, there is a balanced deposition of copper on the lower electrode between instances P1 and in the same way between instances P2. Thus, particles continuously migrate or move between the upper and lower electrodes, the optical modulator or smart window is always on, while the dynamic electrolytic current between the upper and lower electrodes is constant, and therefore the net loss of electrode material on the upper and lower electrodes is zero or negligible.

[0137] Figure 4c shows how a reduced transparency or reflectivity state can be obtained. An AC voltage is applied to the same substrate. For example, in an embodiment, as shown in Figure 8c, a potential +V2 is applied to the first electrode, and the next immediately adjacent electrode has the opposite potential -V2, and so on. This can be achieved by applying a potential +V2 to electrode 13a and the opposite potential -V2 to electrode 13b. On the opposing substrate, a potential +V2 may be applied to electrode 14a and the opposite potential -V2 to electrode 14b. For example, the electrodes may be arranged so that the electrodes on the substrate are aligned; an electrode on the upper substrate has a counter electrode on the lower substrate, and vice versa. For example, to reduce transparency or reflectivity, the counter electrodes may receive the same potential, while the neighboring electrodes receive the opposite potential. An embodiment is shown in Figure 4c, where the four electrodes are indicated by reference numerals 13a, 13b, 14a, and 14b, and the rest of the electrodes follow in an alternating manner.

[0138] By using AC drive cycles between the upper and lower substrates, oblique and transverse electric fields are generated between the two substrates, thereby causing random diffusion of particles and creating a closed state of the optical modulator. As a result of this configuration, particles move obliquely and transversely between the upper and lower substrates, and the diffusion of particles into the visible aperture of the optical modulator contributes to the closed opaque state of the optical modulator.

[0139] Regarding the transparent state shown in Figure 4b, the waveform may be applied to the electrodes such that, for example, the electrode shown in Figure 4b becomes negative when it has a positive potential, and vice versa. Similar to the case of Figure 4b, applying the waveform between electrodes 13a and 13b, and between 14a and 14b, for example, reduces corrosion damage to the electrodes.

[0140] The AC drive cycle may be implemented by using a mutually mated line configuration that combines upper and lower electrode configurations, as shown in the plan view in Figures 1a, 1b, 2a-2f, etc.

[0141] The degree to which transparency or reflectivity increases or decreases in Figures 4b and 4c depends on the voltage and frequency difference. By changing the voltage difference, the amount by which transparency or reflectivity increases or decreases, respectively, can be controlled. For example, a curve representing light transmittance versus voltage may be determined, for example, by measurement. To obtain a specific level of light transmittance, for example, a specific level of transparency, for example, a specific grayscale level, a corresponding voltage, for example, an AC voltage, may be applied. Levels between transparent and opaque may be obtained by interpolating the signal for transparent or opaque states. Similarly, a curve representing light reflectance versus voltage may be determined, for example, by measurement. To obtain a specific level of reflectivity, a corresponding voltage, for example, an AC voltage, may be applied. Levels between reflective and non-reflective may be obtained by interpolating the signal for reflective or non-reflective states.

[0142] Different electrode patterns may be used for optical modulators. Each electrode pattern may provide a certain range of grayscale, e.g., levels of transparency or reflectivity, that the optical modulator can achieve. However, the specific range of grayscale for any given electrode pattern may differ from that of another electrode pattern. In other words, different patterns may give an increase in transparency or reflectivity or an increase in opacity, but the precise response to the drive signal depends on many factors, including the specific pattern used. Variations in the optical properties of an optical modulator can have fine resolutions, for example, less than 1 mm. Note that pixilation of the optical modulator is not required to achieve different visible optical patterns in the optical modulator, e.g., a logo.

[0143] This effect can be used to embed visible images into an optical modulator by locally altering the electrode pattern on the substrate of the optical modulator. For example, different electrode patterns may locally have grayscales with a permanent grayscale offset from each other. For example, maximum transparency or reflectivity may be altered by locally changing the electrode pattern or its pitch.

[0144] The result is areas on the optical modulator having different intensities of grayscale, e.g., different grayscales, or different intensities of coloration. The areas may, however, have the same color point. In embodiments, they may switch together with the rest of the window, albeit at different speeds. For example, even if the same voltage is applied to electrodes in two different areas, they will cause different transparency states, e.g., different transmission levels, due to different electrode patterns. For example, the curve representing transmittance versus voltage may be shifted. For example, if voltage control is changed in the same way in both areas, the light transmittance in both areas may change, but by different amounts. Areas may also be made less responsive to the drive signal by reducing the density of electrodes; in particular, areas may be made not to switch at all, for example, by not applying electrodes within the area.

[0145] For example, electrode materials may include copper, aluminum, gold, and indium-tin oxide (ITO). ITO is transparent, while Cu / Al is reflective; therefore, different electrode materials may be used to obtain different appearances, regardless of the driving voltage. Similarly, different materials with different resistances will produce different electric fields. For example, ITO will have a smaller electric field even when driven by the same voltage.

[0146] An embodiment of the method for modulating light includes applying a potential to a plurality of driving electrodes applied to a substrate according to two opposing embodiments to obtain an electromagnetic field between the plurality of driving electrodes that causes the electrophoretic motion of particles toward or from one of the plurality of driving electrodes, resulting in modulation of light shining through the substrate, the two opposing substrates being as in the embodiments.

[0147] Figures 5a.1–7b schematically show examples of substrate and aperture embodiments. At least one driving electrode is applied to the surface of the substrate. Typically, two inter-mating driving electrodes are applied to the surface of the substrate. The driving electrodes extend in a pattern across the surface of the substrate, for example, to control local electric field modulation. The substrate shown in the figure may be placed in an optical modulator. Typically, at least one or both of the substrates are transparent, so at least a portion of the light for at least a portion of the visible spectrum passes through the substrate. Typically, a substrate with perforated electrodes applied to it is transparent. The same is true for other types of radiation. For example, the transmission of infrared light may be increased by providing an aperture.

