Light modulator, substrate comprising electrodes, and smart glazing

Abstract

To provide an optical modulator having substrates to which less diffraction may be applied, thereby contributing to a more uniform opaque state and a more uniform transition rate.SOLUTION: The present invention relates to a light modulator comprising transparent or reflective substrates, a plurality of electrodes being applied to the substrates in a pattern across the substrate. A controller may apply an electric potential to the electrodes to obtain an electromagnetic field between the electrodes providing electrophoretic movement of particles toward or away from the electrodes.SELECTED DRAWING: Figure 18

Description

Technical Field

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

Background Art

[0002] U.S. Patent Application No. 11 / 041579, "Optically active glazing", Publication No. US20050185104A1, discloses a known optically active glazing, which is incorporated herein by reference.

[0003] This known system comprises two parallel plates made of a transmissive dielectric material such as glass or plastic material. The internal volume defined between the plates is subdivided into a plurality of independent small volumes or individual cells filled with a dielectric liquid. This liquid contains a suspension of particles of the dielectric material. The opposing surfaces of the two plates carry electrodes facing each other. These electrodes are connected to a power source associated with control means.

[0004] The electrodes of each plate have a comb shape with pairs arranged alternately with each other. The two alternately arranged combs of electrodes can take voltages of the same polarity or opposite polarities. When an appropriate voltage is applied to the electrodes, the particles can be collected at various locations between the electrodes in order to give the system either a transmissive or non-transmissive appearance.

[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 a diffraction effect. The diffraction effect is not desirable for the glazing. Depending on the situation, the presence of the diffraction effect can also be detrimental to safety. For example, when an optically active glazing is applied to a vehicle such as an automobile, the presence of diffraction can be distracting or cause the operator of the vehicle to lose attention.

[0006] Furthermore, the driving 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 can also affect safety. For example, if the glazing is configured to be intermediate between opaque and transparent, a lack of uniformity may result in it being confusing or distracting.

[0008] Yet another drawback is that when the glazing transitions from an opaque configuration to a transparent 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

Patent Document 2

Non-Patent Documents

[0010]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0011] It would be beneficial to have an improved substrate with two electrodes dispersed therein to address the above and other problems. The inventor has discovered that the electrode design in known systems results in diffraction and also results in an electric field that is not completely uniform. Addressing the first problem results in a substrate to which less diffraction can be applied. Addressing the second problem contributes to a more uniform opaque state across the substrate and a more uniform transition rate.

Means for Solving the Problems

[0012] Smart glazing is an important application of a transmissive or reflective substrate to which electrodes are applied. For example, a transmissive or reflective substrate for applications such as these smart glazings can have two electrodes each having a plurality of main lines. These lines are arranged alternately on the substrate, and thus, an electric field can be established between subsequent or adjacent lines by providing a potential difference to the electrodes.

[0013] From these main lines, a plurality of branch lines can extend. By extending the branch lines by at least half the distance between two main lines, better homogeneity and / or a lower diffraction effect can be obtained. Further, two subsequent branch lines that extend into the same area between a first main line and a second main line can overlap in a second direction when projected in a first direction. These branch lines increase the number of angles seen on the substrate, and accordingly reduce the diffraction effect. For example, an angle different from vertical may be selected and / or varied further to reduce diffraction. Diffraction can also be reduced by varying the distance between the main lines and subsequent main lines on the substrate.

[0014] The substrate according to the embodiment can be used in an optical modulator, also known as a light modulator. For example, two such substrates may be arranged opposite to each other, and thus, by applying a voltage to the electrodes, charged particles floating in the fluid between the substrates can be made movable. Typically, the electrode designs for the lower substrate and the upper substrate are the same, but this is not essential. Similarly, the two designs are typically aligned with each other, but this is also not essential. The particles may absorb light or reflect light. The reflection may be specular, diffusive, or intermediate. The particles may emit light having, for example, phosphorescence or fluorescence.

[0015] The optical modulator provides a panel whose transmittance or reflectance can be modified. In an embodiment, things such as color or color intensity may be changed. The optical modulator can be used as a cover, for example, as a cover of a container such as a closet, a cabinet, etc. A particularly beneficial use is in smart glazing. Smart glazing is also called a smart window.

[0016] In an embodiment, the controller is configured to apply a potential to the electrodes on the substrate of the modulator in order to obtain an electromagnetic field between the electrodes. This electromagnetic field causes electrophoretic movement of particles towards or away from the electrodes. When the particles change their position, the optical properties of the panel, such as its transmittance or reflectance, change. If the particles are colored, the color of the panel can also change. By changing the pair of electrodes between which an electric field is established, the particles can be moved in a desired direction. The inventor has discovered that the control of the modulator does not have to be limited to only changing the electrodes to which an 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, by driving with a lower maximum amplitude, the rate of change in the modulator is changed. This is beneficial because the maximum amplitude can be reduced to avoid overshoot when driving towards a desired target transmittance or reflectance, for example. The maximum amplitude can also, or instead, be increased when starting to drive towards the target transmittance or reflectance. For example, by using an alternating current of one of a plurality of maximum amplitudes, the controller can be configured to obtain one of a plurality of levels of transmissivity or reflectivity in the modulator. This relationship can be represented by an algorithm or the like. The relationship between the level of transmissivity or reflectivity and the maximum amplitude can be managed, for example, by a look-up table showing a series of maximum amplitudes for driving towards the transmittance or reflectance. It should be noted that an alternating voltage is also possible.

[0017] In addition to changing the electrodes to which a signal is applied, changing the maximum amplitude of the drive signal can also be used to improve balanced driving. For example, the power applied, such as the maximum amplitude, on some electrodes may be different from that applied to other electrodes. For example, the controller may be configured to apply a potential difference between subsequent electrodes on the same substrate and simultaneously apply a potential difference between opposing electrodes on the opposing substrate.

[0018] In an embodiment, at least two electrodes are present on each substrate, but more than two electrodes may be present. 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 modulator may be driven so that the so-called curtain effect is reduced. This curtain effect occurs while the window is closed and makes it appear as if a curtain is being drawn between the electrodes. This curtain effect is a drawback, essentially visually distracting and also increasing diffraction. On the side with three electrodes, the electrodes can be brought closer together than on the two-electrode side, for example less than 50 microns, more preferably less than 40 microns, for example 35 microns together. This means that the electric field is stronger. Accordingly, it closes faster and the curtain effect is reduced. Moving the 2+2 panel to bring the electrodes closer together can lead to a reduction in the maximum transmittance or reflectance. However, this can be avoided if additional electrodes are available. When open, some of the additional electrodes may be unused, so the loss of maximum transmittance or reflectance is small. Additional electrodes on the substrate, for example more than two electrodes, can be configured to not attract particles when the panel is open but to attract particles when the panel is closed. For example, a panel in which each substrate has 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 stacked together using three substrates, with the middle substrate having two electrodes on each side.

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

[0021] Smart glazing is an electronic device and can be driven by a power source under the control of, for example, a controller. For example, the controller may command the power source to apply a specific waveform to a specific electrode in order to achieve various transmission or reflection effects, or the lack thereof.

[0022] Embodiments of this method may be implemented on a computer as a computer-implemented method, or in dedicated hardware, or a combination of both. The executable code of embodiments of this method 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 embodiments of this method when the said program product is executed on a computer.

[0023] In an embodiment, the computer program includes computer program code configured to perform all or part of the steps of embodiments of this method 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. The elements in the drawings are illustrated to be simplified and clarified, and are not necessarily drawn to scale. In the drawings, elements corresponding to those already described may have the same reference numerals. The drawings include the following.

Brief Description of the Drawings

[0025]

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[0026] List of Reference Numerals The following list of reference symbols and abbreviations is provided to facilitate the 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 substrate 13, 13a, 13b Electrodes 14, 14a, 14b Electrodes 15 Fluid 16 Controller 30 Particles 20 Vehicle 21 Optical modulator 40 Optical modulator 41 First substrate 42 Second substrate 43 Third substrate 46 Controller 100 Substrate 101 First direction 102 Second direction 110 First electrode 120 Second electrode 111 - 113 Main lines 121 - 123 Main lines 131 - 134 Branch lines 141 - 144 Branch lines 150 Area 151 Half of the distance between two subsequent main lines 152 Distance between two subsequent branch lines 153 Distance between two subsequent main lines 161 Projection 162 Virtual line 171 - 174 Substrates 200 Substrate 201 - 206 Main lines 251 - 253 Distance between subsequent main lines 221 First part 222 Connection part 223 Second part 231 Line interval 232 Distance 300 Substrate 301 Main line 310, 320 Sub-main lines 311 Connection 321, 322 Sub-main lines 400 Substrate 410, 420 Main lines 411, 412 Branch lines 421, 422 Branch lines 450 Substrate 451 - 454 Blocks

[0027] The subject matter of the present disclosure can have many different forms of embodiments. One or more specific embodiments are shown in the drawings and described in detail herein. The present disclosure is considered as an example of the principles of the subject matter of the present disclosure and is understood not to be limited to the specific embodiments illustrated and described.

[0028] In the following, for the sake of understanding, the elements of the embodiments are described with respect to their operations. However, it is clear that each element is configured to perform the functions described as being performed by them. Furthermore, the subject matter disclosed herein is not limited to just the embodiments, but also includes other combinations of the features described herein or in the respective dependent claims that are different from each other.

[0029] FIG. 1a schematically shows an example of an embodiment of substrate 100. There are at least two electrodes arranged in a pattern across the surface of substrate 100. FIG. 1a shows two electrodes on the same surface: a first electrode 110 and a second electrode 120. For example, to facilitate finer control, there may be more than two electrodes on the same side of the substrate. For example, a plurality of electrodes may be used to facilitate a segmented substrate, for example, for a segmented optical modulator. For example, in a segmented optical modulator, some zones may have different optical properties, such as different transmittances or reflectances. In the following, an embodiment having two electrodes is shown, but additional electrodes may be added to these two electrodes, for example, by replicating similar structures adjacent to each other.

[0030] The first electrode 110 and the second electrode 120 are applied to the same side portion of the substrate. These two electrodes are arranged in a pattern across the 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. Applying the electrodes to the substrate can be done by lithography, for example, using a mask representing the electrode pattern. The electrodes can 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 plurality of main lines of the 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. When viewed in a second direction 102, the main lines are alternately encountered from different ones, for example, from the first and second pluralities in the first and second electrodes, respectively. The first and second directions are angled with respect to each other, and typically, the angle is approximately perpendicular. The first and second directions may each be parallel to the side portion of the substrate, but this is not essential.

