Light modulator, substrate with electrodes, and smart glazing

Abstract

Some embodiments relate to a light modulator comprising a transmissive or reflective substrate, where a plurality of electrodes are applied to the substrate in a pattern across the substrate, and a controller can apply potentials to the electrodes to obtain an electromagnetic field between the electrodes that results in electrophoretic movement of particles towards or away from the electrodes.

Description

[Technical field]

[0001] The subject matter of the present disclosure relates to optical modulators, substrates, optical modulator methods, and computer-readable media. [Background technology]

[0002] US Patent Application No. 11 / 041,579, "Optically active glazing," Publication No. US20050185104A1, discloses known optically active glazing and is incorporated herein by reference.

[0003] This known system comprises two parallel plates of a transparent dielectric material, such as glass or a plastic material. The internal volume defined between the plates is subdivided into a number of separate small volumes or individual cells filled with a dielectric liquid. This liquid contains a suspension of particles of the dielectric material. The opposing faces of the two plates carry mutually opposing electrodes. These electrodes are connected to a power source associated with control means.

[0004] The electrodes on each plate have a comb shape that is interleaved with each other in pairs. The electrodes of the two interleaved combs can be voltaged with the same or opposite polarities. With the appropriate voltage on the electrodes, particles can be collected at various locations between the electrodes to give the system the appearance of either transparency or opacity.

[0005] There are various drawbacks associated with this known system. When the known glazing is in its transmissive configuration, the electrodes applied to the plates generate diffraction effects. Diffraction effects are undesirable for glazing. In some circumstances, the presence of diffraction effects may also be detrimental to safety. For example, when the optically active glazing is applied to a vehicle such as an automobile, the presence of diffraction may be confusing or distracting for the operator of the vehicle.

[0006] Furthermore, the operation of this known system can be improved.

[0007] Another drawback of known systems is that in an opaque configuration, it is desirable for the glazing to appear uniform. This aspect may also have safety implications. For example, if the glazing is configured intermediate between opaque and transparent, the lack of uniformity may be confusing or distracting.

[0008] Yet another drawback is that when the glazing transitions from an impermeable configuration to a transmissive configuration, it is desirable for the transition to proceed at a uniform rate across the glazing. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] US Patent Application Publication No. 2005 / 0185104 [Patent Document 2] European Patent Application Publication No. 2020 / 052379 [Non-patent literature]

[0010] [Non-Patent Document 1] "Numerical comparison of grid pattern diffraction effects through measurement and modeling with OptiScan software", Murray et al., published May 20, 2011, SPIE journal (doi:10.1117 / 12.883422) Summary of the Invention [Problem to be solved by the invention]

[0011] It would be beneficial to have an improved substrate on which the two electrodes are distributed that addresses the above and other issues. The inventors have discovered that the electrode designs in known systems result in diffraction and also in an electric field that is not perfectly uniform. Addressing the first issue results in a substrate on which less diffraction can be applied. Addressing the second issue contributes to a more uniform opacity state across the substrate and a more uniform transition rate. [Means for solving the problem]

[0012] Smart glazing is an important application of transparent or reflective substrates to which electrodes are applied. For example, transparent or reflective substrates for applications such as smart glazing may have two electrodes, each with a number of main lines. These lines are arranged alternately on the substrate, so that by providing a potential difference to the electrodes, an electric field can be established between subsequent or adjacent lines.

[0013] From these main lines, multiple branch lines may extend. By extending the branch lines at least halfway across the distance between the two main lines, better homogeneity and / or lower diffraction effects may be obtained. Furthermore, two subsequent branch lines that extend into the same area between a first main line and a second main line may overlap in the second direction when projected in the first direction. These branch lines increase the number of angles seen by the substrate, thereby reducing diffraction effects. For example, angles different from perpendicular may be chosen and / or may be varied to further reduce diffraction. Diffraction can also be reduced by varying the distance between the main line and the subsequent main line on the substrate.

[0014] Substrates according to the embodiments may be used in light modulators, also known as optical modulators. For example, two such substrates may be placed opposite each other, so that by applying a voltage to the electrodes, charged particles suspended in a fluid between the substrates can be moved. Typically, the electrode designs for the lower and upper substrates are identical, but this is not required. Similarly, the two designs are typically aligned with each other, but this is also not required. The particles may absorb or reflect light. The reflection may be specular, diffuse, or something in between. The particles may emit light, for example with phosphorescence or fluorescence.

[0015] The light modulator provides a panel whose transmittance or reflectance can be modified. In an embodiment, the color or color intensity etc. may be changed. The light modulator may be used as a cover, for example a cover for a container such as a closet, cabinet etc. A particularly useful application is in smart glazing, also called smart windows.

[0016] In an embodiment, the controller is configured to apply a potential to the electrodes on the substrate of the light modulator to obtain an electromagnetic field between the electrodes. This electromagnetic field results in electrophoretic movement of the particles towards or away from the electrodes. When the particles change position, the optical properties of the panel change, for example its transmittance or reflectance. If the particles are colored, the color of the panel may also change. By changing the electrode pair between which the electric field is established, the particles can be moved in a desired direction. The inventors have discovered that control of the light modulator need not be limited to only changing the electrodes between which the electric field is applied, but can also include changing the maximum amplitude. It should be noted that, advantageously, an alternating current is used. For example, the rate of change in the light modulator is changed by driving with a lower maximum amplitude. This is advantageous because, for example, the maximum amplitude can be reduced to avoid overshoot when driving towards a desired target transmittance or reflectance. The maximum amplitude can also or alternatively be increased when starting to drive towards the target transmittance or reflectance. For example, by using an AC voltage of one of a plurality of maximum amplitudes, the controller can be configured to obtain one of a plurality of levels of transmittance or reflectance in the light modulator. This relationship can be indicated by an algorithm or the like. The relationship between the level of transmittance or reflectance and the maximum amplitude can be managed, for example, by a look-up table indicating a series of maximum amplitudes that drive towards the transmittance or reflectance. It should be noted that an AC voltage is also possible.

[0017] Varying the maximum amplitude of the drive signal in addition to varying the electrodes between which the signal is applied can also be used to improve balanced driving. For example, the power, e.g., maximum amplitude, applied on some electrodes may be different than that applied to other electrodes. For example, the controller may be configured to apply a potential difference between subsequent electrodes on the same substrate while simultaneously applying a potential difference between opposing electrodes on opposing substrates.

[0018] In an embodiment, there are at least two electrodes on each substrate, but there may be more than two electrodes. For example, at least three electrodes may be applied to at least one of the first substrate and the second substrate. For example, in an embodiment, two electrodes may be applied to the first substrate and three electrodes may be applied to the second substrate.

[0019] A system in which one substrate has at least two electrodes and the other substrate has at least three electrodes has various advantages. For example, such a light modulator may be driven in such a way that the so-called curtain effect is reduced. This curtain effect occurs during closing of a window, where it appears as if a curtain is drawn between the electrodes. This curtain effect is a drawback, essentially visually distracting, and also increases diffraction. On the side with three electrodes, the electrodes can be closer together than on the side with two electrodes, for example less than 50 microns, more preferably less than 40 microns, for example 35 microns closer together. This means that the electric field is stronger. Correspondingly, closing is faster and the curtain effect is reduced. When a 2+2 panel moves the electrodes closer together, this may lead to a reduction in the maximum transmission or reflectance. However, this is avoided if additional electrodes are available. When open, some of the additional electrodes may be unused, and thus the loss of maximum transmission or reflectance is small. Additional electrodes on the substrate, for example more than two electrodes, may be configured to not attract particles when the panel is open, but to attract particles when the panel is closed. For example, a panel with each substrate having at least two electrodes can have a total of at least four electrodes. The substrates in the panel can have at least five electrodes, for example in a 2+3 design; or at least six electrodes, for example in a 2+4 or 3+3 design; or at least eight electrodes, for example in a 4+4 design, or as two 2+2 designs using three substrates stacked together, with the middle substrate having two electrodes on each side.

[0020] A further aspect of the invention is a building comprising a light modulator according to the embodiment. A further aspect of the invention is a vehicle comprising a light modulator according to the embodiment. For example, the vehicle and / or the building may comprise a light modulator and a controller configured to control the transmittance or reflectance of the light modulator by controlling a voltage on an electrode of the light modulator, the controller being electrically connected or connectable to the light modulator.

[0021] Smart glazing is an electronic device and may be powered by a power source under the control of, for example, a controller, which may instruct the power source to apply specific waveforms to specific electrodes to achieve various transmission or reflection effects, or lack thereof.

[0022] The method embodiment may be implemented on a computer as a computer-implemented method, or may be implemented in dedicated hardware, or a combination of both. The executable code of the method embodiment may be stored in a computer program product. Examples of computer program products include memory devices, optical storage devices, integrated circuits, servers, online software, etc. Preferably, the computer program product includes non-transitory program code stored on a computer-readable medium for performing the method embodiment when said program product is executed on a computer.

[0023] In an embodiment, the computer program comprises computer program code configured to perform all or part of the steps of the method embodiments when the computer program is run on a computer. Preferably, the computer program is embodied on a computer readable medium.

[0024] Further details, aspects and embodiments are described, by way of example only, with reference to the drawings in which elements are illustrated for simplicity and clarity and have not necessarily been drawn to scale. In the figures, elements corresponding to elements already described may have the same reference numerals. The drawings include: [Brief description of the drawings]

[0025] [Figure 1a] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 1b] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 1c] 1A-1C are schematic diagrams illustrating examples of embodiments of branch lines. [Figure 1d] FIG. 2A-C show schematic examples of embodiments of first and second electrodes arranged in a pattern across a substrate. [Figure 2a] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 2b] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 2c] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Diagram 3] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 4a] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 4b] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 4c] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 5a] 1A-1D are schematic diagrams illustrating several examples of embodiments of a substrate. [Figure 5b] 1A-1C are schematic diagrams illustrating examples of embodiments of substrates configured for two or three electrodes. [Figure 6a] FIG. 13 is a diagram illustrating a comparative example of a substrate. [Figure 6b] FIG. 13 is a diagram illustrating a comparative example of a substrate. [Figure 6c] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 6d] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 7a] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 7b] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 7c] FIG. 1 shows a schematic diagram of an example embodiment of a motor vehicle. [Figure 8a] 1A and 1B are schematic diagrams illustrating embodiments of an optical modulator; [Figure 8b] 1A and 1B are schematic diagrams illustrating embodiments of an optical modulator; [Figure 8c] 1A and 1B are schematic diagrams illustrating embodiments of an optical modulator; [Figure 9a] 1A-1C are schematic diagrams illustrating examples of logo and grid embodiments. [Figure 9b] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 9c] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 9d] 1A-1D are schematic diagrams illustrating examples of embodiments of a substrate. [Figure 10] 1A-1C are schematic diagrams illustrating examples of embodiments of light modulator methods for controlling a light modulator. [Figure 11a] 1 illustrates a schematic diagram of a computer readable medium having a writeable portion comprising a computer program according to an embodiment; [Figure 11b] FIG. 2 is a schematic diagram illustrating a representation of a processor system according to an embodiment. [Figure 12] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 13] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 14] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 15] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 16] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 17]1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 18] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 19] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 20] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 21] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 22] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 23] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 24] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Diagram 25] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 26] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 27] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 28] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 29] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Diagram 30] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Diagram 31] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Diagram 32] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Diagram 33] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Diagram 34] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Diagram 35] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Diagram 36] 1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; [Figure 37]1A and 1B are schematic diagrams illustrating examples of embodiments of optical modulators; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] List of reference numbers The following list of reference symbols and abbreviations is provided to facilitate interpretation of the figures and is not to be construed as limiting the scope of the claims. 10 Optical Modulator 11 First substrate 12 Second board 13, 13a, 13b electrode 14, 14a, 14b electrode 15 Fluid 16 Controller 30 particles 20 cars 21 Optical Modulator 40 Optical Modulator 41 First substrate 42 Second Board 43 Third Board 46 Controller 100 Substrates 101 First Direction 102 Second Direction 110 First electrode 120 Second electrode 111-113 Main line 121-123 Main line 131-134 Branch line 141-144 Branch line 150 Area 151 Half the distance between two following main lines 152 Distance between two subsequent branches 153 Distance between two subsequent main lines 161 Projection 162 Virtual Line 171-174 PCB 200 boards 201-206 Main line 251-253 Distance between subsequent main lines 221 First Part 222 Connection 223 Second Part 231 Line Spacing 232 distance 300 Substrates 301 Main line 310, 320 Sub-main line 311 Connection 321, 322 Sub-main line 400 Substrates 410, 420 Main line 411, 412 branch line 421,422 branch lines 450 Substrate 451-454 Block

[0027] The subject matter of the present disclosure is susceptible of embodiment in many different forms, one or more specific embodiments are shown in the drawings and described in detail herein, with the understanding that the disclosure is considered as an example of the principles of the subject matter of the present disclosure and is not intended to be limited to the specific embodiments shown and described.