[0148] Similarly, the electrodes may be transparent. For example, at least one driving electrode on the substrate, or all electrodes on the substrate, or all electrodes on both opposing substrates, may contain ITO. In embodiments, the transparent substrate may have opaque electrodes, for example, the electrodes may contain metal. The opaque electrodes are perforated and therefore less visible than they would normally be.

[0149] In particular, the two substrates shown in the figure may be placed facing each other within the optical modulator, with an optical layer containing a fluid containing particles positioned between the first substrate and the second substrate.

[0150] The motion of particles toward or away from an electromagnetically-dependent driving electrode causes modulation of the optical properties of the optical modulator. In particular, the electrophoretic effect may be used to move charged particles.

[0151] Figure 5a.1 schematically shows an example of an embodiment of the substrate 500. Figure 5a.1 shows two interlocking drive electrodes applied to the surface of the substrate. The drive electrodes extend in a pattern that crosses the surface of the substrate.

[0152] In this case, the driving electrode comprises an electrode line extending on the substrate. The electrode line comprises a plurality of apertures. For example, the electrode line may extend along the longitudinal direction and along the transverse direction, and the longitudinal extension is at least 10 times, more preferably at least 100 times, longer than the transverse extension in at least a portion of the line electrode.

[0153] The electrode lines of the drive electrodes are inter-mating with each other. For example, the electrode line of the first drive electrode is inter-mating with the electrode line of the second drive electrode. Facing edges of a continuous electrode line have, for example, a minimum distance of at least 20 microns between facing edges. The electrode line extends in length and width dimensions, the width being less than 100 microns.

[0154] Figure 5a.1 shows detail 509 of the drive electrode. Detail 509 schematically shows multiple apertures that perforate the drive electrode, for example, extending through the electrode and thus allowing incident radiation to pass through the first substrate and the drive electrode into the optical layer, or vice versa. While some embodiments of this specification are described for applications of light, such as visible light, such embodiments may be adapted for infrared light instead.

[0155] An aperture within an electrode does not contain an electrically conductive material, but is surrounded on all sides by an electrically conductive material. A partial aperture is partially surrounded by an electrically conductive material. In embodiments, one or more electrodes have at least 100, preferably at least 500, and more preferably at least 1000 apertures.

[0156] Perforation may be applied to other electrode patterns, for example, as shown in Figures 2a-2f. Perforation may be applied in various ways.

[0157] The driving electrode is typically a line electrode. The line electrode may extend along the longitudinal direction and along the transverse direction, and the extended portion is at least 10 times, more preferably at least 100 times, longer in the longitudinal direction than the transverse extension portion, at least in local portions of the line electrode.

[0158] The various sizes of the substrate embodiment may relate to the size of the particles intended to be used. One metric for a particle is its average diameter. If the particle is spherical, the diameter may be considered to be twice the radius. If the particle is non-spherical, the diameter may be defined as the minimum upper limit of the set of all distances between pairs of points within the particle. The aperture diameter, for example, the minimum upper limit of the set of all distances between pairs of points within an aperture, may be defined in the same way. If the aperture is a disk, this definition coincides with the definition of the diameter.

[0159] The aperture size, for example, the average aperture diameter, may be related to the size of the particles used in the optical layer. For example, the average aperture diameter may be 5 to 50 times larger than the average particle diameter. The average line width of the driving electrode may be 5 to 50 times larger than the average aperture diameter. The line width may be considered as the shortest distance from a certain point on the edge to a certain point on the opposite edge of the same electrode.

[0160] As a non-limiting example, for instance, the driving electrodes may have line widths in the range of, for example, 10–100 micrometers, and the widths, or line gaps, between them may be within the same range. For example, the minimum line gap between electrodes may be, for example, 20 micrometers, and the average line gap may be, for example, 50 micrometers. The particles may have an average diameter of up to 500 nanometers. The average aperture diameter may be at least 1 micrometer.

[0161] The aperture distribution may also depend on the particle size. This is further shown in Figures 6a-6c.

[0162] The aperture may have various effects: making the electrodes less visible to the user of the optical modulator, reducing diffraction, and increasing the effect of the electric field. The diameter of the aperture may be further selected to increase a specific wavelength range by the plasmon effect.

[0163] In an optical modulator according to an embodiment, the driving electrodes may be applied to both substrates. For example, this may be the case in the case of an electrophoretic optical modulator. Typically, the driving electrodes on opposing substrates are aligned with each other; however, this is typical but not practically necessary. Both electrodes on opposing substrates may be perforated, for example, provided with apertures. If this is done, the apertures may or may not be aligned. Unaligned apertures have the advantage of being easier to manufacture and avoiding optical artifacts. Due to stray light, the transmission of light through the optical modulator is also increased. Furthermore, an improved electric field is maintained even if one or more or all of the apertures are not aligned. For example, if the orthogonal projection of the aperture onto the other substrate does not overlap with the aperture on the other substrate, the apertures are not aligned. On the other hand, the apertures may be aligned as desired. Aligned apertures have the advantage that the same design for the electrode mask can be used for both substrates, although typically mirrored. Instead of being perfectly aligned, apertures may also be partially aligned.

[0164] Arranging apertures on two substrates so that they are not aligned or partially aligned may be done by offsetting the aperture on one substrate relative to the aperture on the other substrate. The aperture locations may also be arranged independently of the two substrates.

[0165] Figure 5a.2 schematically shows an example of an aperture embodiment. Many shapes are possible for apertures. For example, an aperture can be circular. Circular apertures are adaptable to various manufacturing techniques. For example, a circular aperture may be fabricated by a laser or similar.