[0032] Desirable applications for substrates such as substrate 100 are in smart glazing, such as for optical modulators, and can be applied in homes, offices, greenhouses, automobiles, etc. The level of transmissivity or reflectivity of the smart glazing can be electrically configured. For example, in smart glazing, two substrates such as substrate 100 may be laminated, whereby the sides to which two electrodes are applied face each other. A fluid having particles is enclosed between the two substrates. Embodiments of smart glazing are further described below. In an embodiment, electrodes, for example, two or more electrodes are 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 following embodiments show examples of modulating the transmissivity level or reflectivity level. The optical modulator can be configured for other optical effects. For example, if necessary, the embodiment can be modified to different light transmissivity levels instead of different transmissivity levels. If necessary, the types of particles that can be used in the embodiment can be changed according to, for example, particles having different absorption or reflection wavelengths and the degree of specular or diffuse reflection of their reflection. For example, in an embodiment, the optical modulator can modulate different reflection levels. The particles may also emit light. Stacking multiple optical layers further increases the possibility.

[0034] Having two sets of alternating main lines is sufficient to provide electrically configurable glazing; for the two alternating sets, the electric field of any part of the substrate can be controlled such that two opposing electrodes border the part from two opposing sides. However, very straight main lines without further modification result in generating a high level of diffraction, which is undesirable.

[0035] By conforming the shape of the electrodes, the diffraction effect can be varied. For example, in the case of a reflective display such as may be applied to an e - book reader, the effect is not significant, so reducing the diffraction effect is particularly important in the case of a transmissive substrate. The inventor has found that in order to spatially spread out the diffraction, by orienting the wire shape of the electrodes at a plurality of different angles, the light diffraction may be reduced, and thus the brightness of most of the concentrated diffraction spots is reduced.

[0036] Figure 1a schematically shows the main lines without various decorations according to an embodiment. In Figure 1a, for clarity, the so - called branch lines are not shown, but such branch lines may exist.

[0037] Figure 1b is a diagram schematically showing an example of an embodiment of the substrate 100. Two of the main lines of the substrate 100 are shown in more detail in Figure 1b. The main line 121 and the main line 112 are shown. These main lines run across the main part of the substrate and may, for example, run across substantially the whole of the substrate.

[0038] As shown in FIG. 1b, a plurality of branch lines are attached to and extend from a main line. FIG. 1b shows branch lines 131 - 134 included in electrode 121 and branch lines 141 - 144 included in electrode 112. These branch lines are attached to the main line and extend into the area between the main lines. FIG. 1b shows one such area: area 150 between electrode 121 and electrode 112. Branch lines 131 and 132 of electrode 121, and branch lines 141 and 142 of electrode 112 extend into area 150 between electrode 121 and electrode 112. Similar to the main lines, the branch lines are also alternating. In particular, the branch lines extending from two different electrodes into the same area are alternating when viewed, for example, in a first direction. In this example, branch lines 142, 132, 141, and 131 alternately belong to electrodes 112 and 121. Thus, in an embodiment, the main lines are alternating when viewed in a second direction and the branch lines are alternating when viewed in the first direction. The branch lines are included in either the first electrode or the second electrode. Typically, the first and second electrodes including those 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 that includes those main lines and branch lines therebetween.

[0039] For example, when a virtual line is drawn in an overlapping area parallel to two subsequent main lines, this virtual line can alternately intersect with branch lines from the first main line and branch lines from the second main line, etc.

[0040] Extending branch lines from the main line has several advantages. These branch lines affect the diffraction of the substrate even in the case of a straight main line. On the other hand, the branch lines increase the risk of disturbing the homogeneity of the electric field. In particular, hot spots can be created where the tips of the branch lines are close, and weak spots can be created in other places. In an embodiment, at least one of two subsequent branch lines extending into the same area extends at least half across that area. As a result, the non - transmissive state may become more homogeneous, and the transition between states may be faster and / or more homogeneous.

[0041] When those branch lines are perpendicular to the main line, the point where a branch line occurs on one main line is directly opposite the occurrence point on the adjacent main line (when viewed in the second direction), and thus the branch lines cannot overlap. In this case, the branch line emerging from one main line is on the same line as the branch line from the opposing main line, such that, for example, extending the branch line would cause it to overlap with the branch line from the opposing main line. In such a case, there is a risk that hot spots are created where the tips of the branch lines are close, and weak spots are created elsewhere. This can be avoided, for example, by an appropriate angle such that an appropriate overlap exists. For example, this angle may depend on, for example, the line width and the line spacing.

[0042] For example, avoiding hot spots due to branch lines on the same line, such as perpendicular branch lines, can, in an embodiment, be avoided by interlocking the branch lines. For example, the points on the main line where the branch lines occur may be offset from each other or may be staggered. This angle may be selected such that the branch lines do not cross the next branch line. Staggering may be used to avoid the branch lines being on the same line. In an embodiment, the branch lines are perpendicular to their main lines and are staggered with respect to the branch lines of the subsequent main line. In an embodiment, the branch lines may not be perpendicular and may or may not be staggered. In an embodiment, for example, the angle of the branch lines may be selected from, for example, the range of about 5 degrees to about 85 degrees. When the line spacing is very large, the angle may approach perpendicularity.

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

[0044] In an embodiment, these branch lines form angles with those electrodes that are significantly different from perpendicular, for example, at least 5 degrees different (out of 180 degrees), for example, at least 5% of a right angle, etc. By having different values, the diffraction effect is reduced.

[0045] In an embodiment, two subsequent branch lines extending into the same area between the first main line and the second main line overlap in the second direction when projected in the first direction. For example, FIG. 1b shows two subsequent branch lines: branch lines 141 and 131. The area where these two branch lines overlap is shown as a dashed ellipse in FIG. 1b. When these two subsequent branch lines are projected in the first direction on virtual line 162 extending in the second direction, branch lines 131 and 141 overlap at projection 161. FIG. 5a shows examples of both a case with less overlap and a case with more overlap.

[0046] For example, simulations for embodiments having branch lines entering the area only with the following amounts: 60 - 50; 63 - 46; 64 - 45; 60 - 46, 65 - 61; 83 - 78; 95 - 95 were successfully carried out. Figure 1b shows branch lines having an entry of 80 - 40 and an overlap of 20 in terms of the percentage of line intervals. These numbers refer to the percentage of the line interval into which the branch line enters. The length of the branch line is measured here, for example, only along the second direction 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 the line interval.

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

[0048] In an embodiment, when measuring the distance between two subsequent branch lines from the same main line extending within the same area between the first main line and the second main line in the first direction, it may be significantly smaller than the line interval. For example, the said branch line distance may be no more than 5% of the line interval. However, other embodiments have, for example, a large distance of 30% or more of the line interval. For example, branch lines 131 and 132 extend into the same area between main lines 121 and 112.

[0049] Generally speaking, when branch lines are applied across the design, for example, the beneficial effects of applying the branch lines are enhanced. For example, it is not necessary for the branch lines to be applied to all parts of the substrate, but by doing so, the favorable effects of the branch lines can be recognized throughout. However, there may be various reasons for not using branch lines in some parts, for example, parts where an optical difference is desired, for example, to visually distinguish that part, or parts that use different methods to avoid diffraction, such as waves.

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

[0051] Two subsequent branch lines of different main lines may have the same length or different lengths. This offsets the area where the two branch lines overlap.

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

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

[0054] In an embodiment, the electrode includes a plurality of linear 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 and is, for example, 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 can be repeated.

[0055] For example, the distance between points where branch lines occur on the main line may be referred to as the branch line interval. This branch line interval can be constant in the case of branch lines extending within the same area. The branch line interval may also vary along the main line. The branch lines may be alternating or staggered, for example, they may be offset by half of the branch line interval between them. The advantage of the branch lines is that they can make the distance between the electrodes uniform, and thus an electric field can be established between the electrodes. At the same time, the diffraction effect can be reduced, for example, by disturbing the repeatability of the design.

[0056] In an embodiment, the electrode line has a width selected from the range of about 1 to 50 micrometers. This line interval can be selected from the range of about 50 to 100,000 micrometers. For example, the line interval may be 800 micrometers, for example, within the range of 50 - 1000 micrometers, but even larger line intervals are possible. By having branch lines, a uniform electric field can be maintained while having a large line interval. By increasing the line interval, the diffraction effect associated with the main line is reduced. In an embodiment, the line interval is at least 500 micrometers.

[0057] In an embodiment, the length of the branch lines can vary. For example, the lengths of the branch lines may alternate along the main line, or may follow, for example, the lengths of a series of repeated branch lines. This has the advantage of staggering the points of maximum electric field. This is particularly beneficial in the case of large line intervals, for example, 500 micrometers or the like. For example, in an embodiment, the length of subsequent branch lines may differ by about 60%.

[0058] In an embodiment, a plurality of main lines of the first and second electrodes are alternately arranged on a substrate with respect to each other. One way to achieve this is by forming the first and second electrodes in a comb shape, where the teeth of the comb are the main lines. By intermeshing the teeth of two combs, an intermeshing pattern is obtained. It is not necessary to use two comb shapes. For example, FIG. 1d is a diagram schematically showing an example of an embodiment of a first electrode and a second electrode arranged in a pattern across a substrate. For the sake of brevity, FIGS. 1a and 1d show only the main lines and not the branch lines. This 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] Designs with branch lines contribute to reducing diffraction by increasing the number of angles on the substrate. Furthermore, many parameters can be changed to increase this effect. For example, the length of the branch lines, the angle of the branch lines, the distance between branch lines along the main line, the line pitch, etc. can be changed. Preferably, the branch lines within the same area are at least locally parallel, and thus the branch line angle on the right side of the main line is the same as the branch line angle on the left side of the next main line. When the line pitch is changed, the branch line distance may also change proportionally depending on, for example, the line pitch; for example, in order to implement a minimum intensity in the electric field, the maximum electrode distance between two successive branch lines can be maintained.

[0060] FIG. 2a is a diagram schematically showing an example of an embodiment of a substrate 200. Four of the main lines: main lines 201 - 204 are shown in FIG. 2a. For example, main lines 201 and 203 may be included in a first electrode, such as electrode 110, and main lines 202 and 204 may be included in a second electrode, such as electrode 120. A line pitch 251, for example, the distance between main lines 201 and 202, is shown. Also shown are the line pitch 252 between main lines 202 and 203 and the line pitch 254 between main lines 203 and 204. In this example, the line pitch varies in a second direction. For example, line pitch 251 is different from line pitch 252, and line pitch 252 is different from line pitch 253. Changing the line pitch contributes to reducing the diffraction effect.

[0061] Figure 2b is a diagram schematically showing an example of an embodiment of a substrate. Main lines 201 - 206 are shown. These main lines have different portions where the line intervals can vary differently. For example, a portion or region of a main line can extend in a second direction across the substrate. In Figure 2b, two portions: portion 221 and portion 223 are shown. As illustrated in Figure 2b, in portion 221, the line intervals are proportional to 11, 9, 7, 9, 11, while in portion 223, the line intervals are proportional to 7, 11, 9, 9, 11. The line interval between two successive main lines thus varies in the first direction as well as in the second direction in this example. Between the first portion 221 and the second portion 223, there is a connection portion 222 where the main lines of the two portions are connected. The line intervals in portion 221 are selected according to an alternating increase and decrease pattern of the line intervals. The line intervals in portion 223 are randomly selected.