[0028] In the following, for the sake of understanding, elements of the embodiments are described in terms of their operation, although it is to be understood that each element is configured to perform the functions described as being performed by it. Furthermore, the subject matter disclosed herein is not limited to the embodiments, but also includes other combinations of each of the features described herein or recited in different dependent claims.

[0029] FIG. 1a is a schematic diagram of an example embodiment of a substrate 100. There are at least two electrodes arranged in a pattern across the surface of the substrate 100. In FIG. 1a, two electrodes are shown on the same surface: a first electrode 110 and a second electrode 120. There may be more than two electrodes on the same side of the substrate, for example to facilitate finer control. For example, multiple electrodes may be used to facilitate a segmented substrate, for example for a segmented light modulator. For example, in a segmented light modulator, some zones may have different optical properties, for example different transmittance or reflectance. In the following, an embodiment with two electrodes is shown, but additional electrodes may be added to the two, for example by replicating similar structures next to each other.

[0030] The first electrode 110 and the second electrode 120 are applied to the same side of the substrate. These two electrodes are arranged in a pattern across the substrate. One, two or more electrodes may be present on the other surface of the substrate 100, for example to facilitate stacking of three or more substrates. Applying the electrodes to the substrate may be done by lithography, for example using a mask representing the electrode pattern. The electrodes may be applied by embedding them in the substrate.

[0031] The first electrode 110 and the second electrode 120 each include a plurality of main lines. As shown in FIG. 1a, the first electrode 110 includes main lines 111, 112, and 113, and the second electrode 120 includes main lines 121, 122, and 123. Typically, each electrode includes more than three lines. The main lines extend across the substrate. The main lines of the plurality of first and second electrodes are arranged alternately with respect to each other on the substrate. The main lines extend across the substrate in a first direction 101. Looking in a second direction 102, the main lines are encountered alternately from different plurality, for example from the first and second plurality in the first and second electrodes, respectively. The first and second directions are at an angle to each other, typically the angle being approximately perpendicular. The first and second directions may each be parallel to a side of the substrate, but this is not required.

[0032] An ambitious application for substrates such as substrate 100 is in smart glazing, e.g., light modulators, which may be applied in homes, offices, greenhouses, automobiles, etc. The level of transmission or reflectivity of smart glazing may be configured electrically. For example, in smart glazing, two substrates such as substrate 100 may be stacked, whereby the sides on which the two electrodes are applied face each other. A fluid with particles is enclosed between the two substrates. An embodiment of smart glazing is further described below. In an embodiment, an electrode, e.g., two or more electrodes, is applied to one surface of each substrate. For example, one, two, or more electrodes may be present on the other surface of substrate 100 to facilitate stacking of three or more substrates.

[0033] Some of the embodiments below provide examples of modulating the transmissivity or reflectivity levels. The light modulators can be configured for other optical effects. For example, the embodiments can be modified to have different translucency levels instead of different transmissivity levels, if desired. If desired, the types of particles that can be used in the embodiments can be modified, for example, to particles that absorb or reflect different wavelengths, and how specular or diffuse the reflection is. For example, in embodiments, the light modulators can modulate different reflectivity levels. The particles can also emit light. Stacking multiple optical layers provides even more possibilities.

[0034] Having two sets of alternating principal lines is sufficient to provide an electrically configurable glazing; because of the two alternating sets, the electric field in any part of the substrate can be controlled such that two opposing electrodes bound the part from two opposing sides. However, very straight principal lines without further modification would result in high levels of diffraction, which is undesirable.

[0035] By adapting the electrode shape, the diffraction effect can be changed. Reducing the diffraction effect is particularly important for transparent substrates, since the effect is not significant for reflective displays, such as those that may be applied in e-book readers. The inventors have discovered that light diffraction can be reduced by orienting the electrode line shapes at several different angles to spatially spread out the diffraction, thus reducing the brightness of the most concentrated diffraction spots.

[0036] Fig. 1a shows a schematic representation of a main line without various decorations according to an embodiment. In Fig. 1a, for the sake of clarity, so-called branch lines are not shown, although such branch lines may be present.

[0037] Figure 1b is a schematic diagram of an example embodiment of a substrate 100. Two of the main lines of the substrate 100 are shown in more detail in Figure 1b. Main line 121 and main line 112 are shown. These main lines run across a major portion of the substrate, and may for example run across substantially the entire substrate.

[0038] As shown in FIG. 1b, multiple branches are attached to and extend from the main line. In FIG. 1b, the branches 131-134 included in the electrode 121 and the branches 141-144 included in the electrode 112 are shown. These branches are attached to the main line and extend into the area between the main lines. FIG. 1b shows one such area: the area 150 between the electrodes 121 and 112. The branches 131 and 132 of the electrode 121 and the branches 141 and 142 of the electrode 112 extend into the area 150 between the electrodes 121 and 112. Like the main lines, the branches also alternate. In particular, the branches that extend from two different electrodes into the same area alternate, for example when viewed in a first direction. In this example, the branches 142, 132, 141 and 131 belong alternately to the electrodes 112 and 121. Thus, in an embodiment, when viewed in the second direction, the main lines alternate, and when viewed in the first direction, the branch lines alternate. The branch lines are included in either the first electrode or the second electrode. Typically, the first and second electrodes, including their main lines and branch lines, are not directly electrically connected, and thus an electric field can be established between the first electrode and the second electrode, including between the main lines and branch lines.

[0039] For example, if an imaginary line is drawn in the overlap region parallel to two subsequent main lines, the imaginary line may alternately intersect with a branch line from the first main line and a branch line from the second main line, and so on.

[0040] Extending the branches from the main line has several advantages. These branches affect the diffraction of the substrate even in the case of straight main lines. On the other hand, the branches increase the risk of disturbing the homogeneity of the electric field. In particular, hot spots may be created near the tips of the branches and weak spots elsewhere. In an embodiment, at least one of two subsequent branches that extend into the same area extends at least halfway across that area. As a result, the non-transmitting state may be more homogeneous and the transitions between states may be faster and / or more homogeneous.

[0041] If the branches are perpendicular to the main lines, the point at which the branches originate on one main line is exactly opposite (when viewed in a second direction) to the point at which they originate on the adjacent main line, and therefore the branches cannot overlap. In this case, the branches originating from one main line are collinear with the branches from the opposite main line, so that, for example, when the branches are extended, they overlap with the branches from the opposite main line. In such a case, there is a risk that hot spots are created where the tips of the branches are close and weak spots are created elsewhere. This can be avoided, for example, by a suitable angle such that there is a suitable overlap. For example, this angle may depend, for example, on the line width and the line spacing.

[0042] Avoiding hot spots due to collinear, e.g. perpendicular, branches, may be avoided in embodiments by interdigitating the branches. For example, the points on the main lines where the branches originate may be offset from each other or staggered. The angle may be chosen so that the branches do not cross the next branch. Staggering may be used to avoid the branches being collinear. In embodiments, the branches are perpendicular to their main lines and staggered with the branches of the subsequent main lines. In embodiments, the branches are not non-perpendicular, staggered, or non-staggered. In embodiments, for example, the angle of the branches may be selected from a range of, for example, about 5 degrees to about 85 degrees. If the line spacing is very large, the angle may be close to perpendicular.

[0043] In FIG. 1b, a dashed line is shown halfway between the electrodes 121 and 112. The distance 151 between the electrode 121 and the midline is half the distance between the two subsequent main lines 153. This dashed line is imaginary and is not actually visible in the embodiment. In FIG. 1b, the branches 131 and 132 are shown to extend beyond the dashed line, i.e., at least halfway across the area 150. For example, one may project the branches 131 or 132 in the second direction 102 on the imaginary line 162. The length of the projected branches 131 and 132 is longer than half the distance between the electrodes 121 and 112. The branches on the opposing main lines may or may not exceed half the distance between the main lines; as shown in FIG. 1b, the branches 141 and 142 do not exceed half, but the branches 141 and 142 may be extended to pass through the midline of the dashed line.

[0044] In an embodiment, the branches form an angle with the electrodes that is significantly different from orthogonal, for example at least 5 degrees (out of 180 degrees), such as at least 5% of a right angle. Having different values ​​reduces diffraction effects.

[0045] In an embodiment, two subsequent branches that extend into the same area between a first main line and a second main line overlap in the second direction when projected in the first direction. For example, Fig. 1b shows two subsequent branches: branches 141 and 131. The area where these two branches overlap is shown in Fig. 1b by a dashed oval. When these two subsequent branches are projected in the first direction on an imaginary line 162 that extends in the second direction, branches 131 and 141 overlap in projection 161. Fig. 5a shows examples of both smaller and larger overlaps.

[0046] For example, simulations have been successfully performed for embodiments with spurs penetrating into the area by the following amounts: 60-50; 63-46; 64-45; 60-46, 65-61; 83-78; 95-95. Figure 1b shows a spur with a penetration of 80-40 and an overlap of 20 in percentage of line spacing. These numbers refer to the percentage of line spacing into which the spur penetrates. The length of the spur is measured here only along the second direction, for example after projection in the first direction. The length of the overlap in the second direction in some embodiments may be, for example: 10; 9; 9; 6; 26; 61; 95, etc. The latter is expressed as a percentage of line spacing.

[0047] In an embodiment, the distance from the tip of a branch line, e.g., branch line 131, to a subsequent main line, e.g., main line 112, is approximately equal to the distance between the branch line and the subsequent branch line, e.g., the distance between branches 131 and 141. For example, the larger of these two distances may be less than 110% of the smaller of these distances.

[0048] In an embodiment, the distance from each other of two subsequent branch lines from the same main line that extend into the same area between the first and second main lines, measured in the first direction, may be significantly less than the line spacing. For example, the branch line distance may be only 5% or less of the line spacing. However, other embodiments have a larger distance, for example 30% or more of the line spacing. For example, branch lines 131 and 132 extend into the same area between main lines 121 and 112.

[0049] Generally speaking, the beneficial effects of applying the support lines, for example, are enhanced if the support lines are applied throughout the design. For example, the support lines need not be applied to all parts of the substrate, but by doing so, the favorable effects of the support lines may be seen in all parts. However, there may be various reasons not to use support lines in some parts, such as, for example, parts where optical differences may be desired, for example to visually distinguish the parts, or parts that use different methods to avoid diffraction, such as waves.

[0050] FIG. 1c is a schematic diagram of an example of an embodiment of a support line in a substrate. FIG. 1c is drawn to scale. In substrate 171, an example is shown in which two subsequent support lines do not overlap; as shown, there is a -5% spacing. In substrate 172, an example is shown in which two subsequent support lines do not overlap but reach the same point in the area between the two main lines; as shown, there is a 0% spacing. In substrate 173, an example of an embodiment is shown in which two subsequent support lines have a 5% overlap. In substrate 174, an example of an embodiment is shown in which two subsequent support lines have a 20% overlap. Substrate 174 shows that support lines extending from both sides into the same area can extend more than half the line spacing. By overlapping the support lines, the tendency for hot spots is reduced.

[0051] Two subsequent branches of different main lines may have the same length or may have different lengths, thereby offsetting the area where the two branches overlap.

[0052] For example, in an embodiment, the longer branch line may be at least 5% longer than the shorter branch line. For example, the longer branch line may be up to 50% longer than the shorter branch line. For example, the length of the longer branch line, measured, for example, along the branch line, may be 1.05 times the length of the shorter branch line, measured, for example, along the branch line. In an embodiment, the longer branch line may be between 4% and 40% longer than the shorter branch line.

[0053] For example, in an embodiment, two subsequent branches of different main lines have the same length.

[0054] In an embodiment, the electrode includes a number of straight main lines from which branch lines extend. The main lines, also called center lines, may be parallel to each other. The distance between two branch lines is called the branch line spacing, e.g., distance 152. The distance between two main lines is the line spacing. The pitch may be 1 line spacing + 1 line width, i.e. the width of one entity that may be repeated.

[0055] For example, the distance between the points where the supports occur on the main line may be called the support spacing. This support spacing may be constant for supports that extend into the same area. Support spacing may also vary along the main line. Supports may be alternated or staggered, for example, offset by half the support spacing between them. The advantage of supports is that they allow the distance between electrodes to be homogenous, and therefore the electric field to be established between the electrodes. At the same time, diffraction effects may be reduced, for example by disrupting the repeatability of the design.

[0056] In an embodiment, the electrode lines have a width selected from the range of about 1 to 50 micrometers. The line spacing can be selected from the range of about 50 to 100,000 micrometers. For example, the line spacing can be 800 micrometers, e.g., in the range of 50-1000 micrometers, although even larger line spacings are possible. By having branch lines, it is possible to have large line spacings and still maintain a homogenous electric field. Increasing the line spacing reduces diffraction effects associated with the main lines. In an embodiment, the line spacing is at least 500 micrometers.

[0057] In an embodiment, the length of the branches may vary. For example, the lengths of the branches may alternate along a main line, or may follow a series of repeated branch lengths, etc. This has the advantage of staggering the points of maximum electric field. This is particularly beneficial for large line spacings, such as 500 micrometers. For example, the lengths of subsequent branches may differ in an embodiment, such as by as much as 60%.