[0166] The aperture does not have to be circular and can have various shapes. In embodiments, the aperture is part of a mask for the electrode design. Such a mask may be used in a photolithography process to transfer the electrode design onto a substrate. For example, a stepper may be used to repeatedly apply one or more building blocks.

[0167] For example, an aperture may be elongated, for example, elliptical. For example, an aperture may be polygonal. A circle has perfect radial symmetry. The advantage of using a shape that does not have perfect radial symmetry, for example, a shape with a finite number of radial symmetries, for example, a shape with no radial symmetry, is the possibility of randomizing the aperture design by rotating the aperture.

[0168] Figure 5a.2 shows possible aperture shapes, which include: circles, ellipses, squares, squares of revolution, triangles, and triangles of revolution.

[0169] Many of the exemplary embodiments shown herein use circular or elliptical apertures, but these may be modified to use apertures of other shapes.

[0170] Figure 5b schematically shows an example of an embodiment of tessellation or tiling. Tessellation may be used to generate apertures of a fixed pattern. Tessellation covers a plane, for example, a substrate, using one or more geometric shapes, also called tiles. The number of geometric shapes may be one or more. Tessellation includes vertices and edges between vertices. For example, a vertex may be a common point between three tiles. One vertex is identified as vertex 504 in Figure 5b.

[0171] Apertures may be positioned where the electrodes intersect the vertices of the tessellation. The density of apertures within the drive electrode may be controlled by changing the size of the tessellation relative to the substrate.

[0172] Many tessellations, such as hexagonal tiling and square tiling, are known in the art. Tessellations may be periodic; for example, a tessellation may have a subset of shapes that can be translated to cover an entire plane. An example of aperiodic tiling is Penrose tiling, which is also an example of tiling that uses two different geometric shapes. Using aperiodic patterns has the advantage that the resulting aperture distribution is also aperiodic and therefore non-constant. Using aperiodic tessellations to generate aperture locations has the advantage that the aperture locations will be aperiodic, but will still have upper and lower limits on their density depending on the size(s) of the geometric shape(s) of the tessellation.

[0173] Generally speaking, a constant aperture distribution has the effect of better predictability of the resulting electric field and optical effects. A non-periodic aperture distribution has the effect of better low diffraction.

[0174] In an embodiment, the aperture is positioned at the apex only if it is completely contained within the electrode. In an embodiment, the aperture is positioned at the apex only if it is at least a threshold distance from the edge of the electrode. For example, the threshold may be at least the average diameter of the aperture.

[0175] The apertures applied to the vertices of the tessellation may, for example, be the same size, as shown in Figure 5c below, but this is not required. Apertures of different sizes may be used instead. The size of the apertures may or may not follow a constant, for example, periodic distribution.

[0176] The vertices of a periodic tessellation are an example of a two-dimensional grid. More generally, a grid may be used to determine aperture locations. Instead of tessellation being required to generate a grid, the grid may instead be defined by a grid basis containing, for example, multiple grid basis vectors.

[0177] Figure 5c schematically shows an example of an embodiment of electrode 503. Note that in detail 509 of Figure 5a.1 and in Figure 5h, the electrode material is shaded, but this is not done in most of the other figures.

[0178] Figure 5c shows electrode edges 501 and 502. The distance between the electrode edges is the line width 505, which is schematically shown in Figure 5c as a dashed line 505.

[0179] Figure 5c shows several apertures applied to the electrode. One of the apertures is indicated by the number 510. An aperture allows radiation, such as light, to pass from the substrate through the electrode, and vice versa. The aperture distribution shown in Figure 5c is periodic and constant. The aperture distribution shown in Figure 5c was applied using the tessellation shown in Figure 5b.

[0180] Figure 5d schematically shows an example of an electrode embodiment. The electrode in Figure 5d is the same as the electrode in Figure 5c, except that an elliptical aperture is used instead of a circular aperture. The apertures are located in the same fixed positions, but rotation is applied to them. In the figure, the rotation is applied according to a constant, for example, periodic pattern. Apertures 511-514 are shown. These apertures are rotated by 0, 45, 90, and 135 degrees, respectively. This is not necessary because the rotation applied may be random, for example, drawn from a probability distribution.

[0181] Figure 5e schematically shows an example of an electrode embodiment. The electrode in Figure 5e is the same as the electrode in Figure 5c, except that the line width is smaller relative to the average aperture diameter. Furthermore, no threshold is enforced between the electrode edge and the aperture. As a result, in this example, several apertures are applied only partially.

[0182] The electrode material, e.g., metal, e.g., copper, e.g., ITO, or similar, is sometimes removed (or not applied) in a complete aperture, in this case in the shape of a circle, and sometimes only partially removed. One partial aperture is shown in 520. As a result, the electrode edge 521 is here serrated. The advantage of a serrated edge is that the length of the electrode edge is increased without a correspondingly large reduction in the electrode area.

[0183] In Examples 5c-5e, the tessellation is aligned with the electrode before applying the aperture. This is not necessary. For example, the tessellation may have an angle with respect to the electrode. For example, the tessellation may be fixed relative to the plane.

[0184] For example, in low-diffraction electrode designs where the electrode orientation is randomized, as in Figures 2f and 5a.1, it is preferable to locally align the tessellation with the electrode. This avoids creating a constant aperture distribution across the entire substrate, which may increase diffraction. For example, a transformation may be used to map the electrode or a portion of the electrode to a straight line. The aperture distribution on the straight line may then be transformed back to the electrode using an inverse transformation. The transformation is preferably a diffeomorphism.