[0062] For example, in an embodiment, the line intervals alternate between an increase to a maximum distance and a decrease to a minimum distance. For example, it may increase by a predetermined amount or a randomized amount until it reaches the maximum distance, and then the line interval may be decreased in the same way until it reaches, for example, the minimum line interval. Various strategies are given below to ensure that the line intervals vary overall.

[0063] For example, in an embodiment, until it reaches the maximum value, for example, until it has an additional 20% compared to the initial value, the line interval is increased by 3%. For example, i if x is the line interval and x0 is the initial line interval, i x can have x i+1 = i * 1.03 until x > 1.2 * x0. After that point, the line interval may decrease in the same pattern or by the same percentage or the value may be reset and the pattern starts 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, until reaching the point of x i <up to the point of x0-10, rule x i+1 =1.07*x i and rule x i+1 =0.93*x i can 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) can be set. Also in this case, the line spacing can be reset when exceeding the maximum or minimum value. Values of α greater than 1 or less than 1 can alternate; for example, x i+1 =α i (x i -x0) can be used, with even indices i using α i >1 and odd indices using α i <1.

[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, odd line spacings may be derived from a probability distribution different from that of 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 intervals are randomly selected or modified, additional criteria can still be met. Above, it was stated to implement a maximum line interval and a minimum line interval. Another beneficial criterion that can be implemented is that the sum of the line intervals lies between a minimum total distance and a maximum total distance. This has the advantage that the connection portion 222 remains controlled. This can be obtained by deriving from a combined distribution conditioned on the desired criteria. This can also be obtained, for example, by first randomly selecting and then modifying that random selection until the constraints are met.

[0069] For example, in an embodiment, min x ≦ x i ≦ max x and min s ≦ Σx i ≦ max s where, if min x , max x , min s , max s are limits regarding the line intervals and the sum of the line intervals, the line intervals x i may be selected. These line intervals may vary randomly, for example, in a predetermined pattern as proposed above, or derived from one or more distributions.

[0070] The line spacing may be varied in a second direction along with the first direction. In this case, the variation can be controlled in order to control the shape of the connection portion. For example, FIG. 2c is a diagram schematically showing an example of an embodiment of a substrate. Two main lines 201 and 202 are shown. At the upper part of FIG. 2c, there is a line spacing 231. This line spacing changes at the lower part of FIG. 2c. The main line 201 is shown by a dashed line as to how it would continue if no shift occurred. The distance 232 is the distance between the main line 201 shown by the dashed line after the shift at the lower part of the figure and the main line 202. By maintaining a percentage increase or decrease of the distance 232 compared to the line spacing 231 less than the threshold value, the connection portion is controlled, for example, to prevent it from becoming too abrupt. For example, in an embodiment, the distance 232 is less than 1.35 times the line spacing 231. This variation of the line spacing can be controlled similarly. Instead of (or in addition to) controlling the size of the line spacing, the angle formed by the connection portion in the main line, for example, the angle formed by the connection portion in lines 201 and 202, etc., is controllable, and for example, in order to avoid the line becoming too abrupt, the angle should be controlled to be less than the threshold value. Another way to control this is to verify that subsequent connection portions do not approach each other too closely.

[0071] According to simulation experiments, it is confirmed that varying the line spacing is beneficial in reducing diffraction compared to a constant line spacing. It has also become clear that the randomness of the line spacing acts well in reducing the diffraction effect. Although the gradient pattern within the line spacing can reduce diffraction, a more randomized change in the line spacing does not act as well. For example, when the line spacing alternates between a randomly low value and a randomly high value, the diffraction is most reduced. The diffraction effect can be further suppressed by the branch lines.

[0072] Selecting an effective electrode pattern can be performed by a computer. For example, it is possible to automatically generate a number of electrode patterns and calculate diffraction parameters indicating the severity of the diffraction effect for those patterns. In some cases, other parameters can also be calculated, such as a homogeneity parameter indicating the homogeneity of the electric field. An effective pattern may be selected from the generated electrode patterns based on these computer parameters.

[0073] FIG. 3 is a diagram schematically showing an example of an embodiment of the substrate 300. In FIG. 3, a main line formed as a series of connected sub-main lines is shown, and branch lines extend from the sub-main lines. This sub-main line may correspond to the portion described with reference to FIG. 2b, but is not essential. For example, a portion as in FIG. 2b may include a plurality of sub-main lines.

[0074] In FIG. 3, a main line 301 including two sub-main lines 322 and 312 and a connection portion 311 is shown. Boxes 320 and 310 indicated by broken lines show the sub-main lines together with some branch lines. Such boxes may be selected as a unit, for example, may be repeated as a unit, or may be selected from a plurality of units, such as randomly.

[0075] The advantage of the module design in FIG. 3 is that many parameters of the branch lines can be selected simultaneously. For example, the branch lines extending on the same side of the sub-main line may have equal lengths, and the branch lines extending on the same side of the sub-main line may be parallel. Further, the number of branch lines extending from both sides of the sub-main line may be equal. These selections facilitate more effective design choices because there are fewer parameters that require control. For example, a selected sub-main line and its branch lines at a certain position can be repeated at other positions.

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

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

[0078] Changing the line spacing without stubs also reduces the diffraction effect, but it is better to combine these options. In fact, it is possible to create a substrate without using stubs. An example of such a substrate is the substrate (100) used in smart glazing, where a first electrode (110) and a second electrode (120) are applied on the same side of the substrate, and each of the first and second electrodes is arranged in a pattern across the substrate. The first electrode and the second electrode each comprise a plurality of main lines (111 - 113, 121 - 123) extending in a first direction (101) across the substrate. 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. The distance between the main lines (201, 202, 203) of the first electrode (201, 203) and the adjacent or subsequent main lines (202, 203, 204) of the second electrode (202, 204) on the substrate changes in a second direction and / or the first direction. Due to the change in line spacing, diffraction is reduced for this substrate. The substrate may be combined with the features described herein, particularly those related to the changing line spacing.

[0079] Most of the figures show main lines that are a combination of straight main lines or straight sub-main lines. However, this is not essential. For example, the main lines may be wavy, such as a sine wave shape as shown in, for example, PCT / EP2020 / 052379. Figure 4a is a schematic diagram showing an example of a substrate with a plurality of main lines, where the main lines are wavy. The main lines are connected to two or more electrodes, as shown, for example, in Figure 1a or Figure 1d. The example of Figure 4a does not include stubs, but stubs can be incorporated in a similar manner with the wavy main lines. In this situation, managing the position, angle, and length of the stubs is a major problem because the distance between the main lines is not fixed along the line. Further reduction of diffraction becomes possible by improving the ability to change the design. Figure 4b shows a schematic pattern of a substrate where the stubs are combined with non-straight main lines, such as wavy main lines. The stubs do not have to be straight either.

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

[0081] FIG. 4c is a diagram schematically showing 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 the first and second directions. These blocks contain portions of the electrode pattern, and thus a larger pattern is created by combining these blocks. For example, each block may include a plurality of sub-lines of portions of the plurality of main lines of the first electrode and a plurality of sub-lines of portions of the plurality of main lines of the second electrode. The side of the block may be, for example, between 1 mm and 10 mm. For example, the block may be 8 mm × 8 mm.

[0082] The blocks may be arranged in some regular pattern, such as a checkerboard pattern, but an irregular pattern, such as that shown in FIG. 4c, is also possible. The blocks may be rectangular. The advantage of using blocks is that, for example, beneficial blocks having a particularly low diffraction effect and / or a particularly good homogeneous electric field can be repeated a plurality of times on the substrate.

[0083] One or more of the blocks include the pattern according to the embodiment, while some blocks can also include other patterns such as a pattern without a branch line such as the pattern shown in FIG. 4a for example. Some of the main lines in the block may be straight, and some may be wavy. Some may have branch lines, and some may not, etc.

[0084] Interestingly, when dealing with linear shapes at the micro level, as shown in various examples herein, it may affect parameters such as diffraction and homogeneity, but it may also prevent the geometry of larger-scale designs and still have a significant optical impact. Therefore, it is possible to combine various electrode shapes made as blocks at different levels. From the perspective of the block structure, the blocks can be created at different levels, for example, various levels of randomization, while increasing the pattern size. Practically, it is convenient but not essential for the number of lines in the block to be a multiple of 2.

[0085] In an embodiment, the electrodes are driven by an electrical circuit that supports 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 that may be more than two on a given substrate. In an embodiment, a plurality of lines on the substrate are divided across more than two electrodes, or even more than four electrodes, or even more electrodes. It is preferable that the number of main lines for each electrode is substantially equal. For example, in an embodiment, a plurality of segments are arranged on the substrate, and each segment is controlled by at least two electrodes with respect to the substrate and at least four electrodes in the assembly of at least two substrates. By driving the corresponding electrodes, different optical effects can be configured on different segments. Although possible, the fluid does not need to be restricted to one segment. When the segments are separated from each other, different fluids can be provided to them.

[0086] FIG. 5a is a diagram schematically showing a plurality of examples of embodiments of a substrate having an electrode pattern according to an embodiment. All the embodiments shown in FIG. 5a are at a constant scale and can be enlarged up to all the electrode patterns, for example, the following interlocking patterns.

[0087] FIG. 5b is a diagram schematically showing an example of an embodiment of a substrate configured for two or three electrodes. On the left of FIG. 5b, it is shown that the main lines labeled with the letters "a" and "b" belong to the same electrode. All the lines marked with "a" are electrically connected, but this is not shown in detail in the electrode pattern shown in FIG. 5a or FIG. 5b; the same applies to the main line "b". On the right of FIG. 5b, it is shown that the main lines labeled with the letters "a", "b", and "c" belong to the same electrode. All the lines marked with the same letter are electrically connected.

[0088] FIGS. 6a and 6b are diagrams schematically showing comparative examples of two substrates. FIGS. 6c - 6d are diagrams showing examples of two embodiments. The diffraction patterns were simulated. Simulating the diffraction patterns is essentially 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 on 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-order diffraction divided by the intensity of the zero-order diffraction.

[0090] [Table 1]

[0091] Figure 6a shows, on the left side, a simple pattern consisting only of a plurality of straight main lines. These main lines are electrodes and are connected together by, for example, two electrodes of an interlocking pattern. The pattern of Figure 6b has additional perpendicular lines. It should be noted here that even if this pattern is rotated, it only rotates the diffraction pattern and thus is not helpful. Figures 6c and 6d are diagrams schematically showing examples of embodiments of the substrate. Figure 6c uses varying line spacings, varying angles, and shifting sub-main lines. Figure 6d uses a higher density of block variations along the lines, that is, a larger number of vertical blocks. Figure 6c shows three blocks and the main line changes direction three times. Figure 6d has ten blocks and its main line changes direction ten times. It should be noted that the maximum diffraction values for the values 6c and 6d are significantly lower than those of linear designs such as Figures 6a and 6b.