[0058] In an embodiment, the main lines of the first and second electrodes are arranged alternately with respect to each other on the substrate. One way to achieve this is by forming the first and second electrodes into a comb shape, the teeth of the comb being the main lines. By interdigitating the teeth of the two combs, an interdigitated pattern is obtained. It is not necessary to use two comb shapes. For example, FIG. 1d is a schematic diagram of an example of an embodiment of a first electrode and a second electrode arranged in a pattern across the substrate. For simplicity, FIG. 1a and FIG. 1d show only the main lines and not the supporting lines. The pattern is created such that there is no direct electrical contact between the two electrodes. A minimum distance between the two electrodes may be implemented.

[0059] The design with support lines increases the number of angles on the substrate, which contributes to reducing diffraction. Furthermore, many parameters can be changed to increase this effect. For example, the length of the support lines, the support line angles, the support line distance along the main line, the line spacing, etc. can be changed. Preferably, the support lines in the same area are at least locally parallel, so that the support line angle to the right of a main line is the same as the support line angle to the left of the next main line. If the line spacing is changed, the support line distance may also change proportionally, for example depending on the line spacing; for example, a maximum electrode distance between two subsequent support lines may be maintained, for example to enforce a minimum strength in the electric field.

[0060] Fig. 2a is a schematic diagram of an example of an embodiment of a substrate 200. Four of the main lines are shown in Fig. 2a: main lines 201-204. For example, main lines 201 and 203 may be included in a first electrode, e.g. electrode 110, and main lines 202 and 204 may be included in a second electrode, e.g. electrode 120. The line spacing 251, e.g. the distance between main lines 201 and 202, is shown. Also shown are the line spacing 252 between main lines 202 and 203 and the line spacing 254 between main lines 203 and 204. In this example, the line spacing changes in the second direction. For example, the line spacing 251 is different from the line spacing 252, which is different from the line spacing 253. Changing the line spacing contributes to reducing diffraction effects.

[0061] FIG. 2b is a schematic diagram of an example of an embodiment of a substrate. Main lines 201-206 are shown. These main lines have different sections in which the line spacing can vary differently. For example, a section or region of the main lines can extend in a second direction across the substrate. In FIG. 2b, two sections are shown: section 221 and section 223. As illustrated in FIG. 2b, in section 221, the line spacing is proportional to: 11, 9, 7, 9, 11, while in section 223, the line spacing is proportional to 7, 11, 9, 9, 11. The line spacing between two subsequent main lines therefore varies in this example in the first direction as well as in the second direction. Between the first section 221 and the second section 223, there is a connection section 222 where the main lines of the two sections are connected. The line spacing in section 221 is selected according to an alternating pattern of increasing and decreasing line spacing. The line spacing in section 223 is selected randomly.

[0062] For example, in an embodiment, the line spacing alternates between increasing to a maximum distance and decreasing to a minimum distance. For example, it may be increased, e.g., by a predetermined or randomized amount, until a maximum distance is reached, after which the line spacing may be decreased in a similar manner, e.g., until a minimum line spacing is reached. Below, various strategies are given to ensure that the line spacing is changed globally.

[0063] For example, in an embodiment, the line spacing is increased by 3% until a maximum value is reached, for example up to an additional 20% compared to the initial value. i If is the line spacing, and x0 is the initial line spacing, then x i x until >1.2*x0 i+1 =x i *1.03. After that point the line spacing may decrease in the same pattern or by the same percentage or the value may be reset and the pattern begins again, etc.

[0064] For example, in an embodiment, the line spacing is alternately increased and decreased by a certain percentage of the previous value, for example, 7%. If the spacing is less than some value less than the initial value, for example, less than 10 micrometers, the spacing can be reset. For example, x i <until reaching the point of x0-10, rule x i+1 =1.07*x i and rule x i+1 =0.93*x i may be alternated. After that point, the line spacing may be decreased in the same pattern or the same percentage. These values can be modified.

[0065] Another option is to alternate the increase and decrease, but the amount depends on the difference from the initial value. For example, x i+1 =α(x i -x0) may be set. In this case too, the line spacing can be reset when the maximum or minimum value is exceeded. Values of α greater than 1 or less than 1 may alternate; for example, x i+1 =α i (x i -x0) may be used, with α i >1 used for even indices i and α i <1 used for odd indices.

[0066] Another option is to alternate high and low values of the line spacing. For example, the high values may be randomly selected from a high range and the low values may be selected from a low range. The high range and the low range may be separate or may partially overlap.

[0067] The line spacing may be changed randomly. For example, it may be completely random or random using additional criteria such as alternating large and small line spacings. For example, the odd line spacings may be derived from a probability distribution different from that of the even line spacings. In two distributions with different high and low expected values, for example, the higher expected value may be at least 10% or 20% higher than the lower expected value.

[0068] When the line spacing is randomly selected or modified, additional criteria may still be satisfied. Above, it was mentioned to enforce a maximum line spacing and a minimum line spacing. Another useful criterion that may be enforced is that the sum of the line spacings lies between a minimum and a maximum total distance. This has the advantage that the connection portion 222 remains controlled. This may be obtained by drawing from a joint distribution conditioned on the desired criteria. This may also be obtained, for example, by first selecting randomly and then modifying the random selection until the constraint is satisfied.

[0069] For example, in an embodiment, x ≦x i ≦max x and min s ≦Σx i ≦max s So, min x , max x , min s , max s If is the limit on the line spacing and the sum of the line spacings, then the line spacing x i These line spacings may be varied in a predetermined pattern, for example as suggested above, or randomly, for example drawn from one or more distributions.

[0070] The line spacing may be varied in the second direction as well as in the first direction. In this case, the variation can be controlled to control the shape of the connection. For example, FIG. 2c is a schematic diagram of an example embodiment of a substrate. Two main lines 201 and 202 are shown. At the top of FIG. 2c, there is a line spacing 231. This line spacing is varied at the bottom of FIG. 2c. The main line 201 is shown in dashed lines how it would continue if no shift occurred. The distance 232 is the distance between the main lines 201 and 202 shown in dashed lines after the shift at the bottom of the figure. By maintaining a percentage increase or decrease in the distance 232 compared to the line spacing 231 below a threshold, the connection is controlled to prevent it from becoming too abrupt, for example. For example, in an embodiment, the distance 232 is less than 1.35 times the line spacing 231. This variation in line spacing can be controlled as well. Instead of (or in addition to) controlling the size of the line gaps, the angle made by the junctions in the main lines, such as lines 201 and 202, can be controlled, e.g. the angle should be below a threshold to avoid lines becoming too steep. Another way to control this is to verify that subsequent junctions are not too close to each other.

[0071] Simulation experiments confirm that varying the line spacing is beneficial in reducing diffraction compared to constant line spacing. It has also been found that randomness in the line spacing works well in reducing diffraction effects. A gradient pattern in the line spacing can reduce diffraction, but does not work as well as a more randomized variation in line spacing. For example, diffraction is most reduced when the line spacing alternates between random low and random high values. Diffraction effects can be further suppressed by support lines.

[0072] The selection of valid electrode patterns may be performed by a computer. For example, a large number of electrode patterns may be automatically generated and for these patterns a diffraction parameter indicative of the severity of diffraction effects may be calculated. In some cases, other parameters may also be calculated, such as a homogeneity parameter indicative of the homogeneity of the electric field. From the generated electrode patterns, valid patterns may be selected based on this computer parameter.

[0073] Figure 3 is a schematic diagram of an example embodiment of a substrate 300. In Figure 3, a main line is shown built up as a series of connected sub-main lines, with branch lines extending from the main line. The main lines may, but need not, correspond to the portions described with reference to Figure 2b. For example, a portion as in Figure 2b may comprise multiple main lines.

[0074] In Fig. 3 a main line 301 is shown with two secondary main lines 322 and 312 and a connecting portion 311. The dashed boxes 320 and 310 show the secondary main lines together with several branches. Such boxes may be selected as a unit, for example they may be repeated as a unit or they may be selected from a number of units, for example randomly.

[0075] An advantage of the modular design of FIG. 3 is that many parameters of the branches can be selected simultaneously. For example, branches that extend on the same side of a minor main line may have equal lengths, and branches that extend on the same side of a minor main line may be parallel. Additionally, the number of branches extending from each side of a minor main line may be equal. These selections facilitate more effective design selections because fewer parameters need to be controlled. For example, a minor main line and its branches selected at one location may be repeated at other locations.

[0076] On the other hand, the design of FIG. 3 still allows for significant variations. For example, the branches extending on the same side of a minor main line and the branches extending from subsequent minor main lines of the same main line may have different lengths and may form different angles with the first direction. Both options are shown in FIG. 3. Different minor main lines may also have different numbers of branches extending from the sides of the minor main line; this is not shown in FIG. 3. The angles that the branches of the main line or the minor main line make with the first direction may be randomly selected between a minimum and a maximum angle, such as between 45 degrees and 90 degrees. It should be noted here that the minor main line 322 and the minor main line 312 are shifted relative to each other in both the first and second directions. Fixing some parameters within the dashed box significantly reduces the selection effort without significantly affecting the achievable results.

[0077] In an embodiment, the line width may be selected from the range of about 1-50 micrometers. The line spacing may be selected from the range of about 40-100000 micrometers. The length of the minor main lines, for example in FIG. 3, or of the portion, for example in FIG. 2b, may be related to the line spacing. For example, their length, measured, for example, in a first direction, may be selected between 5 and 10 times the line spacing. In general, different values ​​are possible, but these choices have been found to be efficient. Although FIG. 2a-FIG. 2c do not show branch lines, branch lines may be present as in the embodiment. The number of branch lines in the minor main lines or portions may be changed as well, for example from 3 to 10.

[0078] Varying the line spacing without support lines also reduces diffraction effects, but a combination of these options is better. In fact, it is possible to create a substrate without using support lines. An example of such a substrate is a substrate (100) used in smart glazing, where a first electrode (110) and a second electrode (120) are applied to the same side of the substrate, where each of the first and second electrodes is arranged in a pattern across the substrate, where each of the first and second electrodes comprises a first and second plurality of main lines (111-113, 121-123) extending in a first direction (101) across the substrate, where the first and second plurality of main lines of the first and second electrodes are arranged alternately with respect to each other on the substrate, where the distance between the main lines (201, 202, 203) and adjacent or subsequent main lines (202, 203, 204) on the substrate of the first electrodes (201, 203) and the second electrodes (202, 204) varies in the second direction and / or in the first direction. This substrate reduces diffraction due to the variation in line spacing. The substrate may be combined with the features described herein, particularly those relating to varying line spacing.

[0079] Most figures show main lines that are straight main lines or a combination of straight secondary main lines. However, this is not necessary. For example, the main lines may be wavy, for example sinusoidal, as shown for example in PCT / EP2020 / 052379. FIG. 4a shows a schematic example of a substrate with multiple main lines, but the main lines are wavy. The main lines are connected to two or more electrodes, for example as shown in FIG. 1a or FIG. 1d. The example of FIG. 4a does not include branch lines, but branch lines can be incorporated with wavy main lines as well. In this situation, controlling the position, angle and length of the branch lines is a big problem since the distance between the main lines is not fixed along the line. The improved ability to change the design allows for a further reduction in diffraction. FIG. 4b shows a schematic pattern of a substrate in which the branch lines are combined with non-straight main lines, for example wavy main lines. The branch lines do not have to be straight either.

[0080] The use of wavy main lines may increase uniformity and reduce hot spots without overlapping support lines. An example of such a substrate is a substrate (100) used in smart glazing, in which a first electrode (110) and a second electrode (120) are applied to the same side of the substrate, each of the first and second electrodes is arranged in a pattern across the substrate, each of the first and second electrodes comprises a plurality of main lines (111-113, 121-123) extending in a first direction (101) across the substrate, and the first and second electrodes are ... The multiple main lines of the two electrodes are arranged alternately with respect to each other on the substrate, multiple branch lines (131-134, 141-144) extend from the main lines into the areas between the main lines, branch lines (142, 132, 141, 131) extend alternately from the first and second main lines into the area (150) between the first main line (121) and the second main line (112) of the first and second electrodes, and one or more, or all, of the main lines are wavy.

[0081] Fig. 4c is a schematic diagram of an example of an embodiment of a substrate 450, in which the pattern in which the first and second electrodes are arranged is subdivided into a set of blocks extending across the substrate in a first and second direction. These blocks contain parts of the electrode pattern, and thus larger patterns are made up by combining the blocks. For example, each block may comprise a number of minor lines of a portion of the main lines of the first electrode and a number of minor lines of a portion of the main lines of the second electrode. The sides of the blocks may be, for example, between 1 mm and 10 mm. For example, the blocks may be 8 mm x 8 mm.

[0082] The blocks may be arranged in some regular pattern, for example a checkerboard pattern, but irregular patterns are also possible, for example as shown in Fig. 4c. The blocks may also be rectangular. An advantage of using blocks is that beneficial blocks, for example having particularly low diffraction effects and / or particularly good electric field homogeneity, can be repeated several times on the substrate.

