Optical modulator, substrate including electrode, and smart glass

Abstract

Some embodiments are directed to an optical modulator comprising a transparent or reflective substrate, a plurality of electrodes applied to the substrate in a pattern across the substrate. The controller may apply an electrical potential to the electrodes to obtain an electromagnetic field between the electrodes to provide electrophoretic motion of the particles toward or away from the electrodes.

Description

[0001] This application is a divisional application of the invention patent application with an international application date of June 20, 2022, a national application number of 202280053722.6, and a name of “Light modulator, substrate including electrodes, and smart glass”. Technical Field

[0002] The disclosed subject matter relates to light modulators, substrates, light modulator methods, and computer readable media. Background Art

[0003] Optically active glass is known in the prior art. Typically, an optically active glass system comprises two parallel plates made of a transparent dielectric material, such as glass or a plastic material. The internal volume between the plates is subdivided into a plurality of small independent volumes or individual cells filled with a dielectric liquid. The liquid contains a suspension of particles of a dielectric material, a charged or chargeable material. The faces of the two plates facing each other carry electrodes facing each other. The electrodes are connected to a power source associated with a control device.

[0004] The electrodes of each plate are formed by pairs of interlaced combs. The electrodes of the two interlaced combs can be subjected to voltages of the same or opposite polarity. By applying a suitable voltage across the electrodes, the particles can be concentrated at different locations between the electrodes, giving the system a transparent or opaque appearance.

[0005] There are a number of disadvantages associated with the known system. When the known glass is in a transparent configuration, the electrodes applied to the plate can cause diffraction effects. Diffraction effects are undesirable for glass. In certain circumstances, the presence of diffraction effects can also be detrimental to safety. For example, if the optically active glass is applied to a vehicle (such as an automobile), the presence of diffraction can confuse or distract the operator of the vehicle.

[0006] Furthermore, the drive of known systems can be improved.

[0007] Another disadvantage of the known system is that in the opaque configuration, it is desirable for the glass to have a uniform appearance. This aspect can also affect safety. For example, if the glass is configured in an intermediate state between opaque and transparent, the lack of uniformity may cause confusion or distraction. It is also desirable that the switching process occurs at a uniform speed across the entire glass.

[0008] Another disadvantage of known systems is that the presence of physical contaminants may have a negative impact on the performance of the device. For example, particles, fibers, stones, lumps, granules, etc. present in the fluid may cause physical damage to the electrodes. In addition, these contaminants may be conductive or may absorb charges from the fluid on its surface and become conductive, thereby disturbing the electric field between electrodes on the same substrate or on different substrates or causing them to short-circuit. These contaminants at various capacities will have a negative impact on the optoelectronic performance of the system. In addition, they can also interfere with the ideal current balance in the device, resulting in a shortened device life. Summary of the invention

[0009] It would be advantageous to provide an improved substrate provided with electrodes and a light modulator including such an improved substrate to address these and other issues. What the inventors have discovered is 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 concern allows for the application of substrates with less diffraction, a more uniform opacity state across the substrate, and a more uniform switching speed. Addressing the second concern allows for substrates that are less susceptible to the negative effects of physical contaminants present between the substrates.

[0010] Photoactive glass, in particular so-called smart glass, is an important application of transparent or reflective substrates using electrodes. Transparent or reflective substrates for such applications (e.g. smart glass) can have two electrodes, each of which has a plurality of main lines. The lines are arranged alternately on the substrate so that an electric field can be established between subsequent or adjacent lines by providing a potential difference to the electrodes.

[0011] Multiple branch lines can extend from these main lines. By extending the branch lines to at least half the distance between two main lines, better uniformity and / or lower diffraction effects can be obtained. In addition, when projected in a first direction, two subsequent branch lines extending to the same area between the first main line and the second main line can overlap in a second direction. These branch lines increase the number of angles found on the substrate, thereby reducing diffraction effects. For example, the angle can be selected to be different from the vertical direction and / or can be varied to further reduce diffraction. Diffraction can also be reduced by changing the distance between the main line and the subsequent main line on the substrate.

[0012] A substrate according to an embodiment can be used for a light modulator (also referred to as an optical modulator). For example, two such substrates can be arranged relative to each other so that charged particles suspended in a fluid between the substrates can be moved by applying a voltage to the electrodes. Typically, the electrode designs of the bottom substrate and the top substrate are identical, but this is not necessary. Similarly, the two electrode designs are usually aligned with each other, but this is also not necessary. The particles can absorb or reflect light. The reflection can be specular reflection or diffuse reflection, or between specular reflection and diffuse reflection. The particles can emit light, for example, with phosphorescence or fluorescence.

[0013] Light modulators provide a panel that can change transparency or reflectivity. In one embodiment, the color or color intensity can be changed, etc. Light modulators can be used as covers, such as covers for containers (e.g., closets, cabinets, etc.). Depending on the specific application, light modulators are also called ambient light modulators, dynamic light modulators, optical modulators, color modulators, IR modulators, UV modulators, IR active filters, UV active filters, or dynamic color filters.