[0092] The pattern of Figure 6b not only has unfavorable diffraction values but also tends to generate hot spots between opposing branch lines. In the region between the tips of the opposing branch lines, the electric field is much higher than elsewhere. As a result, it leads to a non-uniform appearance in the non-transmissive state and a non-uniform transition speed.

[0093] The wavy line design of Figure 4a gives values similar to those of the design of Figure 6c, but it has been found that a design with branch lines is quicker and easier to make a beneficial choice. Furthermore, a design with branch lines provides a more uniform electric field than the wavy line design.

[0094] Two substrates according to an embodiment can be joined to form an optical modulator. This optical modulator is particularly suitable for glazing. Exemplary embodiments of the optical modulator are shown below.

[0095] Figure 7a is a diagram schematically showing an embodiment of an optical modulator 10 that can be applied in smart glazing.

[0096] Reference is made to patent application PCT / EP2020 / 052379, which is incorporated herein by reference; this application includes a beneficial design for an optical modulator, which design can be further improved, for example, by including electrodes and / or feedlines as described herein.

[0097] The optical modulator 10 can be electronically switched between a transparent state and a non-transparent state, and vice versa, or between a reflective state and a non-reflective state, and vice versa. The optical modulator 10 comprises a first substrate 11 and a second substrate 12, which are arranged opposite one another. Inside the first substrate 11, at least two electrodes are applied; electrodes 13a, 13b are shown. These at least two electrodes are collectively referred to as electrodes 13. Inside the second substrate 12, at least two electrodes are applied; electrodes 14a, 14b are shown. These at least two electrodes are collectively referred to as electrodes 14.

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

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

[0100] In one example, the substrates 11 and 12 may be light transmissive on the outside of the electrodes, with a transmissivity of >95%, for example >99%, at typically relevant wavelengths. When considering the electrodes, the transmittance may be very low, for example 70%. The term "optical" may, in the relevant case, relate to wavelengths visible to the human eye (from approximately 380 nm to approximately 750 nm), and may include a wider range of wavelengths including infrared (from approximately 750 nm to 1 μm) and ultraviolet (from approximately 10 nm to 380 nm), and may, in the relevant case, relate to sub - selections thereof. In an exemplary embodiment of the light modulator, the substrate material is selected from glass and polymers.

[0101] In other examples, one substrate, such as the lower substrate 12, may be reflective or partially reflective, and 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 drive), the particles are mostly arranged between the opposing electrodes of the two substrates so that the incident light can pass relatively unhindered through the transmissive upper substrate and the optical layer and be reflected or partially reflected on the lower substrate.

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

[0103] In one example, the modulator may be provided with a flexible polymer and the rest of the device may be provided with glass. The glass may be rigid glass or flexible glass. Optionally, a protective layer may be provided on the substrate. If more than one color is provided, more than one layer of the 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 with at least one flexible polymer. Thus, the modulator can be attached to any surface, such as using an adhesive.

[0104] The particles 30 may be configured to absorb light and thereby prevent a specific wavelength from passing through. The particles 30 may reflect light; for example, this reflection may be specular, diffusive, or intermediate. The particles may absorb some wavelengths and reflect others. The particles may also or instead 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 optical modulator, the size of the nanoparticles is 20 - 1000 nm, preferably 20 - 300 nm, and more preferably less than 200 nm. In an exemplary embodiment of the optical modulator, the nanoparticles / microparticles may optionally include a coating on the dye and preferably include a core. In an exemplary embodiment of the optical modulator, the coating of the particles is formed from a material selected from conductor materials and semiconductor materials.

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

[0107] In an exemplary embodiment of the optical modulator, the particles are charged or chargeable. For example, the charge on the particles can be from 0.1e to 10e (5*10 -7 -0.1 C / m2) per particle.

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

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

[0110] In an exemplary embodiment of the optical 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 optical modulator, the fluid contains one or more of a surfactant, an emulsifier, a polar compound, and a compound capable of forming a hydrogen bond.

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

[0113] Electrodes 13a, 13b and electrodes 14a, 14b are in fluid contact with the fluid. This fluid may be in direct or indirect contact with the electrodes. For example, the fluid may contact a second medium having 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 having a resistivity of less than 100 nΩm (at 273 K; for comparison, the ITO used typically has 105 nΩm), which has a conductivity > 1*10 at 20 °C7 (similar to S / m). In embodiments of the optical modulator, the electrodes include copper, silver, gold, aluminum, graphene, titanium, indium, and combinations thereof, preferably including copper. The electrodes may have the form of fine wires embedded in a polymer-based substrate; for example, in the form of copper fine wires.

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

[0115] The optical modulator 10 may include one or more segments, and the segments are a single optically switchable entity whose size may vary. The substrate at least partially encloses a volume that may be a segment.

[0116] The device may include a drive circuit for changing the appearance of the (individual) segments by applying an electromagnetic field. Accordingly, the appearance of the optical modulator, or the appearance of one or more parts thereof, may also be changed. For example, the segment may have an area of at least 1 mm 2 . The design enables stacking to allow for more colors; for example, for full-color applications, a stack of two or three modulators may each provide most or all of the colors.

[0117] By having one or more segments, the optical modulator becomes locally controllable; this can be beneficial depending on the application, but is not essential. For smart glazing, the optical modulator can be used with or without segments. For example, when applied in smart glazing, the transmittance or reflectivity can be locally controlled, e.g., to block a sun-patch without reducing the transmittance or reflectivity across the entire window. The segments can be relatively large, e.g., having a diameter of at least 1 mm, or at least 1 cm, etc.

[0118] In an exemplary embodiment of the optical modulator, the substrates (11, 12) are aligned and / or the electrodes (13, 14) are aligned. For example, the electrodes 13a, 13b and the electrodes 14a, 14b can be aligned to face each other. In the aligned substrates, the electrodes on different substrates are behind each other when viewed in a direction orthogonal to the substrates. When the optical modulator is removed and both substrates are arranged such that the electrodes face upwards, the electrode patterns are mirror images of each other.

[0119] Aligning the substrates can increase the maximum transmittance or reflectivity of the optical modulator, while when selecting the optical modulator for a criterion more than a range such as transmittance or reflectivity, it may be better not to align or not fully align the two substrates. The optical modulators can be stacked. For example, two stacked optical modulators can be formed from three substrates, and the middle substrate has electrodes on both of its sides. In an embodiment of the optical modulator, optionally, at least one substrate 11, 12 of the first optical modulator is the same as the substrate 11, 12 of at least one second optical modulator. Also, in the case of stacked modulators, alignment can increase the maximum transmittance or reflectivity, but can be detrimental for other considerations such as diffraction, for example.

[0120] FIG. 7b is a diagram schematically showing an example of an embodiment of the optical modulator 40. Except for including a plurality of optical layers as in the example showing a two-layer optical layer, the optical modulator 40 is the same as the optical modulator 10. There may be more than two optical layers. Each optical layer is disposed between two substrates. The optical modulator 40 can be regarded as a stack of optical modulators of two substrates as in FIG. 7a. As shown, the optical modulator 40 includes three substrates: a first substrate 41, a second substrate 42, and a third substrate 43. There is an optical layer between substrates 41 and 42, and there is an optical layer between substrates 42 and 43. These optical layers can be the same as the optical layers in the optical 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 can be electrically connected to at least 4×2 = 8 electrodes.

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

[0122] The surface of the substrate facing the other substrate can have two or more patterns, for example, as in the embodiment. For example, the external substrates 41 and 43 can receive electrodes only on the inside, while the internal substrate, for example, substrate 42, can have electrodes on both sides.

[0123] Both substrates 41 and 42 can be regarded as an embodiment of the optical modulator. Similarly, both substrates 42 and 43 can be regarded as an embodiment of the optical modulator.

[0124] FIG. 7c schematically shows an example of an embodiment of a vehicle 20 having smart glazing for a window 21. This is a particularly beneficial embodiment as during driving, the level of incident light can change frequently and rapidly. Using smart glazing in a vehicle has the advantage that the light level can be maintained at a constant level by adjusting the transmittance of the vehicle window. Furthermore, reducing the diffraction effect reduces driver distraction and thus improves safety. The vehicle 20 may comprise 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 incident light is variable, such as in buildings, offices, homes, greenhouses, skylights, etc. A skylight is a window placed in the ceiling so that sunlight can enter the room.

[0126] FIGS. 8a-8b schematically show side views of an embodiment when using a light modulator. When an electric field is applied to the electrodes on the substrate, an electric force is generated on the particles. Using this effect, the particles can move around and thus different transmission or reflection states can be caused in the light modulator. The controller can control the electric field, for example, its amplitude, frequency, and phase, etc. In an embodiment, the controller is connected to at least four electrodes: two electrodes for each substrate. However, more electrodes may be used and connected to the controller; for better fine-tuning of the gray scale and driving into a non-transmissive or non-reflective state, more than two electrodes per substrate may be used, for example. A plurality of electrodes may also be used to support a plurality of segments on the substrate.

[0127] FIG. 8a shows a light modulator to which no electric field is applied. In FIG. 8a, no electric force has yet been applied to the particles 30 floating in the fluid 15.

[0128] In the configuration shown in FIG. 8a, the conductive electrode pattern disposed on the upper substrate is completely aligned, or substantially aligned, with the conductive electrode pattern on the lower substrate. The conductive electrode pattern may be deposited on a transmissive or (partially) reflective glass substrate, or may be embedded in a plastic substrate or the like.

[0129] The alignment between the upper electrode pattern and the lower electrode pattern contributes to a wider range of achievable levels of transmissivity or reflectivity. However, alignment is not necessary since a similar effect can be obtained without alignment. Even without alignment, a similar range of transmittance or reflectance can be obtained.

[0130] It should be noted that in these examples, the upper substrate and the lower substrate are referred to as such to indicate the upper or lower substrate on the page. In glazing applications, the same substrate may be referred to as, for example, the front substrate and the rear substrate since the substrates may be aligned vertically rather than horizontally.

[0131] FIG. 8b is a diagram showing an optical modulator. For example, in instance P1, a potential +V1 is applied to each fine wire electrode on the upper substrate, while a negative voltage, for example -V1, is applied to each fine wire electrode on the lower substrate. As a result, in this case, the same positive potential is applied to all electrodes 13, and the same negative potential is applied to electrodes 14. Due to this potential difference, negatively charged particles are flowed near the electrodes on the upper substrate, where the particles are substantially aligned with the upper electrodes. As a result, when both the upper substrate and the lower substrate are transmissive, the transmittance of the optical modulator 10 increases. Similarly, for example, when the upper substrate is transmissive and the lower substrate is reflective, the reflectance of the optical modulator 10 increases. When the solution contains positively charged particles, the positively charged particles flow near the electrodes on the lower substrate, and those particles are substantially aligned with the lower electrodes.