[0083] One or more of the blocks include a pattern according to an embodiment, but some blocks may include other patterns as well, such as a pattern without branches, such as the pattern shown in Figure 4a. Some of the main lines in the blocks may be straight, some may be wavy, some may have branches, some may not, etc.

[0084] Interestingly, working with line shapes at a micro level, as shown for example in various examples herein, may affect parameters such as diffraction and homogeneity, but may still have significant optical effects, potentially hindering the geometry of designs at larger scales. It is therefore possible to combine different electrode shapes that are made as blocks at different levels. In terms of block structure, blocks can be created at different levels, e.g., different levels of randomization, with increasing pattern size. In practice, it is convenient, but not necessary, for the number of lines in a block to be a multiple of two.

[0085] In an embodiment, the electrodes are driven with an electrical circuit supporting a limited number of voltage sources, for example four voltage sources. In an embodiment, the number of voltage sources is equal to the number of electrodes, which may be more than two on a given substrate. In an embodiment, the lines on the substrate are divided across more than two electrodes, or even more than four electrodes, or even more. It is preferred that the number of main lines per electrode is approximately equal. For example, in an embodiment, a plurality of segments are arranged on the substrate, each segment being controlled by at least two electrodes for the substrate and at least four electrodes in an assembly of at least two substrates. By driving corresponding electrodes, different optical effects can be configured on different segments. Although possible, the fluid does not have to be constrained to one segment. If the segments are separated from each other, different fluids can be provided to them.

[0086] 5a is a schematic diagram of several examples of embodiments of substrates with electrode patterns, according to an embodiment. The embodiments shown in FIG. 5a are all to scale and can be expanded to all electrode patterns, for example the following interdigitated patterns:

[0087] Figure 5b shows a schematic example of an embodiment of a substrate configured for two or three electrodes. The left of Figure 5b shows that the main lines marked with the letters "a" and "b" belong to the same electrode. All lines marked with "a" are electrically connected, but this is not shown in the details of the electrode pattern shown in Figure 5a or 5b; similarly for the main line "b". The right of Figure 5b shows that the main lines marked with the letters "a", "b" and "c" belong to the same electrode. All lines marked with the same letter are electrically connected.

[0088] Figures 6a and 6b show a schematic comparison of two substrates, and Figures 6c-d show two examples of the embodiment. Diffraction patterns were simulated. Simulating diffraction patterns is per se known in the art.

[0089] The diffraction level was calculated according to the method described in "Numerical comparison of grid pattern diffraction effects through measurement and modeling with OptiScan software", Murray et al., published May 20, 2011, SPIE journal (doi: 10.1117 / 12.883422). This method consists of calculating the power spectrum of an image representing the electrode pattern, where the electrodes are drawn in black on a white background. From this raw power spectrum, the diffraction level is calculated as the ratio of the maximum intensity of the higher diffraction orders divided by the intensity of the zeroth diffraction order.

[0090] [Table 1]

[0091] FIG. 6a shows, on the left, a simple pattern consisting of only linear main lines. These main lines are connected together at an electrode, for example at two electrodes in an interdigitated pattern. The pattern in FIG. 6b has additional straight lines that are orthogonal. Note that rotating this pattern does not help, since it only rotates the diffraction pattern. FIG. 6c and FIG. 6d are schematic diagrams of examples of substrate embodiments. FIG. 6c uses varying line spacing and varying angles, as well as shifting minor main lines. FIG. 6d uses a higher density of block changes along the lines, i.e., a higher number of vertical blocks. FIG. 6c shows three blocks, with the main line changing direction three times. FIG. 6d has ten blocks, with the main line changing direction ten times. Note that the maximum diffraction values ​​for values ​​6c and 6d are significantly lower than for linear designs such as FIG. 6a and FIG. 6b.

[0092] Not only does the pattern in Figure 6b have undesirable diffraction values, but it also tends to have hot spots between the opposing supports: the electric field is much higher in the regions between the tips of the opposing supports than elsewhere, resulting in a non-uniform appearance and non-uniform transition speeds to the opaque state.

[0093] The wavy line design of Figure 4a gives similar values ​​as the design of Figure 6c, but the design with the support lines was found to be quicker and easier to make useful selections for. Furthermore, the design with the support lines provides a more homogeneous electric field than the wavy line design.

[0094] Two substrates according to the embodiments can be bonded to form a light modulator, which is particularly suitable for glazing. Exemplary embodiments of the light modulator are given below.

[0095] FIG. 7a illustrates a schematic diagram of an embodiment of a light modulator 10 that may be applied in smart glazing.

[0096] Reference is made to patent application PCT / EP2020 / 052379, which is incorporated herein by reference; this application includes useful designs for optical modulators, which may be further improved, for example, by including electrodes and / or supports as described herein.

[0097] The light modulator 10 can be electronically switched between a transmissive state and a non-transmissive state and vice versa, or between a reflective state and a non-reflective state and vice versa. The light modulator 10 comprises a first substrate 11 and a second substrate 12 arranged opposite each other. On the inner side of the first substrate 11, at least two electrodes are applied; electrodes 13a, 13b are shown. These at least two electrodes are collectively called electrodes 13. On the inner side of the second substrate 12, at least two electrodes are applied; electrodes 14a, 14b are shown. These at least two electrodes are collectively called electrodes 14.

[0098] A fluid 15 is provided between the substrates. The fluid contains particles 30, e.g. nanoparticles and / or microparticles, which are charged or can be charged. For example, the particles may inherently carry a charge on their surface. For example, the particles may be surrounded by charged molecules.

[0099] The electrodes are configured to drive the particles 30 to move towards or away from the electrodes in response to an applied electric field. The optical properties, in particular the transmittance or reflectance of the light modulator, depend on the location of the particles 30 in the fluid. For example, connections may be made to apply an electromagnetic field to the electrodes.

[0100] In one example, the substrates 11 and 12 may be optically transparent outside the electrodes, typically >95% transparent, for example >99% transparent at the wavelengths of interest. Taking into account the electrodes, the transmittance may be much lower, for example 70%. The term "optical" may relate to wavelengths visible by the human eye (about 380 nm-about 750 nm), if applicable, and may relate to a broader range of wavelengths including infrared (about 750 nm-1 μm) and ultraviolet (about 10 nm-380 nm), and sub-selections thereof, if applicable. In an exemplary embodiment of the optical modulator, the substrate material is selected from glass and polymer.

[0101] In another example, one substrate, such as the lower substrate 12, may be reflective or partially reflective, while the upper substrate 11 is transmissive. The optical properties, in particular the reflectivity of the light modulator, depend on the location of the particles 30 in the fluid. When the panel is in the open state (vertical actuation), the particles are mostly located between the opposing electrodes of the two substrates, such that incident light can pass relatively unhindered through the transmissive upper substrate and optical layer and be reflected or partially reflected on the lower substrate.

[0102] The distance between the first and second substrates is typically less than 30 μm, such as 15 μm. In an exemplary embodiment of the optical modulator, the distance between the first and second substrates is less than 500 μm, preferably less than 200 μm, preferably less than 100 μm, and even more preferably less than 50 μm, such as less than 30 μm.

[0103] In one example, the modulator may be provided in a flexible polymer and the remainder of the device may be provided in glass. The glass may be hard glass or flexible glass. If necessary, a protective layer may be provided on the substrate. If more than one color is provided, more than one layer of flexible polymer may be provided. The polymer may be polyethylene naphthalate (PEN), polyethylene terephthalate (PET) (optionally with a SiN layer), polyethylene (PE), etc. In a further example, the device may be provided in at least one flexible polymer. Thus, the modulator may be attached to any surface, such as using an adhesive.

[0104] The particles 30 may be configured to absorb light, thereby preventing certain wavelengths from passing through. The particles 30 may reflect light; for example, this reflection may be specular, diffuse, or something in between. The particles may absorb some wavelengths and reflect others. The particles may also, or alternatively, emit light, for example, using phosphorescence, fluorescence, or the like. The fluid may also emit light, but its emissivity is modulated by changing the location of the particles.

[0105] In an exemplary embodiment of the light modulator, the nanoparticles have a size of 20-1000 nm, preferably 20-300 nm, and more preferably less than 200 nm. In an exemplary embodiment of the light modulator, the nanoparticles / microparticles may include a coating on a dye, and preferably include a core. In an exemplary embodiment of the light modulator, the coating of the particle is formed from a material selected from a conductive material and a semiconductive material.

[0106] In exemplary embodiments of the optical modulator, the particles are configured to absorb light having wavelengths between 10 nm-1 mm, such as 400-800 nm, 700 nm-1 μm, and 10-400 nm, and / or to absorb a portion of light having a wavelength range within 10 nm-1 mm (filter), as well as combinations thereof.

[0107] In an exemplary embodiment of the light modulator, the particles are charged or chargeable. For example, the charge on the particles is between 0.1e and 10e (5*10) per particle. -7 -0.1C / m2) in some cases.

[0108] In an exemplary embodiment of the light modulator, the fluid is present in an amount of 1-1000g / m2, preferably 2-75g / m2, more preferably 20-50g / m2, such as 30-40g / m2. With this layout, a major advantage is that very little fluid and therefore very few particles can be used.

[0109] In an exemplary embodiment of the light modulator, the particles are present in an amount of 0.01-70 g / m2, preferably 0.02-10 g / m2, such as 0.1-3 g / m2.

[0110] In an exemplary embodiment of the light modulator, the particles have a color selected from cyan, magenta, and yellow, black and white, and combinations thereof.

[0111] In an exemplary embodiment of the light modulator, the fluid includes one or more of a surfactant, an emulsifier, a polar compound, and a compound capable of forming hydrogen bonds.

[0112] Fluid 15 may be a non-polar fluid having a relative dielectric constant of less than 15. In an exemplary embodiment of the light modulator, the fluid has a relative dielectric constant εr of less than 10, such as less than 100, preferably less than 5. In an exemplary embodiment of the light modulator, fluid 15 has a kinematic viscosity of greater than 10 mPa.s.

[0113] The electrodes 13a, 13b and electrodes 14a, 14b are in fluid contact with a fluid. The fluid may be in direct or indirect contact with the electrodes, for example the fluid may contact the second medium with the electrodes, such as through a porous layer. In an embodiment, the electrodes cover about 1-30% of the substrate surface. In an embodiment, the electrodes comprise a conductive material with a resistivity of less than 100 nΩm (at 273K; for comparison, the ITO used typically has 105 nΩm), which has a conductivity >1*10 at 20°C.7 S / m). In embodiments of the light modulator, the electrodes include copper, silver, gold, aluminum, graphene, titanium, indium, and combinations thereof, and preferably copper. The electrodes may be in the form of fine wires embedded in a polymer-based substrate; for example, in the form of copper fine wires.

[0114] In connection for applying an electromagnetic field to the electrodes, the applied electromagnetic field to the electrodes results in the movement of nanoparticles and microparticles from the first electrode to the second electrode and vice versa. Connection for applying an electromagnetic field to the electrodes may be provided. For example, in an exemplary embodiment of the light modulator, the current is between -100-+100 μA, preferably between -30-+30 μA, more preferably between -25-+25 μA. For example, a power provider may be in electrical connection with at least two electrodes. The power provider may be configured to provide a waveform power. At least one of the amplitude, frequency, and phase may be configurable to result in different states in the light modulator. For example, the aspect of the power may be configured by a controller.

[0115] The light modulator 10 may include one or more segments, where a segment is a single optically switchable entity that may vary in size. The substrate at least partially encloses a volume that may be a segment.

[0116] The device may include a driving circuit for modifying the appearance of the (individual) segments by applying an electromagnetic field. Thus, the appearance of the light modulator, or one or more parts thereof, may also be modified. For example, the segments may be at least 1 mm 2 The design allows for stacking to allow for more colors; for example, for a full-color application, a stack of two or three modulators could each provide most or all of the colors.

[0117] Having one or more segments allows the light modulator to be locally controllable; this is beneficial in some applications but is not required. For smart glazing, the light modulator can be used with or without segments. For example, when applied in smart glazing, the transmittance or reflectance can be locally controlled, for example to block sun-patches without reducing the transmittance or reflectance in the entire window. The segments may be relatively large, for example having a diameter of at least 1 mm, or at least 1 cm.

[0118] In an exemplary embodiment of the light 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 to face each other. With aligned substrates, the electrodes on different substrates are behind each other when viewed perpendicular to the substrates. When the light modulator is removed and both substrates are positioned with the electrodes facing up, the electrode patterns are mirror images of each other.

[0119] While aligning the substrates may increase the maximum transmittance or reflectance of the optical modulator, it may be better not to align the two substrates or not to align them completely when selecting an optical modulator for more criteria than a range, such as transmittance or reflectance. The optical modulators can be stacked. For example, two stacked optical modulators can be formed from three substrates, with the middle substrate having electrodes on both sides. In the optical modulator embodiment, optionally, at least one substrate 11, 12 of the first optical modulator is identical to the substrate 11, 12 of the at least one second optical modulator. Also, in the case of stacked modulators, alignment may increase the maximum transmittance or reflectance, but may be detrimental to other considerations, such as diffraction.