[0185] An overly uniform structure on an optical modulator can lead to diffraction, which is generally considered a drawback. This can be particularly problematic in optical modulators where all substrates are transparent, such as in dynamic glazing. Therefore, there is a desire to randomize the aperture distribution. Various randomization possibilities exist, and multiple possibilities may be combined. Figure 5d shows one way of doing so, for example, by rotating the aperture. The rotation may also be randomized.

[0186] Figure 5f.1 schematically shows an example of an electrode embodiment. The electrode in Figure 5f.1 is the same as the electrode in Figure 5c, except that the aperture positions are randomized. The aperture distribution in Figure 5f.1 is constant, e.g., periodic, except that the randomization shift is applied to one or more or all of the apertures, in this case all of the apertures. For example, Figure 5f.2 schematically shows an example of a shift embodiment. For example, the original aperture 522 and the shifted aperture 523 by tessellation are shown. The shift from the original aperture 522 to the shifted aperture 523, e.g., the vector, may be randomly selected. For example, the coordinates of the vector may be derived from a random probability distribution. The probability distribution may be a uniform distribution, but other distributions are also possible, in this case, for example, a two-dimensional Gaussian distribution may be used.

[0187] For example, the shifts may be selected sequentially for each aperture.

[0188] Figure 5g.1 schematically shows an example of an electrode embodiment. The aperture locations in Figure 5g.1 are randomly selected, resulting in a non-deterministic pattern.

[0189] For example, additional constraints may be applied regardless of how the aperture distribution is randomized, such as by rotation, shifting, or random location. For example, one or more of the following constraints may be enforced on the randomized aperture distribution, in particular, if the locations are randomized, for example, by shifting or randomly generating the aperture locations.

[0190] - Apertures should not overlap partially or completely, because this can result in less or more aperture than intended. - The conductivity of the electrodes should not be too high, for example, reduced beyond a threshold, and in particular, the aperture should not cause the electrode to break, for example, to separate or nearly separate a part of the electrode from another part of the electrode. If the conductivity becomes too low, the ability of the optical modulator to effectively modulate light will be impaired.

[0191] - The local density of apertures across the substrate preferably does not have excessive fluctuations, for example, not exceeding a threshold, because this can be visible in optical modulators. This constraint may be intentionally broken, for example, for signage. For example, the local density for a given region may be defined as the ratio of the aperture area to the region area within that region. For example, a rectangular region of 10 × 10 micrometers may be used to calculate the local density across the substrate.

[0192] Figure 5g.2 schematically shows an example of an embodiment of aperture 531. After aperture 531 is positioned, an exclusion zone 532 is drawn around aperture 531. For example, the exclusion zone 532 may have the same shape but be proportionally larger than aperture 531. If the next aperture is positioned on the electrode within the exclusion zone, the positioning is skipped or modified.

[0193] Figure 5h schematically shows an example of an embodiment of electrode 540. Details of electrode 540 are shown. Electrode 540 is an example of a non-straight electrode. Furthermore, electrode 540 is an example of a branched electrode, for example, a split electrode. For example, electrode 540 may be used in an electrode design having a curved electrode, such as the design in Figure 2f or Figure 5a.1.

[0194] The electrode edge may be defined by a series of line segments, for example, a polygonal chain. The electrode edge may also be defined by a spline or a series of spline segments. Electrode 540 enters in three consecutive directions, for example, directions 541-543. Randomly placed apertures are added to the electrode, subject to constraints, for example, a minimum distance between the aperture edge and the electrode edge and a lower limit on the aperture density to ensure sufficient conductivity. One aperture is marked with the number 544.

[0195] If the randomization of the arrangement would violate the constraints, a new randomization method may be chosen. For example, the algorithm may be as follows:

[0196] 1. Obtain the electrode pattern for the substrate. 2. Select a random location within a given aperture. 3. If the selected location is not skipped, verify that the constraint is met, and if not, impose the constraint. 4. Verify whether the stopping criteria are met, for example, that there is no further progress in aperture placement, that the maximum number of apertures is exceeded, that the maximum execution time is exceeded, or any combination thereof. If not, continue to step 2.

[0197] Regardless of the arrangement, the minimum distance may be forced between different aperture edges on the same electrode or between two points on the electrode edge. This also suggests a lower limit on aperture density. The minimum distance may depend on the average diameter of the particles. For example, the minimum distance may be at least twice the average diameter of the particles.

[0198] Figure 6a schematically shows an example of an electrode embodiment. Only the upper electrode edge 601 is shown in the figure. Two apertures 650 and 602 are shown in Figure 6a. In the configuration of Figure 6a, a constraint is imposed that the minimum distance between any two points on different edges on the same electrode, such as an aperture or electrode edge, should be greater than a minimum threshold, such as twice the average particle size.

[0199] For example, a point 651 is given on the edge of aperture 650. The distance between point 651 and any point on electrode edge 601 should be greater than a threshold. In particular, the nearest point on edge 601 should have a greater distance. The nearest point and its distance are indicated by vector 652.

[0200] For example, point 651 is given on the edge of aperture 650. The distance between point 651 and any point on aperture edge 602 should be greater than a threshold. In particular, the nearest point on edge 602 should have a greater distance. The nearest point and its distance are shown by vector 653.

[0201] Therefore, the lengths of vectors 652 and 653 should be longer than the threshold in order to satisfy the constraint on point 651.

[0202] Figure 6b schematically shows an example of an electrode embodiment. In Figure 6b, only the upper electrode edge 601 and one aperture 650 are shown. A point 654 on the electrode edge is given. The distance between point 654 and any point on the aperture edge 650 should be greater than a threshold. In particular, the nearest point on edge 650 should have a greater distance. The nearest point and distance are indicated by vector 655.