[0132] In the second instance P2 in the ON state, in contrast to instance P1, when the voltages of the upper electrode and the lower electrode are reversed, a similar transmittance or reflectance can be achieved. In instance P2, the voltage of each electrode on the upper substrate supplies a negative potential -V1 there, and the voltage of the aligned electrodes on the lower substrate supplies a positive potential. This state is similar to the state shown in FIG. 8b, but the upper substrate and the lower substrate are reversed. Also in this configuration, the transmittance or reflectance of the optical modulator 10 is high.

[0133] Interestingly, by switching the positive potential of the electrode on the upper substrate (and the negative potential at electrode 14) as shown, for example, as electrode 13 in FIG. 8b, and the positive potential at the electrode on the lower substrate as shown, for example, as electrode 14 in FIG. 8b, the transmittance or reflectance can be maintained while reducing the corrosion damage to the electrodes. This alternating electric field can be achieved by applying an alternating potential to the upper and lower electrodes.

[0134] Applying a waveform is optional, but it is an effective means of increasing the life of the optical modulator by reducing corrosion. Corrosion can occur, for example, when using copper electrodes because copper ions dissolve in the ionic fluid on one substrate, flow to the electrodes of the opposing substrate, and deposit there. By applying a waveform, the direction of copper ion transport is frequently reversed, thus reducing the corrosion damage. Between the two instances P1 and P2, the corrosion current between the two substrates is balanced, or almost, for example, >95% balanced. For example, when the corrosion rate of the electrodes on the upper plate occurs, there is an equal deposition of copper at the lower electrodes between each time instance P1, and the same is true for the reverse case in instance P2. Thus, particles continuously migrate or transfer between the upper and lower electrodes, and the optical modulator or smart window is always in the ON state, while the dynamic electrolytic current between the upper and lower electrodes becomes constant, and thus there is no net loss, or negligible net loss, of the electrode material on the upper and lower substrates.

[0135] FIG. 8c is a diagram showing how a transmittance or reflectance reduction state can be obtained. An alternating voltage is applied on the same substrate. For example, in an embodiment, as shown in FIG. 8c, a potential +V2 is applied to the first electrode, and the next adjacent electrode has the opposite potential -V2, and so on. This can be obtained by applying the potential +V2 to electrode 13a and the opposite potential -V2 to electrode 13b. On the opposing substrate, the potential +V2 may be applied to electrode 14a and the opposite potential -V2 may be applied to electrode 14b. For example, these electrodes may be arranged such that the electrodes on the substrate are aligned; the electrodes on the upper substrate have electrodes facing them on the lower substrate, and vice versa. For example, in order to reduce the transmittance or reflectance, the opposing electrodes may receive the same potential, while the adjacent electrodes receive opposite potentials. FIG. 8c shows an embodiment in which four electrodes are denoted by reference numerals 13a, 13b, 14a, and 14b, and the rest of the electrodes are continuously alternating.

[0136] By using this AC driving cycle between the upper substrate and the lower substrate, an electric field in the diagonal direction and an electric field in the horizontal direction are generated between the two substrates, thereby causing accidental diffusion of particles, thereby creating a closed state of the optical modulator. As a result of this configuration, the particles migrate in the diagonal direction and the horizontal direction between the upper substrate and the lower substrate, and the diffusion of the particles into the visible aperture of the optical modulator contributes to the closed and opaque state of the optical modulator.

[0137] For the transmission state shown in FIG. 8b, a waveform can be applied to the electrodes such that, for example, the electrodes shown in FIG. 8b having a positive potential become negative, and vice versa. As in FIG. 8b, for example, when a waveform is applied between electrode 13a and electrode 13b and between electrode 14a and electrode 14b, the corrosion damage to the electrodes is reduced.

[0138] The AC driving cycle can be implemented by using an interlocking line configuration that combines the configurations of the upper electrode and the lower electrode shown in plan views such as FIGS. 5, 6a - 6d.

[0139] The degree to which the transmittance or reflectance increases or decreases in FIGS. 8b and 8c depends on the voltage and frequency differences. By changing the voltage difference, the amount by which the transmittance or reflectance increases and decreases, respectively, is controlled. For example, a curve representing light transmittance versus voltage may be determined, for example, measured. To obtain a specific level of light transmittance, for example, a specific transmittance, for example, a specific grayscale level, a corresponding voltage, for example, an AC voltage, may be applied. By interpolating signals in a transmitted or non-transmitted state, a level between transmission and non-transmission can be obtained. Similarly, a curve representing light reflectance versus voltage may be determined, for example, measured. To obtain a specific level of reflectance, a corresponding voltage, for example, an AC voltage, may be applied. By interpolating signals in a reflected or non-reflected state, a level between reflection and non-reflection can be obtained.

[0140] For the optical modulator, different electrode patterns can be used. Each electrode pattern can provide a range of grayscale levels, for example, levels of transmissivity or reflectivity, that the optical modulator can obtain. However, the specific range of grayscale for any particular electrode pattern can be different from other electrode patterns. That is, different patterns give an increase in transmittance or reflectance or an increase in non-transparency, but the exact response to the drive signal depends on many factors including the specific pattern used. Changes in the optical properties of the optical modulator can have a fine resolution of less than, for example, 1 mm. It should be noted that pixelation of the optical modulator is not necessary to achieve different optical patterns, for example, a visible logo in the optical modulator.

[0141] This effect can be used to embed a visible image in the optical modulator by locally changing the electrode pattern on the substrate of the optical modulator. For example, for different electrode patterns, there may be a locally grayscale with a permanent offset of the grayscale relative to each other. For example, by locally changing the electrode pattern or its pitch, the maximum transmittance or reflectance can be changed.

[0142] As a result, the area on the optical modulator has different intensities of grayscale, for example different grayscale levels or different intensities of coloring. However, this area can have the same color point. In an embodiment, it can be switched together with the rest of the window at different ratios. For example, even when the same voltage is applied to the electrodes in two different areas, different transmission states, for example different transmittance levels, are generated due to different electrode patterns. For example, the curve representing transmittance versus voltage may be shifted. For example, when the voltage control is changed in the same way in both areas, the light transmittance may change in both areas, but by different amounts. The area can further reduce the response to the drive signal by reducing the density of the electrodes; in particular, for example, by not applying electrodes in the area, the area can be formed so as not to switch at all.

[0143] This effect can be used to embed a logo in the optical modulator. For example, FIG. 9a is a diagram schematically showing an example of an embodiment of a logo and a grid. 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 from the second set of grid squares can be used. FIG. 9b is a diagram schematically showing an example of an embodiment of a substrate. In the area indicated by the first grid square, a different electrode pattern from the area indicated by the second grid square may be embedded in the first and second substrates, such as the substrate as shown in FIG. 7a. As shown in FIG. 9b, the two areas have different transmittances.

[0144] Figures 9c - 9d are diagrams schematically showing examples of embodiments of the optical modulator. In Figure 9c, the substrate is in a non - transmissive configuration, and in the area indicated by the logo, it is shown that the electrode pattern is configured to make the optical modulator inefficient and dark. In Figure 9d, it is shown that the same substrate is in a more transmissive configuration. It should be noted that although at different ratios, the transmittance is increasing in both the logo area and the area outside the logo. Even if the transmittance of those areas is close to each other here, the area indicated by the logo is still visible in Figure 9d.

[0145] Interestingly, this effect may only be achieved by different patterning, for example, by changing the pitch and / or design of the electrodes. Changing the waveform / current / voltage / power to this area is not necessary compared to other areas.

[0146] Especially in smart glazing, embedding an image in the optical modulator has many applications. For example, content such as logos, brands, etc. may be embedded. Textures may be embedded in the glazing. Contrast gradients may be embedded in the glazing. Other options include emergency signals such as arrows.

[0147] For example, in the windows of stores / restaurants: completely black windows may indicate that the store is out of business, while a logo or any other designated design is visible when the store is open. This pattern may be a logo or the like, but this is not essential. The embedded image may also be a pattern that provides sufficient light inside while preventing passers - by from seeing inside the window. In particular, the embedded image does not necessarily need to contain a readable message. In car windows, when the vehicle is switched to the OFF state, for example, when parked, the glazing may become completely dark, while when the vehicle is switched to the ON state, a logo, for example, the manufacturer's logo appears.

[0148] By adjusting the design parameters, a certain local optical difference becomes visible compared to the background without a change in the electrical driving force. The parameters of the electrode pattern that affect the optical performance are: - Electrode line spacing - Electrode line thickness - Electrode line shape - Electrode line direction - Local variations in the cell gap, such as the distance between substrates - Distribution of the length of the branch lines including.

[0149] For example, the electrode line spacing, thickness, shape, and direction act on the local transmittance level and response time; the electrode line spacing / width locally affects the diffraction level that can also enable a specific local optical difference. Changes in the cell gap change the dark state level and, as a result, also change the maximum transmittance or reflectance and the response time. Another option is to vary the diffraction effect between two areas. For example, one area, such as most of the glazing, may have an electrode pattern with a low diffraction effect, while an embedded image may have an electrode pattern with a planned high diffraction effect.

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

[0151] For example, the electrode material may be copper, aluminum, gold, indium tin oxide (ITO), etc. Cu / Al is reflective, while ITO is transmissive, so using different electrode materials can result in different appearances regardless of voltage driving. Similarly, different materials with different resistances produce different electric fields. For example, ITO has a smaller electric field even when driven at the same voltage.

[0152] Another way to obtain a change in transmittance or reflectance is by locally varying a spacer that can be applied between a first substrate and a second substrate. 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 may be different. In an embodiment, the density of the spacers may be increased by a factor of 1000 or decreased, giving a significantly different appearance. An increase of less than a factor of 1000 is also possible. The spacers can also be configured to intentionally vary the distance between the substrates and thus change their appearance.

[0153] Various options for locally varying the appearance of an area of a light modulator without changing the drive in that area may be applied to a light modulator having a single layer, e.g., a single fluid layer, e.g., a light modulator having two substrates; but may also be applied to a light modulator having multiple fluid layers and multiple layers of more than two substrates. The latter can be used to generate multiple colors.

[0154] The pattern in which the first and second electrodes are arranged is subdivided into a plurality of parts. For example, due to different electrode patterns, there may be two parts each having different optical properties; or there may be a plurality of parts. For example, this can be used to apply an image having not only black and white but also multiple levels of gray.

[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 includes 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, and each of the first and second electrodes includes a plurality of main lines extending in a first direction across the substrate. The plurality of main lines of the first and second electrodes are alternately arranged 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, resulting in different maximum transmittance or reflectance, or chroma.

[0156] Regardless of the presence or absence of the branch lines, a substrate with such a logo embedded therein, or an optical modulator including such a substrate, can be combined with other features described herein.