[0120] FIG. 7b is a schematic diagram of an example embodiment of a light modulator 40. The light modulator 40 is similar to the light modulator 10, except that it includes multiple optical layers, as shown in the example with two optical layers. There may be more than two optical layers. Each optical layer is disposed between two substrates. The light modulator 40 may be considered as a stack of two-substrate light modulators as in FIG. 7a. As shown, the light modulator 40 includes three substrates: a first substrate 41, a second substrate 42, and a third substrate 43. Between the substrates 41 and 42 there is an optical layer, and between the substrates 42 and 43 there is an optical layer. These optical layers may be similar to those in the light modulator 10. The controller 46 is configured to control the current on the electrodes of the substrates. For example, in FIG. 7b, the controller 46 may be electrically connected to at least 4×2=8 electrodes.

[0121] Interestingly, the particles in multiple optical layers can be different, and thus multiple layers can be used to control more optical properties of the light modulator. For example, the particles in different optical layers can absorb or reflect at different wavelengths, e.g., have different colors. This can be used to create different colors and / or different color intensities on the panel of the controller 46. For example, a four-substrate panel can have three optical layers with different color particles, e.g., cyan, yellow, and magenta particles, respectively. By controlling the transmittance or reflectance of those different colors, a wide spectrum of colors can be created.

[0122] The surface of a substrate facing another substrate may have more than one pattern, for example in an embodiment, for example the outer substrates 41 and 43 may receive electrodes only on the inside, while the inner substrates, for example substrate 42, may have electrodes on both sides.

[0123] Substrates 41 and 42 may both be considered as embodiments of an optical modulator. Similarly, substrates 42 and 43 may both be considered as embodiments of an optical modulator.

[0124] FIG. 7c is a schematic diagram of an example embodiment of a car 20 having smart glazing for the window 21. This is a particularly beneficial embodiment since the level of incident light may change frequently and rapidly during driving. The use of smart glazing in a car has the advantage that the light level may be maintained at a constant level by adjusting the transmittance of the car window. Furthermore, the reduction of diffraction effects improves safety since it reduces driver distraction. The car 20 may include a controller configured to control the transmittance or reflectance of the window 21.

[0125] Smart glazing can also be used in other applications of glazing, particularly where the amount of incoming light is variable, such as in buildings, offices, homes, greenhouses, skylights, etc. Skylights are windows placed in the ceiling to allow sunlight to enter a room.

[0126] 8a-b show schematic side views of an embodiment when using a light modulator. Applying an electric field to the electrodes on the substrate generates an electric force on the particles. Using this effect, the particles can move around and thus induce different transmission or reflection states in the light modulator. A controller can control the electric field, such as its amplitude, frequency, and phase. In an embodiment, the controller is connected to at least four electrodes: two electrodes per substrate. However, more electrodes may be used and connected to the controller; for example, more than two electrodes per substrate may be used to better fine-tune the gray scale and drive to non-transmission or non-reflection states. Multiple electrodes may also be used to support multiple segments on the substrate.

[0127] Figure 8a shows the light modulator with no electric field applied, in which no electric force is yet applied to a particle 30 suspended in a fluid 15.

[0128] In the configuration shown in Figure 8a, the conductive electrode pattern disposed on the upper substrate is perfectly aligned or nearly 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, etc.

[0129] Alignment between the top and bottom electrode patterns contributes to a wider range of achievable levels of transmittance or reflectance, although alignment is not necessary as a similar effect can be achieved without alignment. A similar range of transmittance or reflectance can be achieved without alignment.

[0130] It should be noted that in these examples, the top and bottom substrates are referred to to refer to the substrate above or below on the page, and in glazing applications the substrates may be aligned vertically rather than horizontally, so the same substrates may be referred to as, for example, a front substrate and a back substrate.

[0131] FIG. 8b shows an optical modulator, for example at instance P1, where a potential +V1 is applied to each fine-wire electrode on the top substrate, while a negative voltage, for example -V1, is applied to each fine-wire electrode on the bottom substrate. Thereby, in this case, the same positive potential is applied to all electrodes 13, and the same negative potential is applied to electrode 14. This potential difference causes negatively charged particles to flow near the electrode on the top substrate, where they approximately align with the top electrode. As a result, if both the top and bottom substrates are transparent, the transmittance of the optical modulator 10 increases. Similarly, if, for example, the top substrate is transparent and the bottom substrate is reflective, the reflectance of the optical modulator 10 increases. If the solution contains positively charged particles, the positively charged particles will flow near the electrode on the bottom substrate, where they approximately align with the bottom electrode.

[0132] In a second instance P2 in the ON state, in contrast to instance P1, the voltages of the upper and lower electrodes are reversed to achieve a similar transmittance or reflectance. In instance P2, the voltages of the electrodes on the upper substrate then provide a negative potential −V1, and the voltages of the aligned electrodes of the lower substrate provide a positive potential. This state is similar to that shown in FIG. 8b, but the upper and lower substrates are reversed. This configuration also results in a high transmittance or reflectance of the optical modulator 10.

[0133] Interestingly, the transmittance or reflectance can be maintained while reducing corrosion damage to the electrodes by switching between a positive potential on the electrode of the top substrate, e.g., shown as electrode 13 in Figure 8b (and a negative potential on electrode 14), and a positive potential on the electrode of the bottom substrate, e.g., shown as electrode 14 in Figure 8b. This AC electric field can be achieved by applying an AC potential to the top and bottom electrodes.

[0134] Applying the waveform is optional, but is an effective means of increasing the lifetime of the optical modulator by reducing corrosion. Corrosion can occur, for example, when using copper electrodes, because copper ions dissolve in the ionic fluid in one substrate and flow to the electrode of the opposing substrate, where they are deposited. By applying the waveform, the copper ion transport direction is frequently reversed, thus reducing corrosion damage. When the corrosion current between the two substrates is balanced, or nearly, e.g., >95%, balanced between the two instances P1 and P2, e.g., the corrosion rate of the electrode of the top plate occurs, and there is a balanced deposition of copper at the bottom electrode during each time instance P1, and vice versa at instance P2. Thus, there is a continuous transition or migration of particles between the top and bottom electrodes, and the optical modulator or smart window is always in an ON state, while the dynamic electrolytic current between the top and bottom electrodes is constant, and therefore there is no or negligible net loss of electrode material on the top and bottom substrates.

[0135] FIG. 8c shows how a reduced transmittance or reflectance state can be obtained. On the same substrate, an alternating voltage is applied. For example, in an embodiment, a potential +V2 is applied to a first electrode, the next immediately adjacent electrode has an opposite potential -V2, etc., as shown in FIG. 8c. This can be obtained by applying a potential +V2 to electrode 13a and an opposite potential -V2 to electrode 13b. On the opposing substrate, a potential +V2 may be applied to electrode 14a and an opposite potential -V2 may be applied to electrode 14b. For example, the electrodes may be arranged such that the electrodes on the substrate are aligned; an electrode on the upper substrate has an opposing electrode on the lower substrate, and vice versa. For example, to reduce the transmittance or reflectance, the opposing electrodes may receive the same potential, while the adjacent electrodes receive opposite potentials. An embodiment is shown in FIG. 8c, in which four electrodes are designated by references 13a, 13b, 14a, and 14b, with the rest of the electrodes alternating in sequence.

[0136] By using this AC drive cycle between the top and bottom substrates, diagonal and lateral electric fields are generated between the two substrates, which causes accidental diffusion of particles, thereby creating the closed state of the light modulator. As a result of this configuration, particles migrate diagonally and laterally between the top and bottom substrates, and the diffusion of particles into the visible aperture of the light modulator contributes to the closed, opaque state of the light modulator.

[0137] For the transmission state shown in Figure 8b, a waveform may be applied to the electrodes such that, for example, the electrodes shown in Figure 8b with a positive potential become negative, and vice versa. Applying a waveform, for example, between electrodes 13a and 13b and between electrodes 14a and 14b as in Figure 8b, reduces corrosion damage to the electrodes.

[0138] An AC drive cycle can be implemented by using interdigitated wire configurations that combine the top and bottom electrode configurations shown in plan views such as Figures 5, 6a-6d.

[0139] The extent to which the transmittance or reflectance in Fig. 8b and Fig. 8c increases or decreases depends on the voltage and frequency difference. By varying the voltage difference, the amount by which the transmittance or reflectance increases and decreases, respectively, is controlled. For example, a curve representing the light transmittance versus voltage may be determined, e.g. measured. To obtain a particular level of light transmittance, e.g. to obtain a particular transmittance, e.g. a particular grayscale level, a corresponding voltage, e.g. an AC voltage, may be applied. By interpolating the signals of the transmitting or non-transmitting state, a level between transmitting and non-transmitting may be obtained. Similarly, a curve representing the light reflectance versus voltage may be determined, e.g. measured. To obtain a particular level of reflectance, a corresponding voltage, e.g. an AC voltage, may be applied. By interpolating the signals of the reflecting or non-reflecting state, a level between reflecting and non-reflecting may be obtained.

[0140] Different electrode patterns may be used for the light modulator. Each electrode pattern may provide a range of grayscales, e.g., levels of transparency or reflectivity, that the light modulator can obtain. However, the specific range of grayscales for any particular electrode pattern may differ from other electrode patterns. That is, different patterns may provide increased transparency or reflectivity or increased opacity, but the exact response to the drive signal depends on many factors, including the particular pattern used. The changes in the optical properties of the light modulator may have a fine resolution, e.g., less than 1 mm. It should be noted that pixilation of the light modulator is not required to achieve different optical patterns, e.g., logos visible on the light modulator.

[0141] This effect can be used to embed a visible image in a light modulator by locally modifying the electrode pattern on the substrate of the light modulator. For example, one may have locally gray scales with a permanent offset of the gray scale with respect to each other due to different electrode patterns. For example, by locally modifying the electrode pattern or its pitch, the maximum transmittance or reflectance can be modified.

[0142] This results in an area on the light modulator having different intensities of greyscale, e.g. different greyscales, or different intensities of colouration. However, this area may have the same colour point. In an embodiment, it may switch with the rest of the window, albeit at different rates. For example, even if the same voltage is applied to the electrodes in two different areas, it will produce different transmission states, e.g. different transmittance levels, due to different electrode patterns. For example, the curve representing transmittance versus voltage may be shifted. For example, if the voltage control is changed in the same way in both areas, the light transmittance may change in both areas, but by different amounts. Areas may also be made less responsive to drive signals by reducing the density of electrodes; in particular, areas may be made not to switch at all, e.g. by not applying electrodes in the area.

[0143] This effect can be used to embed a logo in the light modulator. For example, FIG. 9a is a schematic diagram of an example of a logo and grid embodiment. As shown in FIG. 9a, a first set of grid squares intersects the logo, and a second set of grid squares does not intersect the logo. For the first set that intersects, a different electrode pattern can be used than for the second set of grid squares. FIG. 9b is a schematic diagram of an example of a substrate embodiment. In the area indicated by the first grid square, a different electrode pattern than the area indicated by the second grid square may be embedded in the first and second substrates, such as the substrate in FIG. 7a. As shown in FIG. 9b, the two areas have different transmittances.

[0144] 9c-9d are schematic diagrams showing examples of embodiments of light modulators. In FIG. 9c, the substrate is shown in a non-transmitting configuration, and in the area indicated by the logo, the electrode pattern is shown configured to achieve a low efficiency darkening of the light modulator. In FIG. 9d, the same substrate is shown in a more transmissive configuration. It should be noted that the transmittance is increased in both the logo area and the non-logo area, albeit at different rates. The area indicated by the logo is still visible in FIG. 9d, even though the transmittance of those areas is now close to each other.

[0145] Interestingly, this effect may only be achieved by different patterning, e.g., by changing the pitch and / or design of the electrodes. No change in waveform / current / voltage / power is required to this area compared to other areas.

[0146] Embedding images into light modulators, especially in smart glazing, has many applications. For example, content such as logos, brands, etc. may be embedded. Textures may be embedded into the glazing. Contrast gradients may be embedded into the glazing. Other options include emergency exit signals such as arrows, etc.

[0147] For example, in a shop / restaurant window: a completely black window may indicate that the shop is closed, while a logo or any other designated design is visible when the shop is open. This pattern may be a logo or the like, but this is not required. The embedded image may be a pattern that prevents passers-by from seeing inside the window, while still providing sufficient light inside. In particular, the embedded image does not have to contain a readable message. In a car window, when the car is switched to the OFF state, e.g. parked, the glazing may be completely dark, while when the car is switched to the ON state, a logo appears, e.g. the manufacturer's logo.

[0148] By adjusting the design parameters, a constant local optical difference is visible compared to the background without any change in the electrical driving force. The parameters of the electrode pattern that affect the optical performance are: - Electrode Line Spacing - Electrode Wire Thickness - Electrode wire shape - Electrode line direction - Local changes in the cell gap, e.g. the distance between the substrates - Distribution of branch line lengths Includes.