[0203] In embodiments, the minimum distance between two points on different aperture edges on the same electrode, and between the point on the aperture edge and the point on the electrode edge, is at least 300 nanometers or at least 700 nanometers. This condition is particularly advantageous when the improvement in radiation tolerance is directed towards visible light, because the wavelength of visible light ranges from 380 nm to 700 nm.

[0204] Complexity can arise with respect to partial apertures, such as serrated electrode edges. Figure 6c schematically shows an example of an electrode embodiment. Figure 6c corresponds to Figure 6a, but has additional serrations 656, for example, partial apertures intersecting the electrode edge. In addition to the distances shown in Figure 6a, Figure 6c also shows the nearest distance to the serrations, indicated by vector 657. Note that with respect to the serrations, only points that are part of the electrode edge and not part of an aperture corresponding to removed or unapplied electrode material are considered.

[0205] Calculating distances to enforce these types of constraints is O(n) by considering each pair of n points to verify the distance constraints. 2This may be done in the algorithm. A linear algorithm that may be applied to efficiently calculate the distance between sets of points, as described in the paper "Distance Transforms of Sampled Functions" (by Pedro F. Felzenszwalb and Daniel P. Huttenlocher).

[0206] Figure 7a schematically shows an example of an electrode embodiment having a low-density region 711 and a high-density region 712. The number of apertures per unit area of ​​the electrode or the area of ​​apertures per unit area of ​​the electrode is lower in region 711 than in region 712. Such differences may be visible to the naked eye. For example, transitions in region 712 may be faster due to a more efficient electric field. Furthermore, aperture density may also be directly visible, especially with proper illumination. Although not shown in Figure 7a, there may be regions without apertures, for example. Often, a uniform appearance of the optical modulator is desired, but this is not necessary and may be utilized. Patterns of aperture density, for example, patterns of higher and lower density regions, may form a visible image. The image may be used for any reason, for example, to display signage.

[0207] Figure 7b schematically shows an example of an electrode embodiment. Figure 7b shows a random arrangement. Here, similarly, the aperture size, e.g., its diameter, is randomized in this case by expanding and contracting the aperture. Allowing different sizes makes it easier to satisfy density constraints with lower and upper limits. Allowing smaller apertures between larger apertures makes it easier to increase aperture density while still satisfying the minimum distance constraint.

[0208] Aperture distributions can also be obtained by randomizing a constant aperture distribution, such as the distribution in Figure 5c. Randomization may involve aperture shifting and aperture resizing.

[0209] The aperture diameter may be randomly selected from a continuous scale, for example, or it may be selected from a discrete set of diameters.

[0210] The following numbered list of clauses is an example of what is intended. They are examples of embodiments.

[0211] Optical modulator Clause 1. An optical modulator, - A first substrate and a second substrate, arranged with their inner surfaces facing each other, the first substrate being transparent, at least one drive electrode applied to the inside of the first substrate, the drive electrode extending in a pattern across the inside of the first substrate, between the first substrate and the second substrate, - An optical layer disposed between a first substrate and a second substrate, containing a fluid containing particles, - A controller configured to apply a potential to at least one driving electrode to obtain an electromagnetic field that provides motion for particles toward or away from the driving electrode, thereby causing modulation of the optical properties of the optical modulator, - An optical modulator having a driving electrode comprising multiple apertures extending through the electrode, thereby allowing incident radiation such as light to pass through the first substrate and the driving electrode into the optical layer, or vice versa.

[0212] Clause 1.1. The aperture is circular, as described in Clause 1.

[0213] Article 2. - The average aperture diameter is at least twice the average particle diameter. - More preferably, the optical modulator according to Clause 1, wherein the average diameter of the aperture is 5-50 times larger than the average diameter of the particles.

[0214] Clause 3. The optical modulator according to Clause 1 or 2, wherein the minimum distance between two points on different aperture edges or electrode edges on the same electrode is at least twice the average diameter of the particle.

[0215] Clause 4. A light modulator as described in any one of Clauses 1 to 3, having multiple apertures having multiple different diameters.

[0216] Clause 5. The average line width of the drive electrode is 5 to 50 times greater than the average diameter of the aperture, as described in any one of Clauses 1 to 4.

[0217] Clause 5.1. An optical modulator as described in any one of Clauses 1 to 5, wherein the aperture is distributed across the drive electrodes at varying densities.

[0218] Clause 5.2. A part of the driving electrode does not include an aperture, as described in any one of Clauses 1 to 5.1 of the optical modulator.

[0219] Clause 6. An optical modulator as described in any one of Clauses 1 to 5.2, wherein multiple apertures are randomly distributed across at least a portion of the electrodes.

[0220] Clause 7. An optical modulator according to any one of Clauses 1 to 6, wherein at least one driving electrode comprises an ITO electrode.

[0221] Clause 8. An optical modulator according to any one of Clauses 1 to 7, wherein at least one driving electrode is applied to the inside of a second substrate, the driving electrode extends in a pattern traversing the inside of the second substrate, and the controller is configured to apply a potential to at least one driving electrode on the first substrate and the second substrate, the driving electrode on the second substrate having a plurality of apertures extending through the electrode, so that incident radiation such as light can pass through the second substrate and the driving electrode into the optical layer, or vice versa.

[0222] Clause 9. One or more drive electrodes on the first substrate are aligned with one or more electrodes on the second substrate, however, - The apertures in one or more drive electrodes of the first substrate and the second substrate are not aligned, and / or - At least a portion of the apertures in one or more drive electrodes of the first substrate and the second substrate are partially aligned, and / or - The optical modulator according to Clause 8, wherein apertures in one or more drive electrodes of the first substrate and the second substrate are offset relative to each other.

[0223] Clause 10. The particles are electrically charged or can be charged, and the controller is configured to apply a potential to a driving electrode to obtain an electromagnetic field that provides electrophoretic motion of the particles toward or away from the driving electrode, thereby causing modulation of the optical properties of the optical modulator, as described in any one of Clauses 1 to 9.