[0157] FIG. 10 is a diagram schematically showing an example of an embodiment of a method for controlling an optical modulator according to an embodiment. Method 500 can be implemented by a computer. Method 500 includes - selecting an alternating current of one of a plurality of maximum amplitudes corresponding to one of a plurality of levels of transmissivity in the optical modulator (510), - applying an alternating current to the electrodes to obtain an electromagnetic field between the electrodes that causes an electrophoretic movement of particles towards or from the electrodes (520).

[0158] As will be apparent to those skilled in the art, many different ways of performing this method are possible. For example, the steps may be performed in the order shown, but the order of the steps can be changed, and some steps may be performed in parallel. Further, other method steps may be inserted between the 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. Further, a given step may not be completed entirely before the next step is started.

[0159] Driving the electrode may use a signal having a selected maximum amplitude corresponding to one of a plurality of levels of transmissivity or reflectivity in the optical modulator. This signal may be an alternating current or an alternating voltage.

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

[0161] The subject matter of the present disclosure is also understood to extend to a computer program, particularly a computer program carried on or in a carrier configured to put the subject matter of the present disclosure into practice. The program can be in any suitable form, such as source code, object code, intermediate source in the code, and object code in a partially compiled form, or any other suitable form used in the implementation of the embodiments of the method. Embodiments related to computer program products include computer-executable instructions corresponding to each of at least one of the processing steps of the described methods. These instructions may be subdivided into subroutines and / or stored in one or more files that can be statically or dynamically linked. Other embodiments related to computer program products include computer-executable instructions corresponding to each of at least one of the devices, units, and / or parts of the described systems or products.

[0162] FIG. 11a shows a computer-readable medium 1000 having a writable portion 1010 that includes a computer program 1020, which, according to an embodiment, includes instructions for causing a processor system to perform a light modulator method. For example, the processor system may be connected to a light modulator panel. The computer program 1020 can 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 embodiments are also conceivable. Further, although the computer-readable medium 1000 is shown here as an optical disk, it will be understood that the computer-readable medium 1000 can be any suitable computer-readable medium, such as a hard disk, solid-state memory, flash memory, etc., and can be non-recordable or recordable. The computer program 1020 includes instructions for causing the processor system to perform the 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. This processor system includes one or more integrated circuits 1110. The architecture of the one or more integrated circuits 1110 is schematically shown in FIG. 11b. Circuit 1110 includes a processing unit 1120, such as a CPU, to execute a method according to an embodiment and / or to run computer program components that implement its modules or units. Circuit 1110 includes a memory 1122 for storing programming code, data, etc. A portion of the memory 1122 may be read-only. Circuit 1110 may include a communication element 1126, such as an antenna, a connector, or both. Circuit 1110 may include an application-specific integrated circuit 1124 to perform some or all of the processing defined in the present method. The processor 1120, the memory 1122, the application-specific IC 1124, and the communication element 1126 may be connected to each other via an interconnect 1130, such as a bus. The processor system 1110 may be configured for contact and / or non-contact communication using an antenna and / or a connector, respectively.

[0164] For example, in an embodiment, the processor system 1140, such as the present device, may include a processor circuit and a memory circuit, and 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 such as a flash memory. The memory circuit may be a volatile memory such as an SRAM memory. In the latter case, the device may include a non-volatile software interface such as a hard drive and a network interface configured to provide software, for example.

[0165] For example, a controller for an optical modulator that controls the voltage applied to an electrode may include a processor circuit, or alternatively, may also include a state machine.

[0166] Figs. 12-37 schematically show examples of embodiments of an optical modulator. In these figures, the voltages that can be applied to the electrodes are indicated using voltage references V1, V2, … to indicate that the voltage can be applied to the electrode. The voltages indicated by different voltage references are typically different, but they may be equal. The driving of the electrodes may use a signal having a selected maximum amplitude. Using different voltages for one electrode, or some electrodes, or all electrodes results in a visual difference in the panel, and in particular, different optical characteristics can be obtained depending on specific, for example, different transmittances. For example, the signal amplitude can be selected from a plurality of maximum amplitudes to achieve one of a plurality of transmittances. These signals may be alternating current or alternating voltage.

[0167] A positive or negative sign indicates whether the voltage is positive or negative with respect to the zero voltage reference. 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 (except for the sign) to account for manufacturing variations, such as slightly different electrodes, non-flat substrates, etc. As an example, the various voltage references may be different to create intermediate transmittances, such as various grays, or various colors, or color intensities. As an example, intermediate voltages can be used to facilitate the dispersion or collection of particles. The use of different voltage references is beneficial, but useful examples of optical modulators can still be obtained by selecting all or some of the voltage references to be equal (except for the sign).

[0169] Typically, the electrodes are driven to DC neutral, for example, by applying an AC signal to those electrodes. In that regard, the voltage reference can be considered as the maximum amplitude of the AC signal, and the positive and negative signs indicate the phase of the signal.

[0170] The voltage sign (positive / negative indication) is thus only for a specific period; the voltage sign for each electrode can be inverted for the next period. The figures are not to an exact 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 figure shows an optical modulator comprising a first substrate and a second substrate, with an optical layer therebetween. A plurality of electrodes are applied inside them, each of which comprises a plurality of main lines. In the figure, the first and second substrates are also referred to as upper and lower for clarity. Although not stated, the substrates may be in any position, and the upper and lower may be, for example, the front and the rear. Expansion functions may be applied, but the electrodes in these figures do not show expansion functions such as branch lines.

[0172] The controller can be connected to the shown optical modulator to control the voltage created on the electrodes, as indicated, for example, by the voltage reference.

[0173] Note that, for example, many of the improvements described herein, such as having a branch line and having more than two electrodes on a substrate, are particularly beneficial when combined; for example, the branch line reduces diffraction, but it should be noted that this effect is increased when multiple electrodes reduce the curtain effect. However, these extended functions as described herein below or elsewhere are also, for example, indecently beneficial without a controller configured to obtain one of multiple levels of transmissivity or reflectivity in a modulator by using one of multiple alternating currents of maximum amplitudes. The following embodiments can be configured for a controller that cannot be driven using alternating currents of different maximum amplitudes by selecting voltages shown to be equal by a voltage reference.

[0174] FIGS. 12-15 schematically show examples of embodiments of a modulator having two electrodes applied to each substrate.

[0175] Having at least four independent electrodes, for example, when 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 described above, the potential level can be modulated for each electrode. By using a single potential reference, a simplified modulator can be obtained.

[0176] FIG. 12 shows an example of driving a modulator to increase transmittance.

[0177] FIG. 13 shows an example of driving a modulator to decrease transmittance. It should be noted that the diagonal lines of force are created to increase the dispersion rate of the particles. Further, the particles disperse more towards the middle of the modulator, which reduces the curtain effect.

[0178] Figures 13 and 14 are diagrams showing two different ways of driving towards a darker state. Figure 14 is a diagram showing an example of driving a light modulator where both the vertical electric field and the horizontal electric field are increased. Which of the vertical electric field and the horizontal electric field is more powerful for driving the dye depends on the design, for example, the dimensions of the cell pitch and the line pitch. When the distance between the electrodes is reduced and the particles move towards the electric field region where the electric field becomes the strongest, the electric field becomes stronger. If the difference in the electric field between the vertical electric field and the horizontal electric field in this case is not powerful enough, the light modulator demonstrates an intermediate open state when the design is homogeneous across the substrate.

[0179] When the design changes the light modulator and the distance between the electrodes within the same substrate and the distance between the substrates are not constant across the light modulator, locally, the highest electric field region along which the charged particles aggregate changes, and as a result, an optical difference is obtained. In some areas, the transmittance of the light modulator can be increased, while in other areas, the transmittance of the light modulator can be lower even with uniform electrical driving. This effect is less achievable with other driving methods, such as the method shown in Figure 13. This effect can be used, for example, to embed a logo in the light modulator.

[0180] Figure 15 is a diagram schematically showing an example of using an alternating current with one of the maximum amplitudes among a plurality of maximum amplitudes. The first electrode on the upper substrate is driven using a reference voltage +V, while the second electrode on the upper substrate is driven using a reference voltage +V / 2. The opposing electrodes on the lower electrode are driven using -V / 2 and -V respectively. It should be noted that the voltage difference between the opposing electrodes is + / −1.5V, while the voltage difference between adjacent electrodes is + / −0.5V. As a result, most of the particles react to the vertical electric field and settle to increase the transmittance, but the effect becomes smaller.

[0181] Figures 16 and 17 schematically show an example of an embodiment in which one substrate has two electrodes and the other has three electrodes. In the embodiment, at least three electrodes are applied to at least one of the first substrate and the second substrate, and at least two electrodes are applied to the other substrate.

[0182] When additional electrodes are available, additional combinations of voltages can be obtained. This results in, for example, more control for grayscale. For example, in the case of five electrodes instead of four electrodes, an addressing mode that is not achievable in a four - electrode system becomes possible.

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

[0184] The advantage of having at least three electrodes on the substrate is that it is possible to bring those electrodes closer together without reducing the maximum transmittance or reflectance. For example, in the embodiment, the electrodes on the substrate having at least three electrodes can be spaced 35 microns apart, while on the opposing substrate having, for example, two electrodes, the electrodes can be spaced 70 microns apart. These are exemplary numbers; the actual numbers can be changed depending on the requirements of the application.

[0185] Electrodes spaced closer together result in a stronger electric field, and thus faster closing, and therefore a reduced curtain effect. On the other hand, when open, if the additional electrodes are configured not to attract particles, the loss of maximum transmittance or reflectance is minimal.

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

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

[0188] Figures 16 and 17 show an example that promotes reducing the transmittance.

[0189] Figures 18 - 19 are diagrams schematically showing an example of an embodiment of an optical modulator having three electrodes on each substrate.

[0190] Having at least three electrodes on each side increases the advantages of having five electrodes. Since not all electrodes are necessary to open the device, it is possible to bring the electrodes closer on both sides without reducing the transmittance. Further, having three electrodes on each substrate allows six electrodes to be symmetrically arranged.

[0191] Figures 20 - 23 schematically show an example of an embodiment of an optical modulator having four electrodes on one substrate and two electrodes on the other substrate. As the number of electrodes increases, further modulation of the transmittance becomes possible and is controlled not only by particle movement but also by design. As shown in Figure 20, the optical modulation area can be set to spread particles in the visible area, while other parts can be set to concentrate particles within a vertical electric field. This enables grayscale by design control. Figures 21, 22, and 23 show other examples of the relationship of potentials across two electrodes and four electrodes for modulating the grayscale.

[0192] Figs. 24 to 29 schematically show examples of embodiments of a light modulator having four electrodes on each substrate. With these examples, even further control of grayscale becomes possible.

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

[0194] The light modulator shown in Fig. 30 has additional secondary electrodes running parallel to the primary electrodes. For example, the primary electrodes may be main lines or branch lines, etc. In Fig. 30, one primary electrode is indicated by reference numeral 3001, and one secondary electrode is indicated by reference numeral 3002. As shown in the figure, the secondary electrodes run along each of the primary electrodes, but this is not essential.