[0149] For example, electrode line spacing, thickness, shape, orientation affect the local transmittance level and response time; electrode line spacing / width locally affects the diffraction level, which may also allow for specific local optical differences. Changing the cell gap changes the dark state level and, as a result, the maximum transmittance or reflectance and response time. Another option is to vary the diffraction effect between two areas. For example, one area, e.g., most of the glazing, may have an electrode pattern with low diffraction effect, while the embedded image may have an electrode pattern with deliberate high diffraction effect.

[0150] The optical performance, including the transmittance or reflectance, can also be modified by changing the electrode material; for example, by choosing an electrode material with different optical and / or conductive properties. The electrode material can affect the diffusion, reflection, and diffraction of light, which can lead to additional optical effects. The conductivity of the electrode material, when locally modified, affects the electric potential at this location and thus the electric field and, consequently, the transmittance or reflectance level.

[0151] For example, the electrode material can be copper, aluminum, gold, indium tin oxide (ITO), etc. Cu / Al is reflective, while ITO is transparent, so different electrode materials can be used to obtain different appearances regardless of voltage drive. Similarly, different materials with different resistances will produce different electric fields. For example, ITO has a smaller electric field even when driven with the same voltage.

[0152] Another way to obtain a change in transmittance or reflectance is by locally varying the spacers that can be applied between the first and second substrates. For example, different spacers can have different optical properties and densities. For example, spacers with different transmittances, different sizes can be used. The density of the spacers can be different. In an embodiment, the density of the spacers can be increased by a factor of 1000 or even more, giving a significantly different appearance. Increases of less than a factor of 1000 are also possible. Spacers can also be configured to purposefully change the distance between the substrates and thus change their appearance.

[0153] The various options for locally varying the appearance of an area of ​​the light modulator without changing the drive in that area may be applied to light modulators with a single layer, e.g. one fluidic layer, e.g. two substrates; but also to multi-layer light modulators with multiple fluidic layers and more than two substrates, the latter of which may be used to generate multiple colors.

[0154] The pattern in which the first and second electrodes are arranged is subdivided into a number of parts. There may be two parts, each with different optical properties, for example due to different electrode patterns; there may be a number of parts. For example, this may be used to apply images with multiple levels of gray, rather than only black and white.

[0155] It is not necessary to use the substrate according to the embodiment to embed the logo. For example, a useful substrate that can be used in smart glazing comprises a first electrode and a second electrode applied to the same side of the substrate. Each of the first and second electrodes is arranged in a pattern across the substrate, the first electrode and the second electrode each comprising a plurality of main lines extending in a first direction across the substrate, and the plurality of main lines of the first and second electrodes are arranged alternately with respect to each other on the substrate. The pattern in which the first and second electrodes are arranged is subdivided into a plurality of portions, and at least one of the electrode line spacing, electrode line thickness, electrode material, electrode line shape, and electrode line direction is different in the plurality of portions to produce different maximum transmittance or reflectance, or color saturation.

[0156] Substrates with such embedded logos, with or without support lines, or light modulators including such substrates, may be combined with other features described herein.

[0157] 10 is a diagram that illustrates a schematic example of an embodiment of a method for controlling an optical modulator according to an embodiment. The method 500 may be implemented by a computer. The method 500 includes: - selecting (510) one of a plurality of maximum amplitudes of an alternating current corresponding to one of a plurality of levels of transparency in the light modulator; - applying (520) an alternating current to the electrodes to obtain an electromagnetic field between the electrodes, which results in electrophoretic movement of the particles towards or away from the electrodes.

[0158] As will be apparent to one skilled in the art, many different ways of performing the method are possible. For example, although the order of steps may be performed in the order shown, the order of steps may be changed and some steps may be performed in parallel. Furthermore, other method steps may be inserted between steps. The inserted steps may represent improvements to the method as described herein or may be unrelated to the method. For example, some steps may be performed at least partially in parallel. Furthermore, a given step may not be completely finished before the next step is started.

[0159] Driving the electrodes may use a signal having a selected maximum amplitude that corresponds to one of a plurality of levels of transparency or reflectivity in the light modulator, which signal may be an alternating current or an alternating voltage.

[0160] The method embodiments may be performed using software, including instructions for causing a processor system to perform the method 500. The software may include only those steps performed by a particular subentity of the system. The software may be stored on a suitable storage medium, such as a hard disk, floppy, memory, optical disk, etc. The software may be transmitted as a signal along wires, wirelessly, or using a data network, e.g., the Internet. The software may be made available for download and / or for remote use on a server. The method embodiments may be performed using a bitstream configured to configure a programmable logic, e.g., a field programmable gate array (FPGA), to perform the method.

[0161] It will be understood that the subject matter of the present disclosure also extends to computer programs, particularly computer programs on or in a carrier configured for putting the subject matter of the present disclosure into practice. The programs may be object code, such as source code, object code, code intermediate sources, and partially compiled forms, or any other form suitable for use in implementing the embodiments of the present method. An embodiment relating to a computer program product includes computer-executable instructions corresponding to each of the processing steps of at least one of the methods described. These instructions may be subdivided into subroutines and / or stored in one or more files that may be statically or dynamically linked. Other embodiments relating to a computer program product include computer-executable instructions corresponding to each of at least one device, unit, and / or part of the systems and / or products described.

[0162] FIG. 11a illustrates a computer readable medium 1000 having a writable portion 1010 including a computer program 1020, which includes instructions for causing a processor system to perform a light modulator method according to an embodiment. For example, the processor system may be connected to a light modulator panel. The computer program 1020 may be embodied on the computer readable medium 1000 as a physical mark or by magnetization of the computer readable medium 1000. However, any other suitable embodiment is contemplated as well. Furthermore, although the computer readable medium 1000 is illustrated here as an optical disk, it will be appreciated that the computer readable medium 1000 may be any suitable computer readable medium, such as a hard disk, a solid state memory, a flash memory, etc., and may be non-recordable or recordable. The computer program 1020 includes instructions for causing a processor system to perform said light modulator method.

[0163] FIG. 11b is a schematic representation 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 the one or more integrated circuits 1110 is shown in FIG. 11b. The circuit 1110 comprises a processing unit 1120, e.g., a CPU, for executing the method according to the embodiment and / or running computer program components implementing the modules or units thereof. The circuit 1110 comprises a memory 1122 for storing programming code, data, etc. A portion of the memory 1122 may be read-only. The circuit 1110 may include a communication element 1126, e.g., an antenna, a connector, or both. The circuit 1110 may comprise a dedicated integrated circuit 1124 for performing some or all of the processing defined in the method. The processor 1120, the memory 1122, the dedicated IC 1124, and the communication element 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.

[0164] For example, in an embodiment, the processor system 1140, e.g., the device, may comprise a processor circuit and a memory circuit, where the processor is 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 a non-volatile memory, e.g., a flash memory. The memory circuit may be a volatile memory, e.g., an SRAM memory. In the latter case, the device may comprise a non-volatile software interface, e.g., a hard drive, a network interface, etc., configured to provide the software.

[0165] For example, a controller for a light modulator that controls the voltages applied to the electrodes may comprise a processor circuit, or alternatively, may also comprise a state machine.

[0166] 12-37 are schematic diagrams showing examples of embodiments of light modulators. In these figures, voltages that can be applied to the electrodes are indicated using voltage references V1, V2, ... to indicate that a voltage can be applied to that electrode. The voltages indicated by the different voltage references are typically different, but they may be equal. Driving the electrodes may use signals with a selected maximum amplitude. Using different voltages for one electrode, or for some electrodes, or for all electrodes, may result in visual differences in the panel, and in particular in different optical properties depending on specific, e.g., different transmittances. For example, the signal amplitude may be selected from multiple maximum amplitudes to achieve one of multiple transmittances. These signals may be alternating currents or alternating voltages.

[0167] The positive or negative sign indicates whether the voltage is positive or negative relative to zero voltage. Other examples of the same embodiment can be obtained by replacing all positive signs with negative signs and vice versa.

[0168] As an example, the various voltage references may be equal (other than sign), except for modifications applied to account for manufacturing variations, e.g., slightly different electrodes, uneven substrates, etc. As an example, the various voltage references may be different to create intermediate transmittances, e.g., various greys, or various colors, or intensities of color. As an example, intermediate voltages may be used to facilitate particle dispersion or collection. While the use of different voltage references is beneficial, one still obtains examples of beneficial light modulators by selecting all or some of the voltage references as equal (other than sign).

[0169] Typically, the electrodes are driven to DC neutral, for example by applying an AC signal to them, in which respect the voltage reference can be considered as the maximum amplitude of the AC signal, while the positive and negative signs indicate the phase of the signal.

[0170] The voltage sign (positive / negative indication) is therefore only for a particular period; the voltage sign for each electrode can be reversed for the next period. The figures are not entirely to scale, for example, the electrodes on the substrate are not necessarily equidistant. The arrows in the figures indicate the main electric field lines.

[0171] The figures show a light modulator comprising a first substrate and a second substrate between which an optical layer is present. A number of electrodes are applied on their inner side, each of which comprises a number of main lines. In the figures, the first and second substrates are also referred to as upper and lower for clarity. Although not indicated, the substrates may be in any position, and the upper and lower parts may be, for example, front and rear. The electrodes in these figures do not show extensions such as support lines, although extensions may be applied.

[0172] A controller may be connected to the illustrated light modulator to control the voltage created on the electrodes, for example as indicated by a voltage reference.

[0173] It should be noted that many of the improvements described herein, such as, for example, supporting wires, having more than two electrodes on a substrate, are beneficial, especially in combination; for example, supporting wires reduce diffraction, but this effect is increased when multiple electrodes reduce curtaining effects. However, these enhancements as described below and elsewhere herein are also indecently beneficial without a controller configured to obtain one of multiple levels of transparency or reflectivity in the light modulator, for example, by using an alternating current of one of multiple maximum amplitudes. The following embodiments can be configured for controllers that cannot be driven with alternating currents of different maximum amplitudes by choosing voltages that are indicated to be equal by the voltage reference.

[0174] 12-15 are schematic diagrams illustrating examples of embodiments of optical modulators having two electrodes applied on each substrate.

[0175] If one has at least four independent electrodes, for example wiring at least two electrodes on each substrate in a device, it is possible to modulate the electric field direction as shown in the figure. As mentioned above, it is possible to modulate the potential level for each electrode. By using a single potential reference, a simplified optical modulator is obtained.

[0176] FIG. 12 is a diagram showing an example of driving an optical modulator to increase the transmittance.

[0177] Figure 13 shows an example of driving a light modulator to reduce the transmittance. Note that oblique field lines are created to increase the particle dispersion speed. Furthermore, the particles will disperse more towards the middle of the light modulator, which reduces the curtain effect.

[0178] Figures 13 and 14 show two different ways to drive towards a darker state. Figure 14 shows an example where the light modulator is driven to increase both the vertical and horizontal electric fields. Which of the vertical and horizontal electric fields is stronger to drive the dye depends on the design, e.g., the dimensions of the cell spacing and the line spacing. The electric field becomes stronger when the distance between the electrodes is reduced and the particles move towards the field region where the electric field is strongest. If the electric field difference between the vertical and horizontal fields in this case is not strong enough, the light modulator will demonstrate an intermediate open state when the design is homogenous across the substrate.

[0179] If the design changes the light modulator and the distance between electrodes and between substrates in the same substrate is not constant across the light modulator, locally the highest electric field regions along which the charged particles will aggregate will change, resulting in optical differences. In some areas the light modulator may be more transparent, while in other areas it may be less transparent even with uniform electrical actuation. This effect is less achievable with other actuation methods, such as the one shown in FIG. 13. This effect can be used, for example, to embed a logo in the light modulator.

[0180] FIG. 15 is a schematic diagram showing an example of using an AC current of one of the maximum amplitudes. The first electrode on the upper substrate is driven with a reference voltage +V, while the second electrode on the upper substrate is driven with a reference voltage +V / 2. The counter electrodes on the lower substrate are driven with -V / 2 and -V, respectively. It should be noted that the voltage difference between the counter electrodes is + / -1.5V, while the voltage difference between the adjacent electrodes is + / -0.5V. As a result, the particles mostly react to the perpendicular electric field and settle to increase the transmittance, but to a lesser effect.

[0181] Figures 16 and 17 are schematic diagrams illustrating examples of embodiments where one substrate has two electrodes and the other has three electrodes, in which at least three electrodes are applied to at least one of the first and second substrates and at least two electrodes are applied to the other substrate.

[0182] When additional electrodes are available, additional combinations of voltages can be obtained, which gives more control over the grey scale, for example. For example, five electrodes instead of four allow addressing modes that are not possible with a four-electrode system.

[0183] Having at least three electrodes on the substrate can reduce the curtain effect; for example, the visual appearance of a curtain closing between the electrodes instead of a uniform stepwise increase or decrease in transmission. For example, one or more, or all, of the additional electrodes on one of the substrates can be used to close (reduce transmission) even if they are not used to open (increase transmission). This curtain effect is inherently visually distracting and also increases diffraction.