[0224] Clause 10.1. The optical modulator according to Clause 10, wherein a plurality of mutually mated drive electrodes are arranged across the inside of a first substrate and a second substrate, and the controller is configured to apply an electrical signal to the plurality of electrodes to obtain an electric field between the plurality of electrodes that provides electrophoretic motion of particles, thereby causing modulation of the optical properties of the optical modulator.

[0225] Article 10.2. The optical modulator, - Switch to an opaque state by creating an alternating voltage on at least one of the first substrate and the second substrate, and applying an alternating current between at least the first electrode and the second electrode on the first substrate and / or between the first electrode and the second electrode on the second substrate. - An optical modulator according to Clause 10 or 10.1, configured to switch to a transparent state by creating an alternating voltage between a first substrate and a second substrate and applying an alternating current between a first electrode on the first substrate and a first electrode on the second substrate and / or between a second electrode on the first substrate and a second electrode on the second substrate.

[0226] Clause 10.3. An optical modulator as described in any one of Clauses 10 to 10.2, where the electrical signal is an AC signal.

[0227] Clause 10.4. The particle is charged or chargeable, and the particle is moved by an electrophoretic force, and the optical modulator according to any one of Clauses 1 to 10.3.

[0228] Clause 11. The aperture has a specific diameter and increases a specific wavelength range, and the optical modulator according to any one of Clauses 1 to 10.4.

[0229] Clause 12. The particle is charged or chargeable, and the particle is moved by an electrophoretic force, and the optical modulator according to any one of Clauses 1 to 11.

[0230] Clause 13. The drive electrode is a line electrode. For example, the line electrode extends along the longitudinal direction and the transverse direction, and the extension is at least 10 times, more preferably at least 100 times longer in the longitudinal direction than in the transverse direction at least in a local portion of the line electrode, and the optical modulator according to any one of Clauses 1 to 12.

[0231] Clause 15. - The transparent state and the non-transparent state, and / or - The reflective state and the non-reflective state The optical modulator has, and is configured to switch between states by modulating the current between one or more drive electrodes applied to the first substrate and optionally one or more drive electrodes applied to the second substrate, and the optical modulator according to any one of Clauses 1 to 13.

[0232] Clause 16. - The electrical signal is provided as an alternating current (AC) at one or more electrodes, or - The electrical signal is provided as a direct current (DC) at one or more electrodes, and the voltage is periodically reversed, and the optical modulator according to any one of Clauses 1 to 15.

[0233] Clause 16. The first substrate and the second substrate are transparent, and the optical modulator according to any one of Clauses 1 to 16.

[0234] Clause 17. An optical modulator according to any one of Clauses 1 to 16, wherein one of the first substrate and the second substrate is transparent, and one of the first substrate and the second substrate is reflective or partially reflective.

[0235] Clause 18.1 or more electrodes comprise multiple interlaced mesh electrodes, - An optical modulator according to any one of Clauses 1 to 17, wherein multiple interlaced mesh electrodes extend in a two-dimensional pattern across a first substrate and across a second substrate, and two mesh electrodes of the multiple mesh electrodes on the substrate intersect at multiple intersection points extending across the substrate.

[0236] Article 19. - The particles are nanoparticles and / or microparticles, and / or - Particles are adapted to absorb light. - The particles are pigment particles, as described in any one of Clauses 1 to 18.

[0237] Clause 20. An optical modulator according to any one of Clauses 1 to 19, wherein at least two electrodes include an electrically conductive material having a resistivity of less than 100 nΩm at 273 K.

[0238] Clause 21. An optical modulator according to any one of Clauses 1 to 20, wherein the electrodes are in fluid contact with the fluid, or the electrodes are separated from the fluid, for example, by a coating.

[0239] Clause 22. The electrodes applied to the substrate shall cover 1-30% of the substrate surface and shall be optical modulators as described in any one of Clauses 1 to 21.

[0240] Clause 23. An optical modulator as described in any one of Clauses 1 to 22, which operates at an AC frequency of 10–100 Hz to switch to a transparent state and / or at an AC frequency of less than 1 Hz to switch to an opaque state.

[0241] Clause 23. The optical modulator according to any one of Clauses 1 to 23, wherein the size of the nanoparticles is 10-1000 nm, preferably 100-500 nm.

[0242] Clause 24. A light modulator as described in any one of Clauses 1 to 23, wherein the particles are adapted to absorb light having a wavelength of 10 nm to 1 micron.

[0243] Clause 25. An optical modulator as described in any one of Clauses 1 to 24, wherein the distance between the first substrate and the second substrate is less than 500 μm.

[0244] Clause 26. An optical modulator as described in any one of Clauses 1 to 25, wherein the kinematic viscosity of the fluid is 500 mPa·s or less.

[0245] Clause 27. The fluid shall have a relative permittivity ε less than 100. r An optical modulator having any one of the clauses 1 to 26.

[0246] method Article 28. A method for modulating light, A method for modulating light, comprising applying a potential to one or more driving electrodes applied to one or two opposing substrates, thereby obtaining an electromagnetic field between the driving electrodes that provides electrophoretic motion of particles toward or from one of the plurality of driving electrodes, causing modulation of light shining through the substrates, wherein at least one or both of the two opposing substrates are as described in any one of Clauses 1 to 27.

[0247] A method for modulating light as described in Clause 28, comprising using a two-phase alternating current having a potential between -220V and +220V and a current between -100μA and +100μA.

[0248] A non - transient or transient computer - readable medium containing data representing instructions, which, when executed by a processor system, cause the processor system to perform the method according to clause 28 or 29.