[0195] In the embodiment, the secondary electrodes are connected to the primary electrodes through the semiconductor layer, and the secondary electrodes are electrically connected to the primary electrode lines by the semiconductor layer, whereby only a transmission current exceeding the threshold voltage is possible on the primary electrodes. Therefore, the voltage switch can be handled by the potential.

[0196] Accordingly, the primary electrodes or portions thereof can be locally interconnected to the secondary electrodes. By interfacing with the semiconductor material layer, when the minimum potential is applied on the electrodes, the transmissive electrodes see only the potential. Thereby, a voltage switch handled by the potential can be created on the surface. The secondary electrodes may be transmissive. The second electrodes may be the same size or similar size as the primary electrodes, or much larger.

[0197] In the embodiment, the secondary electrodes include a capacitor configured to locally hold charges. This can be used for gain in power. A semiconductor layer is not necessary to form an electrode extended as a capacitor.

[0198] In the embodiment, the secondary electrodes include a photovoltaic semiconductor material, and the secondary electrodes supply power to the primary electrode lines.

[0199] Figures 31 - 33 schematically show examples of embodiments of a substrate having two electrodes that extend in two dimensions but are offset in a third dimension. These figures show top views. The two electrodes are each disposed in a plane, but their planes are offset relative to each other. For example, the electrodes may be etched.

[0200] An insulator may be disposed between the first electrode and the second electrode where the first electrode and the second electrode cross to avoid electrical connection. Thus, this structure improves the reliability of the electrodes because each electrode locally overlaps. Thus, it is possible to connect the electrode lines not only in an interlocking manner but also in a mesh-like manner. If the electrodes do not overlap, they will remain in contact with the fluid.

[0201] This structure promotes the fabrication of the interlocked electrodes and their reliability. Also, it enables the locally creating of a new electric field area, for example, using some permeable electrodes, in order to spread particles, such as dyes, better over the surface. Also, it enables the locally creating of a new electric field area using some permeable electrodes in order to spread particles, such as dyes, better over the surface.

[0202] The interlocking pattern of the electrodes on each substrate enables the light modulator to be set in a particle-dispersed state (typically, the dark state). An electric field parallel to the substrate provides a high level of homogeneity. The distribution of the electric field along the vertical axis, i.e., the axis from substrate to substrate, promotes the concentration of particles by the lines of force and can be considered less homogeneous, and the physical inhomogeneity can be utilized to more easily create a gray scale.

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

[0204] Offsetting two electrode patterns at an angle may be applied within opposing substrate-to-substrate, or may be applied 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 interlocking electrodes may be applied to two parallel substrates, in which case the main lines in the two substrates are not parallel but form an angle with respect to each other.

[0205] FIG. 34 is a diagram schematically showing an example of an embodiment of an optical modulator, in which 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 with respect to each other.

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

[0207] Specific alignment defects can be applied either globally or only locally to the device. For example, specific alignment defects can be made to act on the edges to prevent unwanted particle movement towards the edges, also known as the dye migration effect. In an embodiment, the alignment at specific locations can be corrected to better accommodate future bending of the optical modulator. By combining non-aligned patterns with aligned patterns between substrates, optical effects such as diffraction and / or parallax can be improved.

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

[0209] FIG. 35 is a diagram schematically showing an example of an embodiment of an optical modulator having four electrodes on each substrate. In an embodiment, different materials may be combined for the electrodes to reduce parallax.

[0210] For example, on each substrate, one of the two electrodes can be formed of metal or a permeable material (e.g., ITO), or can have different optical indices. The electrodes on the opposing substrates are formed from other types of materials; for example, the permeable material can be the opposite non-permeable material.

[0211] For example, in the 8-electrode system shown in FIG. 35, the electrodes surrounded by circles can be formed of a permeable material (e.g., ITO), and the other electrodes can be formed of metal (e.g., copper) and be non-permeable. This reduces the influence of the alignment tolerance regarding parallax even when the horizontal electrode shape design requires perfect alignment between the lower substrate and the upper substrate. Manufacturing variations also have little effect.

[0212] FIGS. 36-37 are diagrams schematically showing examples of embodiments of a light modulator having different geometries across substrates. For example, the electrode geometry can be different across at least one of the first and second substrates, for example, one or more of the thickness, width, shape, area, and volume of the electrodes can be different.

[0213] Using 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, and examples can be a rectangle with rounded corners or a non-rounded rectangle, a triangle, a trapezoid, etc.

[0215] FIG. 36 shows an example of electrodes on substrates having different heights. FIG. 36 also shows an example of opposing electrodes on different substrates having different heights.

[0216] FIG. 37 shows an example of electrodes on substrates having different shapes. FIG. 36 also shows an example of opposing electrodes on different substrates having different shapes.

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

[0218] The following numbered items include intended non - limiting examples:

[0219] 1. An optical modulator comprising: - A first substrate and a second substrate, the inner sides of which are arranged to face each other, and a plurality of electrodes (110, 120) are applied to the inner sides of each of the first and second substrates, and each of the plurality of electrodes is arranged in a pattern across the substrate, and each of the plurality of electrodes comprises: - A plurality of main lines extending in a first direction across the substrate, and the plurality of main lines of the plurality of electrodes are arranged alternately with respect to each other on the substrate, the first substrate and the second substrate comprising the plurality of main lines; - An optical layer between the first substrate and the second substrate, comprising: - A fluid containing particles, the particles being charged or chargeable, the optical layer; - A controller configured to apply a potential to the plurality of electrodes to obtain an electromagnetic field between the plurality of electrodes that causes electrophoretic movement of the particles towards or from one of the plurality of electrodes, thereby generating modulation of the optical properties of the optical modulator, and configured to obtain one of a plurality of levels of transmissivity or reflectivity in the optical modulator by using an alternating current or voltage of one of the plurality of maximum amplitudes, the controller An optical modulator comprising.

[0220] 2. The optical modulator according to item 1, wherein the controller is configured to apply a potential difference between subsequent electrodes on the same substrate and, at the same time, apply a potential difference between opposing electrodes on the opposing substrate.

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

[0222] 4. The optical modulator according to any one of items 1 to 3, wherein the distance between subsequent main lines of a plurality of electrodes on the first substrate is greater than the distance between subsequent main lines of a plurality of electrodes on the second substrate.

[0223] 5. An optical modulator having a transmission state and a non-transmission state, or a reflection state and a non-reflection state, - By creating an alternating voltage on at least one of the first and second substrates, it is switched to a non-transmission state or a non-reflection state, and an alternating current is applied between at least the first electrode and the second electrode on the first substrate and / or between the first electrode and the second electrode on the second substrate. - By creating an alternating voltage between the first substrate and the second substrate, it is switched to a transmission state or a reflection state, and an alternating current is applied between the first electrode on the first substrate and the first electrode on the second substrate, and / or between the second electrode on the first substrate and the second electrode on the second substrate. The optical modulator according to any one of items 1 to 4, which is configured as described above.

[0224] 6. A plurality of electrodes on at least one substrate of each substrate include at least a first electrode and a second electrode, and the first electrode and the second electrode each: - 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 alternately arranged with respect to each other on the substrate. - A plurality of branch lines extending from the main lines into the area between the main lines, and the branch lines extending into the area between the first main line and the second main line of the first electrode and the second electrode extend alternately from the first and second main lines and extend into the same area. At least one of the two subsequent branch lines extends at least half along a second direction orthogonal to the first direction measured across the area. The optical modulator according to any one of items 1 to 5, which comprises a plurality of branch lines.

[0225] 7. The optical modulator according to any one of items 1 to 6, wherein two subsequent branch lines extending into the same area between the first main line and the second main line overlap in the second direction when projected in the first direction.

[0226] 8. The optical modulator according to any one of items 1 to 7, wherein two subsequent branch lines extending into the same area between the first main line and the second main line have different lengths, and the longer branch line is at least 5% longer than the shorter branch line.

[0227] 9. The optical modulator according to any one of items 1 to 8, wherein the distance between the main line on the substrate of the first electrode and the second electrode and the subsequent main line changes in the second direction and / or the first direction.

[0228] 10. The distance between the main lines - alternately increases towards the maximum distance and decreases towards the minimum distance, and / or - increases or decreases by a random amount within the maximum distance and the minimum distance, and / or - a series of distances in the second direction between the main lines across the substrate change randomly, and the sum of the distances is between the minimum total distance and the maximum total distance, The optical modulator according to any one of items 1 to 9.

[0229] 11. The main line and the branch line extending from the main line are formed as a series of connected sub-main lines where the branch line extends, and the series of sub-main lines are connected to form the main line, - the branch lines extending on the same side of the sub-main line have equal lengths, and / or - the branch lines extending on the same side of the sub-main line are parallel, and / or - the number of branch lines extending from both sides of the sub-main line is equal, The optical modulator according to any one of items 1 to 10.

[0230] 12. The branch lines extending on the same side of the sub-main line and the branch lines extending from the subsequent sub-main lines of the same main line - have different lengths, and / or - form an angle different from the first direction and / or - having a different number of branch lines extending from the side of the secondary main line, The optical modulator according to claim 11.

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

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

[0233] 15. The pattern in which the first and second electrodes are arranged is subdivided into a set of blocks extending in the first and second directions across the substrate, and each block includes a plurality of sub-lines of a part of the plurality of main lines of the first electrode and a plurality of sub-lines of a part of the plurality of main lines of the second electrode, and at least one of the blocks is repeated a plurality of times on the substrate. The optical modulator according to any one of claims 1 to 14.

[0234] 16. - In a part of the block, the electrode of the secondary main line has a plurality of branch lines, and in a part of the block, the electrode does not have a plurality of branch lines, and / or - In a part of the block, the secondary main line is straight, and in a part of the block, the secondary main line is wavy, The optical modulator according to any one of claims 1 to 15.

[0235] 17. The pattern in which the electrodes are arranged is subdivided into a plurality of 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 plurality of parts, generating an optical effect. The optical modulator according to any one of claims 1 to 16.

[0236] 18. The optical modulator according to any one of claims 1 to 17, wherein the electrode geometry selected from the group consisting of thickness, width, shape, area, and volume is different across at least one of the first and second substrates.

[0237] 19. The primary electrode is 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 semiconductor layer, the secondary electrode is electrically connected to the primary electrode line by the semiconductor layer, whereby only a transmission current exceeding the threshold voltage on the primary electrode is possible, and / or - the secondary electrode is transparent, and / or - the secondary electrode comprises a capacitor configured to locally hold charge, and / or - the secondary electrode contains a photovoltaic semiconductor material, and the secondary electrode supplies power to the primary electrode line, The optical modulator according to any one of claims 1 to 18.