[0184] An advantage of having at least three electrodes on a substrate is that the electrodes can be spaced closer together without decreasing maximum transmittance or reflectance. For example, in an embodiment, the electrodes on a substrate having at least three electrodes may be spaced 35 microns apart, while the electrodes on an opposing substrate having, for example, two electrodes may be spaced 70 microns apart. These are exemplary figures; the actual figures may vary depending on the requirements of the application.

[0185] Closely spaced electrodes result in a stronger electric field and therefore faster closing, thus reducing the curtaining effect, whereas when open, there is only a small loss in maximum transmission or reflectance if the additional electrodes are configured not to attract particles.

[0186] In an embodiment, the additional electrodes may be formed from a different material than the other electrodes, such as a transparent material, for example, four electrodes may be formed from copper, while an additional fifth electrode is formed from ITO.

[0187] 16 and 17 show examples where the distance between the subsequent main lines of the electrodes on the first substrate is greater than the distance between the subsequent main lines of the electrodes on the second substrate. For example, the distance may be twice the distance shown. For example, the distance may be at least 2 times, 1.5 times, or 1.2 times, etc.

[0188] 16 and 17 show examples that facilitate reducing the transmittance.

[0189] 18-19 are schematic diagrams illustrating example embodiments of optical modulators having three electrodes on each substrate.

[0190] Having at least three electrodes on each side increases the advantage of having five electrodes. Since not all electrodes are required to open the device, the electrodes can be closer together on both sides without decreasing the transmittance. Furthermore, with three electrodes on each substrate, six electrodes can be arranged symmetrically.

[0191] 20-23 show schematic examples of optical modulator embodiments with four electrodes on one substrate and two electrodes on the other substrate. More electrodes allow for more modulation of the transmittance, controlled by design rather than by particle motion alone. As shown in FIG. 20, an optical modulator area can be set to spread the particles in the visible area, while other parts can be set to concentrate the particles in a vertical electric field. This allows for grayscale by design control. FIG. 21, FIG. 22, and FIG. 23 show other examples of the association of potentials across two electrodes and four electrodes to modulate grayscale.

[0192] Figures 24-29 show schematic examples of light modulator embodiments with four electrodes on each substrate, which allow even more control over grey scale.

[0193] Figure 30 is a schematic diagram of an example embodiment of a light modulator. The light modulator of Figure 30 has two electrodes on each side, but can be implemented with more than two electrodes.

[0194] The light modulator shown in Fig. 30 has further secondary electrodes running parallel to the primary electrodes. For example, the primary electrodes may be main or branch lines, etc. In Fig. 30, one primary electrode is indicated with reference number 3001 and one secondary electrode is indicated with reference number 3002. As shown, the secondary electrodes run alongside each of the primary electrodes, although this is not required.

[0195] In an embodiment, the secondary electrode is connected to the primary electrode through the semiconductor layer, and the secondary electrode is electrically connected to the primary electrode line by the semiconductor layer, which allows only a transmission current above a threshold voltage on the primary electrode. Thus, the voltage switch can be addressed by the potential.

[0196] Accordingly, the primary electrodes or parts thereof can be locally interconnected to the secondary electrodes. By interfacing with the semiconductor material layer, the transparent electrodes only see a potential when a minimum potential is applied on the electrode. This allows the creation of a voltage switch on the surface that is addressed by the potential. The secondary electrodes can be transparent. The second electrode can be the same or similar size as the primary electrode, or it can be much larger.

[0197] In an embodiment, the secondary electrode comprises a capacitor configured to hold a charge locally, which can be used for a gain in power. A semiconductor layer is not required to configure the extended electrode as a capacitor.

[0198] In an embodiment, the secondary electrode comprises a photovoltaic semiconductor material, and the secondary electrode provides power to the primary electrode wire.

[0199] 31-33 are schematic diagrams illustrating examples of embodiments of a substrate having two electrodes extending in two dimensions but offset in a third dimension. These diagrams show top views. The two electrodes are each disposed in a plane, but the planes are offset with respect to each other. For example, the electrodes may be etched.

[0200] An insulator may be placed between the first and second electrodes where they cross to avoid electrical connection. This structure therefore improves the reliability of the electrodes, as each electrode overlaps locally. It is therefore possible to bond the electrode wires in a mesh-like manner, not just in an interdigitated manner. If the electrodes do not overlap, they will remain in contact with the fluid.

[0201] This structure facilitates the creation of interdigitated electrodes and their reliability. It also allows for the creation of new electric field areas locally, for example with several transparent electrodes, to better spread the particles, e.g., dyes, over the surface. It also allows for the creation of new electric field areas locally, for example with several transparent electrodes, to better spread the particles, e.g., dyes, over the surface.

[0202] The interdigitated pattern of electrodes on each substrate allows the light modulator to be set to a particle-dispersed state, which typically results in a dark state. An electric field parallel to the substrates results in a high level of homogeneity. A distribution of the electric field along the perpendicular axis, i.e., from substrate to substrate, encourages particle concentration by the field lines and can be considered less homogeneous, whose physical inhomogeneity can be exploited to more easily create grayscales.

[0203] An offset between electrodes on the same substrate allows the angle between the interdigitated main lines to reduce the diffraction level. To further reduce the diffraction problem and / or to reduce parallax, supplementary lines can be created. In an embodiment, a passive matrix design is used.

[0204] Offsetting two electrode patterns at an angle may be applied in opposing substrates, but also between patterns on different substrates. For example, electrode patterns on different substrates may be offset at an angle. For example, in an embodiment, two or more interdigitated electrodes may be applied to two parallel substrates, where the main lines in the two substrates are not parallel, but are at an angle to each other.

[0205] FIG. 34 is a schematic diagram of an example embodiment of an optical modulator in which electrodes on a first substrate are arranged in at least a partially identical pattern to second electrodes on a second substrate, and the patterns of the first and second electrodes are shifted relative to each other.

[0206] In this example, misalignment based on a six-electrode system is shown. The misalignment reduces the parallax effect due to manufacturing alignment tolerances. One particular way of driving the system is shown in the figure.

[0207] The specific misalignment may be applied globally or only locally to the device. For example, the specific misalignment may be applied to the edges to prevent unwanted particle movement towards the edges, also known as dye migration effects. In embodiments, the alignment in specific locations may be modified to better accommodate future bending of the light modulator. By combining misaligned and aligned patterns between the substrates, optical effects such as diffraction and / or parallax may be improved.

[0208] For example, in an embodiment, two or more interdigitated electrodes may be applied to two parallel substrates, where the main lines in the two substrates are parallel but shifted with respect to each other.

[0209] 35 is a schematic diagram of an example embodiment of a light modulator having four electrodes on each substrate, in which different materials may be combined for the electrodes to reduce parallax.

[0210] For example, on each substrate, one of the two electrodes can be made of metal or transparent (e.g., ITO) or can have a different optical index. The electrodes on the opposing substrate can be made of other types of materials; for example, the transparent material can be reversed to a non-transparent material.

[0211] For example, in the 8-electrode system shown in Figure 35, the circled electrodes may be made of transparent (e.g. ITO) and the other electrodes may be made of metal (e.g. copper) and non-transparent. This reduces the effect of alignment tolerances on parallax even if the horizontal electrode shape design requires perfect alignment between the bottom and top substrates. Manufacturing variations also have less impact.

[0212] 36-37 are schematic diagrams illustrating example embodiments of light modulators having different geometries across the substrates. For example, the electrode geometries may vary across at least one of the first and second substrates, such as one or more of the electrode thickness, width, shape, area, and volume.

[0213] The use of different electrode geometries can be combined with any type of electrode structure.

[0214] In an embodiment, the electrodes do not have the same electrode height. Modifying the electrode height affects both the electric field distribution and the liquid flow. Similarly, the electrode shape parallel to the substrate can be from any form. The electrode shape in the vertical plane compared to the substrate can also be shaped differently, for example, rectangular with or without rounded corners, triangular, trapezoidal, etc.

[0215] Figure 36 shows examples of electrodes on substrates with different heights. Figure 36 also shows examples of counter electrodes on different substrates with different heights.

[0216] Figure 37 shows examples of electrodes on substrates with different shapes. Figure 36 also shows examples of counter electrodes on different substrates with different shapes.

[0217] The advantage of a greater height in the electrode is that it is less susceptible to corrosion.

[0218] The following numbered paragraphs include contemplated, non-limiting examples:

[0219] 1. An optical modulator comprising: - a first substrate and a second substrate, the inner sides of which are disposed opposite each other, and a plurality of electrodes (110, 120) are applied to the inner sides of each of the first and second substrates, each of the plurality of electrodes being arranged in a pattern across the substrate, each of the plurality of electrodes comprising: - a first substrate and a second substrate comprising a plurality of main lines extending in a first direction across the substrate, the main lines of the plurality of electrodes being alternatingly arranged with respect to one another on the substrate; an optical layer between the first substrate and the second substrate, comprising: an optical layer comprising a fluid containing particles, the particles being charged or chargeable; - a controller configured to apply potentials to the plurality of electrodes to obtain an electromagnetic field between the plurality of electrodes that results in electrophoretic movement of particles towards or away from one of the plurality of electrodes to generate a modulation of an optical property of the light modulator, the controller being configured to obtain one of a plurality of levels of transmittance or reflectivity in the light modulator by using an alternating current or an alternating voltage of one maximum amplitude of a plurality of maximum amplitudes. An optical modulator comprising:

[0220] 2. The optical modulator of claim 1, wherein the controller is configured to apply a potential difference between subsequent electrodes on the same substrate and simultaneously apply a potential difference between opposing electrodes on an opposing substrate.

[0221] 3. - at least three electrodes are applied to at least one of the first and second substrates, or - at least three electrodes are applied to both the first and second substrates; Item 3. An optical modulator according to item 1 or 2.

[0222] 4. An optical modulator described in any one of items 1 to 3, wherein the distance between subsequent main lines of the multiple electrodes on the first substrate is greater than the distance between subsequent main lines of the multiple electrodes on the second substrate.

[0223] 5. An optical modulator having a transmissive state and a non-transmissive state, or a reflective state and a non-reflective state, - switching to a non-transmissive or non-reflective state by creating an AC voltage on at least one of the first and second substrates, applying an AC voltage between at least a first electrode and a second electrode on the first substrate and / or a first electrode and a second electrode on the second substrate; - switching to a transmissive or reflective state by creating an AC voltage between the first substrate and the second substrate, applying an AC voltage 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. 5. The optical modulator according to any one of claims 1 to 4, configured as follows:

[0224] 6. The plurality of electrodes of at least one of the substrates comprises at least a first electrode and a second electrode, the first electrode and the second electrode each comprising: - a plurality of main lines extending in a first direction across the substrate, the plurality of main lines of the first and second electrodes being staggered with respect to one another on the substrate; - a plurality of branch lines extending from the main lines into an area between the main lines, the branch lines extending into an area between the first and second main lines of the first and second electrodes extending alternately from the first and second main lines and at least one of two subsequent branch lines extending into the same area extends at least half way across the area measured along a second direction perpendicular to the first direction.

[0225] 7. A light modulator as described in any one of claims 1 to 6, wherein two subsequent branch lines that extend into the same area between a first main line and a second main line overlap in a second direction when projected in a first direction.

[0226] 8. An optical modulator as described in any one of claims 1 to 7, wherein two subsequent branches extending into the same area between the first main line and the second main line have different lengths, the longer branch being at least 5% longer than the shorter branch.

[0227] 9. An optical modulator described in any one of claims 1 to 8, wherein the distance between the main lines and subsequent main lines on the substrate of the first electrode and the second electrode varies in the second direction and / or the first direction.

[0228] 10.The distance between the main lines is - Alternating between increasing towards the maximum distance and decreasing towards the minimum distance, and / or - Increased or decreased by random amounts within the maximum and minimum distances, and / or - a series of distances in a second direction between the main lines across the board are randomly varied, the sum of the distances being between a minimum total distance and a maximum total distance; Item 10. An optical modulator according to any one of items 1 to 9.

[0229] 11. A main line and a branch line extending from the main line are made up into a series of connected secondary lines from which the branch lines extend, and the series of secondary lines connect to form the main line; - the branches extending on the same side of a secondary main line have equal length, and / or - the branches extending on the same side of the secondary main are parallel, and / or - The number of branch lines extending from each side of the secondary line is equal, Item 11. An optical modulator according to any one of items 1 to 10.

[0230] 12. A branch line extending on the same side of a secondary main line and a branch line extending from a subsequent secondary main line of the same main line are - have different lengths, and / or - forming an angle different from the first direction, and / or - having a different number of branch lines extending from the sides of the secondary main line, Item 12. An optical modulator according to item 11.

[0231] 13. An optical modulator according to claim 11 or 12, wherein the angle between the branch line and the first direction of the secondary main line is randomly selected between 45 degrees and 90 degrees.

[0232] 14. An optical modulator according to any one of claims 11 to 13, wherein a secondary main line and a subsequent connected secondary main line of the same main line are shifted relative to each other in both the first direction and the second direction.