[0249] Clause 30. A method of manufacturing a substrate, comprising: - Providing a substrate, which is transparent, for use in an optical modulator; - Applying at least one drive electrode to a surface of the substrate, the drive electrode extending in a pattern across the surface of the substrate, the drive electrode comprising a plurality of apertures extending through the electrode, thereby enabling incident radiation, such as light, to pass through the substrate and the drive electrode, or vice versa.

[0250] Substrate Clause 31. A substrate according to any one of clauses 1 to 30.

[0251] Clause 32. A substrate for use in an optical modulator, which is transparent, at least one drive electrode being applied to a surface of the substrate, the drive electrode extending in a pattern across the surface of the substrate, the drive electrode comprising a plurality of apertures extending through the electrode, thereby enabling incident light to pass through the substrate and the drive electrode, or vice versa.

[0252] Clause 33. The substrate for use in an optical modulator according to clause 32, wherein the pattern of the drive electrode across the substrate comprises a plurality of repeating building blocks.

[0253] Clause 34. - The building blocks repeat across the substrate in at least two directions and / or - A plurality of different building blocks repeat across the substrate in one or two directions. The substrate according to any one of clauses 32 to 33

[0254] Clause 35. At least one drive bus is provided on the substrate for each drive electrode of at least one drive electrode to drive the drive electrode. - At least one drive bus is positioned on the surface of the substrate for each drive electrode to drive the drive electrode, and / or - The drive bus is simply located on the surface of the board, and / or - The drive bus is located between building blocks covering the board, as described in any one of clauses 32 to 34.

[0255] Clause 36. A substrate that is non-rectangular, as described in any one of Clauses 32 to 35.

[0256] Clause 37. At least one drive electrode comprises multiple drive electrodes, - A substrate for use in an optical modulator as described in any one of Clauses 32 to 36, wherein multiple drive electrodes (111-114, 121-124) are mated to each other, each of the multiple drive electrodes is arranged in a pattern across the substrate, the multiple mated drive electrodes are arranged alternately to each other on the substrate, and the pattern of the multiple drive electrodes across the substrate comprises multiple repeating building blocks.

[0257] Article 38. Building blocks are, - A substrate for use in an optical modulator according to Clause 37, comprising a plurality of inter-mated electrodes extending in at least two directions across a building block, wherein the inter-mated electrodes within the building block form a drive electrode for at least one electrode within the plurality of inter-mated electrodes within the building block, and the maximum length between any two points on the electrode measured along the electrode within the building block is at least twice the length of the diagonal of the building block unit.

[0258] Clause 39. At least one drive electrode comprises multiple drive electrodes, - The shortest distance from any point on the substrate to the first drive electrode and to the second drive electrode is shorter than a threshold, and / or - The sum of the closest distance from any point on the substrate to the first drive electrode and the closest distance to the second drive electrode is less than the first threshold and / or greater than the second threshold and / or - The distance from a certain point on the first drive electrode to a certain point on the second drive electrode is at least the second threshold, and / or - A substrate for use in an optical modulator as described in any one of Clauses 32 to 38, wherein the horizontal and / or vertical size of the building block is at least 10 times the sum of the electrode line width and electrode distance.

[0259] Figure 8a shows a computer-readable medium 1000 having a writable portion 1010 containing a computer program 1020, and also a computer-readable medium 1001 having a writable portion containing a computer program. The computer program 1020 includes instructions, according to embodiments, for causing a processor system to operate an optical modulator. For example, the processor system may be connected to an optical modulator panel. The computer program 1020 may be embodied as a physical mark on the computer-readable medium 1000 or by magnetization of the computer-readable medium 1000. However, any other suitable embodiments are conceivable. Furthermore, although the computer-readable medium 1000 is shown here as an optical disc, it will be recognized that the computer-readable medium 1000 may be any suitable computer-readable medium such as a hard disk, solid memory, flash memory, etc., and may be non-recordable or recordable. The computer program 1020 includes instructions for causing the processor system to perform the optical modulator method.

[0260] Figure 8b shows a schematic diagram of a processor system 1140 according to an embodiment of a controller for an optical modulator. The processor system comprises one or more integrated circuits 1110. The architecture of one or more integrated circuits 1110 is schematically shown in Figure 8b. Circuit 1110 includes a processing unit 1120, e.g., a CPU, for executing computer program components to perform the method according to the embodiment and / or implement a module or unit thereof. Circuit 1110 includes a memory 1122 for storing programming code, data, etc. Part of the memory 1122 may be read-only. Circuit 1110 may include communication elements 1126, e.g., an antenna, a connector, or both, and similar. Circuit 1110 may include a dedicated integrated circuit 1124 for performing some or all of the processing defined in the method. The processor 1120, memory 1122, dedicated IC 1124, and communication elements 1126 may be connected to each other via an interconnect 1130, e.g., a bus. The processor system 1110 may be configured for contact and / or contactless communication using antennas and / or connectors, respectively.

[0261] For example, in an embodiment, the processor system 1140, for example, the device, may comprise a processor circuit and a memory circuit, the processor being configured to execute software stored in the memory circuit. For example, the processor circuit may be an Intel Core i7 processor, an ARM Cortex-R8, etc. In an embodiment, the processor circuit may be an ARM Cortex-M0. The memory circuit may be a ROM circuit or non-volatile memory, such as flash memory. The memory circuit may be volatile memory, such as SRAM memory. In the latter case, the device may comprise a non-volatile software interface configured to provide software, such as a hard drive, a network interface, etc.

[0262] For example, a controller for an optical modulator that controls the voltage applied to an electrode may include a processor circuit, or similarly, or instead, a state machine.

[0263] It should be noted that the embodiments described above are illustrative, not limiting, the subject matter currently disclosed, and that many alternative embodiments can be designed by those skilled in the art.