[0238] 20. The optical modulator according to any one of claims 1 to 19, wherein a plurality of electrodes extend two-dimensionally across the substrate, and in a third dimension, at least a first electrode among the plurality of electrodes is set apart from at least a second electrode among the plurality of electrodes, and optionally, an insulator is disposed between the first electrode and the second electrode.

[0239] 21. The optical modulator according to any one of claims 1 to 20, wherein the electrodes on the first substrate are arranged in at least a partially identical pattern as the second electrodes on the second substrate, and the patterns of the first and 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 the same side of the substrate, each of the plurality of electrodes is arranged in a pattern across the substrate, and at least a first electrode and a second electrode among the plurality of electrodes are each: - a plurality of main lines extending in a first direction across the substrate, wherein the plurality of main lines of the first and second electrodes are alternately arranged relative to each other on the substrate; - A plurality of branch lines extending from a main line into an area between main lines, wherein the branch lines extending into the area between the first main line and the second main line of the first electrode and the second electrode extend 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 as measured along a second direction orthogonal to the first direction across the area, and the substrate comprises a plurality of branch lines.

[0241] 23. An optical modulator method, providing an optical modulator, the optical modulator comprising: - a first substrate and a second substrate, the inner sides of which are arranged to face each other, a plurality of electrodes are applied to the inner sides of each of the first and second substrates, each of the plurality of electrodes is arranged in a pattern across the substrate, and each of the plurality of electrodes comprises: - a plurality of main lines extending in a first direction across the substrate, and the plurality of main lines of the plurality of electrodes are arranged alternately with respect to each other on the substrate, and the first substrate and the second substrate each comprise a plurality of main lines; - an optical layer between the first substrate and the second substrate, the optical layer comprising: - a fluid containing particles, the particles being charged or chargeable, and the optical layer comprising the fluid; selecting an alternating current or an alternating voltage of one of a plurality of maximum amplitudes corresponding to one of a plurality of levels of transmissivity or reflectivity in the optical modulator, and applying an alternating current to the electrodes to obtain an electromagnetic field between the electrodes that causes electrophoretic movement of the particles towards or away from the electrodes, thereby generating modulation of the optical properties of the optical modulator The optical modulator method includes.

[0242] 23. A temporary or non-temporary computer-readable medium including data representing instructions that, when executed by a processor system, cause the processor system to perform the method according to item 22.

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

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

[0245] In the claims, references in parentheses refer to reference signs in the drawings of the exemplary embodiments or to the formulas of the embodiments, and thus make the claims easier to understand. These references shall not be construed as limiting the claims.

Claims

Claim 1 An optical modulator comprising - a first substrate and a second substrate, the inner sides of which are arranged to face each other, and a plurality of electrodes (110, 120) are applied to the inner sides of each of the first and second substrates, and the plurality of electrodes on at least one of the substrates include at least a first electrode and a second electrode, and each of the plurality of electrodes is arranged in a pattern across the substrate, and the plurality of electrodes each - include a plurality of main lines extending in a first direction across the substrate, and the plurality of main lines of the plurality of electrodes are arranged alternately with respect to each other on the substrate, and the first electrode and the second electrode each - include a plurality of branch lines extending from the main lines into the area between the main lines, and the branch lines extending into the area between the first main line and the second main line of the first electrode and the second electrode extend alternately from the first and second main lines, and at least one of the two subsequent branch lines extending into the same area extends at least half as measured along a second direction orthogonal to the first direction across the area, and the first substrate and the second substrate include a plurality of branch lines - an optical layer between the first substrate and the second substrate - an optical layer comprising a fluid containing particles, the particles being charged or chargeable - a controller configured to generate modulation of the optical properties of the optical modulator by applying a potential to the plurality of electrodes to obtain an electromagnetic field between the plurality of electrodes that causes electrophoretic movement of the particles towards or from one of the plurality of electrodes, and is configured to obtain one of a plurality of levels of transmissivity or reflectivity in the optical modulator by using an alternating current or alternating voltage of one of the plurality of maximum amplitudes An optical modulator comprising the same Claim 2 The optical modulator according to 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 the opposing substrate Claim 3 - at least three electrodes are applied to at least one of the first substrate and the second substrate, or - at least three electrodes are applied to both the first substrate and the second substrate The optical modulator according to claim 1 or 2 Claim 4 The optical modulator according to any one of claims 1 to 3, wherein the distance between subsequent main lines of a plurality of electrodes on the first substrate is greater than the distance between subsequent main lines of a plurality of electrodes on the second substrate.

5. An optical modulator having a transmission state and a non-transmission state, or a reflection state and a non-reflection state, - By creating an alternating voltage on at least one of the first and second substrates, switching to a non-transmission state or a non-reflection state, and applying an alternating current between at least the first electrode and the second electrode on the first substrate and / or between the first electrode and the second electrode on the second substrate, - By creating an alternating voltage between the first substrate and the second substrate, switching to a transmission state or a reflection state, and applying an alternating current between the first electrode on the first substrate and the first electrode on the second substrate, and / or between the second electrode on the first substrate and the second electrode on the second substrate The optical modulator according to any one of claims 1 to 4, configured as described above.

6. The optical modulator according to any one of claims 1 to 5, wherein two subsequent branch lines extending within the same area between the first main line and the second main line overlap in the second direction when projected in the first direction.

7. The optical modulator according to any one of claims 1 to 6, wherein two subsequent branch lines extending within the same area between the first main line and the second main line have different lengths, and the longer branch line is at least 5% longer than the shorter branch line.

8. The optical modulator according to any one of claims 1 to 7, wherein the distance between the main line on the substrate of the first electrode and the second electrode and the subsequent main line changes in the second direction and / or the first direction.

9. The distance between the main lines is - Alternately increasing towards the maximum distance and decreasing towards the minimum distance, and / or - Increasing or decreasing by a random amount within the maximum and minimum distances, and / or - A series of distances in the second direction between the main lines across the substrate change randomly, and the sum of the distances is between the minimum total distance and the maximum total distance The optical modulator according to any one of claims 1 to 8.

10. The main line and the branch line extending from the main line are formed as a series of connected sub-main lines along which the branch line extends, and the series of sub-main lines are connected to form the main line, - The branch lines extending on the same side of the sub-main line have equal lengths, and / or - The branch lines extending on the same side of the secondary main line are parallel, and / or - The number of branch lines extending from both sides of the secondary main line is equal, The optical modulator according to any one of claims 1 to 9.

11. The branch lines extending on the same side of the secondary main line and the branch lines extending from the subsequent secondary main lines of the same main line - Have different lengths, and / or - Form an angle different from the first direction, and / or - Have a different number of branch lines extending from the side of the secondary main line, The optical modulator according to claim 10.

12. The optical modulator according to claim 10 or 11, wherein the angle between the branch line and the first direction in the secondary main line is randomly selected between 45 degrees and 90 degrees.

13. The optical modulator according to any one of claims 10 to 12, wherein the secondary main line and the subsequent connected secondary main line in the same main line are shifted relative to each other in both the first direction and the second direction.

14. The pattern in which the first and second electrodes are arranged is subdivided into a set of blocks extending in the first and second directions across the substrate, and each block includes a plurality of secondary lines of a part of a plurality of main lines of the first electrode and a plurality of secondary lines of a part of a plurality of main lines of the second electrode, and at least one of the blocks is repeated multiple times on the substrate. The optical modulator according to any one of claims 1 to 13.

15. - In a part of the block, the electrode of the secondary main line includes a plurality of branch lines, and in a part of the block, the electrode does not include a plurality of branch lines, and / or - In a part of the block, the secondary main line is straight, and in a part of the block, the secondary main line is wavy, The optical modulator according to any one of claims 1 to 14.

16. The pattern in which the electrodes are arranged is subdivided into a plurality of 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 plurality of parts, generating an optical effect. The optical modulator according to any one of claims 1 to 15.

17. The optical modulator according to any one of claims 1 to 16, wherein the electrode geometry selected from the group consisting of thickness, width, shape, area, and volume is different across at least one of the first and second substrates.

18. The primary electrode is 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 semiconductor layer, and the secondary electrode is electrically connected to the primary electrode line by the semiconductor layer, whereby only the transmission current exceeding the threshold voltage on the primary electrode becomes possible, and / or - The secondary electrode is permeable, and / or - The secondary electrode includes a capacitor configured to locally hold electric charges, and / or - The secondary electrode includes a photovoltaic semiconductor material, and the secondary electrode supplies power to the primary electrode line, The optical modulator according to any one of claims 1 to 17.

19. The optical modulator according to any one of claims 1 to 18, wherein a plurality of electrodes extend two-dimensionally across a substrate, and in a third dimension, at least a first electrode among the plurality of electrodes is set apart from at least a second electrode among the plurality of electrodes, and optionally, an insulator is disposed between the first electrode and the second electrode.

20. The optical modulator according to any one of claims 1 to 19, 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 electrode and the second electrode are shifted relative to each other.

21. A substrate for use in an optical modulator, wherein a plurality of electrodes are applied to the same side of the substrate, each of the plurality of electrodes is arranged in a pattern across the substrate, and at least a first electrode and a second electrode among the plurality of electrodes each include - 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 plurality of main lines, - A plurality of branch lines extending from the main lines into the area between the main lines, and the branch lines extending into the area between the first main line and the second main line of the first electrode and the second electrode extend alternately from the first and second main lines and extend into the same area, and at least one of the two subsequent branch lines extending into the area extends at least half as measured along a second direction orthogonal to the first direction across the area, the plurality of branch lines.

22. 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 to face each other, a plurality of electrodes are applied to the inner sides of each of the first and second substrates, and the plurality of electrodes of at least one of the substrates include at least a first electrode and a second electrode, and each of the plurality of electrodes is arranged in a pattern across the substrate, and each of the plurality of electrodes - includes a plurality of main lines extending in a first direction across the substrate, the plurality of main lines of the plurality of electrodes are arranged alternately with respect to each other on the substrate, and the first electrode and the second electrode each - are a plurality of branch lines extending from the main lines into the area between the main lines, and the branch lines extending into the area between the first main line and the second main line of the first electrode and the second electrode extend alternately from the first and second main lines, and at least one of the two subsequent branch lines extending into the same area extends at least half as measured along a second direction perpendicular to the first direction across the area, the first substrate and the second substrate including a plurality of branch lines - an optical layer between the first substrate and the second substrate - including a fluid containing particles, the particles being charged or chargeable, and an optical layer including the fluid, selecting an alternating current or an alternating voltage of one of a plurality of maximum amplitudes corresponding to one of a plurality of levels of transmissivity or reflectivity in the optical modulator - applying an alternating current to the electrodes to obtain an electromagnetic field between the electrodes that causes electrophoretic movement of the particles towards or away from the electrodes, thereby generating modulation of the optical properties of the optical modulator - including an optical modulator method.

23. A temporary or non-temporary computer-readable medium including data representing instructions that, when executed by a processor system, cause the processor system to perform the method according to claim 22.

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