[0233] 15. An optical modulator described in any one of claims 1 to 14, wherein the pattern in which the first and second electrodes are arranged is subdivided into a set of blocks extending in first and second directions across the substrate, each block comprising a plurality of secondary lines that are a portion of the plurality of main lines of the first electrode and a plurality of secondary lines that are a portion of the plurality of main lines of the second electrode, and at least one of the blocks is repeated multiple times on the substrate.

[0234] 16. - In a portion of the block the secondary electrodes have multiple branches and in a portion of the block the electrodes do not have multiple branches; and / or - in part of the block the minor lines are straight and in part of the block the minor lines are wavy; Item 16. An optical modulator according to any one of items 1 to 15.

[0235] 17. An optical modulator described in any one of claims 1 to 16, wherein the pattern in which the electrodes are arranged is subdivided into multiple parts, and at least one of the electrode line spacing, electrode line thickness, electrode line width, electrode material, electrode line shape, and electrode line direction is different in the multiple parts, generating an optical effect.

[0236] 18. An optical modulator as described in any one of claims 1 to 17, wherein an electrode geometry selected from the group consisting of thickness, width, shape, area and volume varies across at least one of the first and second substrates.

[0237] 19. A primary electrode is connected at least in part to a further secondary electrode running parallel to the primary electrode; - a secondary electrode is connected to the primary electrode through a semiconducting layer, the secondary electrode being electrically connected to the primary electrode line by the semiconducting layer, thereby only allowing a transmission current above a threshold voltage on the primary electrode, and / or - the secondary electrode is transparent, and / or - the secondary electrode comprises a capacitor configured to locally hold a charge; and / or - the secondary electrode comprises a photovoltaic semiconductor material, the secondary electrode providing power to the primary electrode wire; Item 19. An optical modulator according to any one of items 1 to 18.

[0238] 20. An optical modulator described in any one of clauses 1 to 19, wherein the plurality of electrodes extends across the substrate in two dimensions and, in a third dimension, at least a first electrode of the plurality of electrodes is set apart from at least a second electrode of the plurality of electrodes, and optionally, an insulator is disposed between the first electrode and the second electrode.

[0239] 21. An optical modulator described in any one of claims 1 to 20, wherein the electrodes on the first substrate are arranged in at least partially the same pattern as the second electrodes on the second substrate, and the patterns of the first electrodes and the second electrodes are shifted relative to each other.

[0240] 22. A substrate for use in an optical modulator, wherein a plurality of electrodes are applied to a same side of the substrate, each of the plurality of electrodes being arranged in a pattern across the substrate, and at least a first electrode and a second electrode of the plurality of electrodes each comprise: - a plurality of main lines extending in a first direction across the substrate, the plurality of main lines of the first and second electrodes being staggered with respect to one another on the substrate; - a plurality of branch lines extending from a main line into an area between the main lines, the branch lines extending into an area between a first main line and a second main line of the first electrode and a second electrode extending alternately from the first and second main lines and at least one of two subsequent branch lines extending into the same area extends at least halfway across the area measured along a second direction perpendicular to the first direction.

[0241] 23. An optical modulator method comprising: 1. An optical modulator comprising: - a first substrate and a second substrate, the inner sides of which are disposed opposite each other, and a plurality of electrodes are applied to the inner sides of each of the first and second substrates, each of the plurality of electrodes being arranged in a pattern across the substrate, each of the plurality of electrodes comprising: - a first substrate and a second substrate comprising a plurality of main lines extending in a first direction across the substrate, the main lines of the plurality of electrodes being alternatingly arranged with respect to one another on the substrate; an optical layer between the first substrate and the second substrate, comprising: - an optical layer comprising a fluid containing particles, the particles being charged or chargeable; selecting an AC current or voltage from a plurality of maximum amplitudes corresponding to one of a plurality of levels of transmittance or reflectivity in the optical modulator; applying an alternating current to the electrodes to obtain an electromagnetic field between the electrodes that results in electrophoretic movement of the particles towards or away from the electrodes, causing modulation of the optical properties of the light modulator; An optical modulator method comprising:

[0242] 23. A transitory or non-transitory computer-readable medium containing data representing instructions that, when executed by a processor system, cause the processor system to perform the method of claim 22.

[0243] It should be noted that the above-described embodiments are illustrative rather than limiting of the subject matter of the present disclosure, and that those skilled in the art may design many alternative embodiments.

[0244] In the claims, reference signs enclosed in parentheses shall not be construed as limiting the scope of the claims. Use of the verbs "comprise" and "include" and their conjugations does not exclude the presence of elements or steps other than those stated in the claims. The article "a" or "an" before an element does not exclude the presence of a plurality of such elements. A phrase such as "at least one of," when following a list of elements, denotes the selection of all or any subset of the elements from that list. For example, the phrase "at least one of A, B, and C" should be understood as including A only, B only, C only, both A and B, both A and C, both B and C, or all of A, B, and C. The subject matter of the present disclosure may be implemented by hardware comprising several distinct elements, and by a suitably programmed computer. In a device claim reciting several parts, several of those parts may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0245] In the claims, references in parentheses refer to the reference signs in the drawings of the illustrated embodiments or to the formulas of the embodiments, thus making the claims easier to understand. These references should not be interpreted as limiting the scope of the claims.

Claims

1. An optical modulator a first substrate and a second substrate, the inner sides of which are arranged facing each other, a first electrode and a second electrode being applied to the inner sides of each of the first and second substrates, each of the first electrode and the second electrode being arranged in a pattern across the substrate, each of the first electrode and the second electrode being: - comprising a plurality of main lines extending in a first direction across a substrate, the main lines of the first electrode and the second electrode being arranged alternately with respect to one another on the substrate, the first electrode and the second electrode each comprising: a first substrate and a second substrate comprising a plurality of branch lines extending from a main line into an area between the main lines, the branch lines extending into an area between a first main line of a first electrode and a second main line of a second electrode extending alternately from the first and second main lines, at least one of two adjacent branch lines extending over an area of ​​at least half the distance between the main lines measured along a second direction perpendicular to the first direction; an optical layer between the first and second substrate, an optical layer comprising a fluid containing particles, the particles being charged or chargeable; a controller configured to apply potentials to the first and second electrodes to obtain an electromagnetic field between the first and second electrodes that results in electrophoretic movement of particles towards or away from one of the first and second electrodes to generate a modulation of an optical property of the light modulator, the controller being configured to obtain one of a plurality of levels of transmissivity or reflectivity in the light modulator by using an alternating current or voltage of one maximum amplitude of a plurality of maximum amplitudes. An optical modulator comprising:

2. 10. The light modulator of claim 1, wherein the controller is configured to simultaneously apply a potential difference between adjacent electrodes on the same substrate and to simultaneously apply a potential difference between opposing electrodes on opposing substrates.

3. at least three electrodes are applied to at least one of the first and second substrates, or at least three electrodes are applied to both the first and second substrates; 2. The optical modulator according to claim 1.

4. 2. The optical modulator of claim 1, wherein a distance between adjacent main lines of the first electrode and the second electrode in the first substrate is greater than a distance between adjacent main lines of the first electrode and the second electrode in the second substrate.

5. 1. A light modulator having a transmissive state and a non-transmissive state, or a reflective state and a non-reflective state, - switching to a non-transmissive or non-reflective state by applying an alternating current between at least the first and second electrodes on the first substrate and / or between the first and second electrodes on the second substrate, switching to a transmissive or reflective state by 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; The optical modulator according to claim 1 , configured as follows:

6. An optical modulator as described in claim 1, wherein two adjacent branch lines extending into the same area between a first main line of a first electrode and a second main line of a second electrode overlap in a second direction when projected in a first direction.

7. An optical modulator as described in claim 1, wherein two adjacent branch lines extending into the same area between a first main line of a first electrode and a second main line of a second electrode have different lengths, the longer branch line being at least 5% longer than the shorter branch line.

8. 2. The optical modulator of claim 1, wherein the distance between main lines and adjacent main lines on the substrate of the first and second electrodes varies in the second direction and / or in the first direction.

9. The distance between the main lines is - Alternating between an increase towards a maximum distance and a decrease towards a minimum distance, and / or - Increased or decreased by a random amount within the maximum and minimum distances, and / or a series of distances in a second direction between the main lines across the substrate is randomly varied, the sum of the distances in the series of distances being between a minimum total distance and a maximum total distance; 9. The optical modulator according to claim 8.

10. a main line and branch lines extending from the main line are made up into a series of connected minor lines from which the branch lines extend, the series of minor lines joining to form the main line; - the branches extending on the same side of a secondary main line have equal length, and / or - the branches extending on the same side of a secondary main line are parallel, and / or - the number of branches extending from each side of the secondary main line is equal; 2. The optical modulator according to claim 1.

11. branch lines extending on the same side of a minor line and branch lines extending from adjacent minor lines of the same major line; - have different lengths, and / or - forming an angle different from the first direction, and / or - have a different number of branch lines extending from either side of the secondary main line, The optical modulator according to claim 10.

12. 11. The optical modulator of claim 10, wherein an angle between the branch line and the first direction of the minor line is randomly selected between 45 degrees and 90 degrees.

13. 11. The optical modulator of claim 10, wherein submain lines and adjacent connected submain lines of the same main line are shifted relative to each other in both the first direction and the second direction.

14. 2. The optical modulator of claim 1, wherein the pattern in which the first and second electrodes are arranged is subdivided into a set of blocks extending in first and second directions across the substrate, each block comprising a plurality of minor lines that are a portion of a plurality of main lines of the first electrode and a plurality of minor lines that are a portion of a plurality of main lines of the second electrode, and at least one of the blocks is repeated multiple times on the substrate.

15. - in a portion of the block the secondary electrodes have multiple branches and in a portion of the block the electrodes do not have multiple branches; and / or - in a part of the block the minor lines are straight and in a part of the block the minor lines are wavy; 15. The optical modulator of claim 14.

16. The optical modulator of claim 1, wherein a pattern in which the electrodes are arranged is subdivided into a plurality of portions, and at least one of the electrode line spacing, electrode line thickness, electrode line width, electrode material, electrode line shape, and electrode line direction is different in the plurality of portions to generate an optical effect.

17. 10. The optical modulator of claim 1, wherein an electrode geometry selected from the group consisting of thickness, width, shape, area and volume differs between the first electrode and the second electrode of at least one of the first and second substrates.

18. The main or branch wires are connected at least in part to a further secondary electrode running parallel to the primary electrode; the secondary electrode is connected to the primary electrode through the semiconducting layer, the secondary electrode being electrically connected to the primary electrode line by the semiconducting layer, thereby only allowing a transmission current above a threshold voltage on the primary electrode, and / or the secondary electrode is transparent, and / or the secondary electrode comprises a capacitor arranged to locally hold a charge, and / or the secondary electrode comprises a photovoltaic semiconductor material and supplies power to the primary electrode wire; 2. The optical modulator according to claim 1.

19. An optical modulator as described in claim 1, wherein the first electrode and the second electrode extend in two dimensions across the substrate, and in a third dimension, at least a first of the first electrode and the second electrode is set apart from at least a second of the first electrode and the second electrode, and optionally, an insulator is disposed between the first electrode and the second electrode.

20. 2. The optical modulator of claim 1, wherein the electrodes on the first substrate are arranged in at least partially the same pattern as the second electrodes on the second substrate, and the patterns of the first and second electrodes are shifted relative to each other.

21. 1. An optical modulator method comprising: providing an optical modulator, the optical modulator comprising: a first substrate and a second substrate, the inner sides of which are arranged facing each other, a first electrode and a second electrode being applied to the inner sides of each of the first and second substrates, the first electrode and the second electrode of at least one of the substrates comprising at least a first electrode and a second electrode, each of the first electrode and the second electrode being arranged in a pattern across the substrate, each of the first electrode and the second electrode being: - comprising a plurality of main lines extending in a first direction across a substrate, the main lines of the first electrode and the second electrode being arranged alternately with respect to one another on the substrate, the first electrode and the second electrode each comprising: a first substrate and a second substrate comprising a plurality of branch lines extending from a main line into an area between the main lines, the branch lines extending into an area between a first main line of a first electrode and a second main line of a second electrode extending alternately from the first and second main lines, at least one of two adjacent branch lines extending over an area of ​​at least half the distance between the main lines measured along a second direction perpendicular to the first direction; an optical layer between the first and second substrate, - providing a fluid containing particles, the particles being charged or chargeable; providing an optical layer; selecting an AC current or voltage of one of a plurality of maximum amplitudes corresponding to one of a plurality of levels of transmittance or reflectivity in the light modulator; applying an alternating current to the electrodes to obtain an electromagnetic field between the electrodes that results in electrophoretic movement of the particles towards or away from the electrodes, causing modulation of the optical properties of the light modulator; An optical modulator method comprising:

22. 22. A transitory or non-transitory computer readable medium containing data representing instructions that, when executed by a processor system, cause the processor system to perform the method of claim 21.

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