[0264] Any reference numerals placed between parentheses in a claim shall not be construed as limiting the claim. The use of the verb “comprise” and its conjugations shall not preclude the existence of elements or steps other than those stated in the claim. The articles “a” or “an” preceding an element shall not preclude the existence of multiple such elements. Expressions such as “at least one of” preceding a list of elements shall represent a selection of all or any subset of the elements from the list. For example, the expression “at least one of A, B, and C” should be understood as including 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 now disclosed may be implemented by hardware comprising several distinct elements and by a appropriately programmed computer. In a device claim enumerating several parts, some of these parts may be embodied by one of the same items of hardware. The mere fact that certain measures are cited in different dependent claims does not indicate that combinations of these measures cannot be used to one's advantage.

[0265] In the claims, references in parentheses refer to reference numerals in the drawings illustrating embodiments or to the formulas of embodiments, and thus enhance the clarity of the claims. These references shall not be construed as limiting the claims.

Claims

1. It is an optical modulator, - A first substrate and a second substrate, arranged with their inner surfaces facing each other, and at least one patterned drive electrode applied to the inner surface of the first substrate, the drive electrode extending in a pattern across the inner surface of the first substrate, the first substrate and the second substrate, - An optical layer containing a fluid containing particles, which is placed between a first substrate and a second substrate. - A controller configured to apply a potential to at least one drive electrode to obtain an electromagnetic field that provides motion for particles toward or away from the drive electrode, thereby causing modulation of the optical properties of the optical modulator. Equipped with, - An optical modulator comprising a driving electrode having multiple apertures extending through the electrode, thereby allowing incident radiation to pass through the first substrate and the driving electrode into the optical layer, or vice versa.

2. - The incident radiation includes infrared radiation, and / or - The incident radiation includes visible light, The optical modulator according to claim 1.

3. - The average aperture diameter is at least twice the average particle diameter, more preferably the average aperture diameter is 5-50 times larger than the average particle diameter, and / or - The average aperture diameter is smaller than the average width of the drive electrodes, more preferably the average width of the drive electrodes is 5-50 times larger than the average aperture diameter, and / or - The combined area of ​​multiple apertures is smaller than the combined area of ​​the drive electrodes excluding the apertures, more preferably the combined aperture area is less than 50% of the combined drive electrode area, and / or - Multiple apertures having multiple different diameters, and / or - The minimum distance between two points on different aperture edges or electrode edges on the same electrode is at least twice the average diameter of the particle, and / or - The minimum distance between two points on different aperture edges or electrode edges on the same electrode is at least 300 nanometers or at least 700 nanometers. The optical modulator according to claim 1 or 2.

4. The drive electrode comprises an electrode line having multiple apertures, - The opposing edges of the continuous electrode line have a minimum distance between opposing edges of at least 20 microns, preferably at least 10 microns, and / or - The electrode line extends in length and width dimensions, and the width is a maximum of 10 cm, preferably a maximum of 1 mm, preferably a maximum of 100 microns, preferably a maximum of 1 micron. An optical modulator according to any one of claims 1 to 3.

5. The optical modulator according to any one of claims 1 to 4, wherein the driving electrode comprises a mesh electrode.

6. The optical modulator according to any one of claims 1 to 5, wherein the drive bus is applied to a first substrate and configured to deliver power from the edge of the substrate to the drive electrode, and the drive bus does not have an aperture applied to the drive bus.

7. The optical modulator according to any one of claims 1 to 6, wherein multiple apertures are randomly distributed across at least a portion of the electrode.

8. The optical modulator according to any one of claims 1 to 7, wherein at least one driving electrode comprises an ITO electrode.

9. An optical modulator according to any one of claims 1 to 8, wherein at least one driving electrode is applied to the inside of a second substrate, the driving electrode extends in a pattern traversing the inside of the second substrate, and a controller is configured to apply a potential to at least one driving electrode on the first substrate and the second substrate, the driving electrode on the second substrate comprises a plurality of apertures extending through the electrode, thereby allowing incident radiation to pass through the second substrate and the driving electrode into the optical layer, or vice versa.

10. One or more drive electrodes on the first substrate are aligned with one or more electrodes on the second substrate, however, - The apertures in one or more drive electrodes of the first substrate and the second substrate are not aligned, and / or - At least a portion of the apertures in one or more drive electrodes of the first substrate and the second substrate are at least partially aligned, and / or - Apertures in one or more drive electrodes of the first substrate and the second substrate are offset from each other. The optical modulator according to claim 9.

11. The optical modulator according to any one of claims 1 to 10, wherein the particles are electrically charged or can be charged, and the controller is configured to apply a potential to one or more drive electrodes to obtain an electromagnetic field that provides electrophoretic motion of particles toward or away from the drive electrodes, thereby causing modulation of the optical properties of the optical modulator.

12. The optical modulator according to any one of claims 1 to 11, wherein the aperture has a specific diameter and increases transmission within a specific wavelength range.

13. A substrate for use in an optical modulator, wherein at least one driving electrode is applied to the surface of the substrate, the driving electrode extends in a pattern across the surface of the substrate, and the driving electrode has a plurality of apertures extending through the electrode, so that incident radiation can pass through the substrate and the driving electrode, or vice versa.

14. A method for manufacturing a circuit board, - A substrate for use in an optical modulator, which is transparent, is provided. - Applying at least one drive electrode to the surface of the substrate A method comprising a driving electrode extending in a pattern across the surface of a substrate, the driving electrode having multiple apertures extending through the electrode, and thus allowing incident radiation to pass through the substrate and the driving electrode, or vice versa.

15. A method for manufacturing a substrate according to claim 14, comprising patterning a drive electrode, wherein an aperture may be created after or during the patterning of the drive electrode.

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