[0014] One particularly advantageous application is in photoactive glass, which is also referred to in the art as smart glass, smart window, controllable glass, optical panel, electronic signage, dynamic light panel, dynamic color panel, active color panel, active light panel, active light surface, active color surface, dynamic light surface, or dynamic color surface.

[0015] In one embodiment, the controller is configured to apply an electric potential to electrodes on the substrate of the light modulator to obtain an electromagnetic field between the electrodes. The electromagnetic field provides electrophoretic movement of particles toward or away from the electrodes. As the position of the particles changes, the optical properties of the panel also change, for example, the transparency or reflectivity of the panel changes. If the particles are colored, the color of the panel will also change. By changing the paired electrodes between which the field is established, the particles can move in the desired direction. What the inventors have found is that the control of the light modulator is not necessarily limited to only changing the field applied between the electrodes, but can also include changing the maximum amplitude. It should be noted that the use of alternating current is beneficial. For example, by driving with a lower maximum amplitude, the rate of change of the light modulator is changed. For example, when driving to a desired target transparency or target reflectivity, this is advantageous, and the maximum amplitude can be reduced to avoid overshoot. When starting to drive to the target transparency or target reflectivity, the maximum amplitude can also be increased instead. For example, the controller can be configured to obtain one of multiple transparency levels or reflectivity levels of the light modulator by using an alternating current or alternating voltage with one of multiple maximum amplitudes. The above relationship may be represented by an algorithm or the like. The relationship between transparency level or reflectivity level and maximum amplitude may be controlled by a look-up table, for example indicating a sequence of maximum amplitudes to drive towards transparency or reflectivity. It should be noted that an alternating voltage may also be used.

[0016] In addition to changing the electrodes between which the signal is applied, changing the maximum amplitude of the drive signal can also be used to improve balanced drive. For example, the power (e.g., maximum amplitude) applied to some electrodes may be different from the power applied to other electrodes. For example, the controller can be configured to apply a potential difference between subsequent electrodes on the same substrate while applying a potential difference between opposing electrodes on opposing substrates.

[0017] In an embodiment, each substrate has at least two electrodes, but there may be more than two electrodes. For example, at least three electrodes are applied to at least one of the first substrate and the second substrate. For example, in one embodiment, the first substrate may be applied with two electrodes and the second substrate may be applied with three electrodes.

[0018] A system in which one substrate has at least two electrodes and the other substrate has at least three electrodes has a number of advantages. For example, such a light modulator can be driven so as to reduce the so-called curtain effect. The curtain effect occurs during the closing of a window, where it seems as if a curtain is drawn between the electrodes. The curtain effect is a disadvantage, which is obviously distracting in itself, and it also increases diffraction. On the side with 3 electrodes, the electrodes are closer to each other than on the side with 2 electrodes, for example less than 50 microns, more preferably less than 40 microns (e.g. 35 microns). This means that the electric field is stronger. Therefore, closing is faster and the curtain effect is reduced. For a 2+2 panel, moving the electrodes closer to each other can lead to a reduction in maximum transparency or maximum reflectivity. But this can be avoided when additional electrodes are available. When opening, some additional electrodes may not be used, so the loss of maximum transparency or maximum reflectivity is small. Additional electrodes on the substrate (e.g. more than two electrodes) can be configured not to attract particles when the panel is opened, but to attract particles when the panel is closed. For example, a panel with at least 2 electrodes per substrate can have at least 4 electrodes in total. The substrates in the panel can have at least 5 electrodes (e.g., a 2+3 design); or at least 6 electrodes (e.g., a 2+4, or 3+3 design); or at least 8 electrodes (e.g., a 4+4 design), or 3 substrates stacked in two 2+2 designs, with two electrodes on each side of the middle substrate.

[0019] The inner sides of the first substrate and the second substrate are arranged relative to each other, and a plurality of electrodes are applied to the inner side of each of the first substrate and the second substrate. In this way, each of the first substrate and the second substrate has an inner surface, wherein a portion of the inner surface of each substrate is provided with a plurality of electrodes, and a portion of the inner surface is not provided with electrodes but is in fluid contact with the particle-containing fluid. Therefore, the inner side of each of the first substrate and the second substrate has a certain inner surface area, i.e., the total surface area occupied by the electrodes and the surface area of ​​the inner surface not occupied by the electrodes. At least a portion of the inner surface area of ​​at least one of the first substrate and the second substrate is provided with a protective coating. The protective coating prevents pollutants such as particles, fibers, stones, lumps, and granules in the liquid from directly contacting the electrodes. These pollutants can be formed in various ways (such as by aggregation of smaller particles, static electricity, entrainment between electrodes, etc.). The pollutants can cause: short circuits between electrodes on opposite substrates, short circuits between adjacent electrodes on the same substrate, or physical damage to the electrodes themselves, or any combination of the above.

[0020] Thus, in one embodiment, the protective coating at least partially or completely prevents these contaminants from causing physical damage to the electrode. In one embodiment, the protective coating at least partially or completely prevents these contaminants from causing a short circuit between the electrodes. In one embodiment, the protective coating prevents both physical damage to the electrode and short circuit between the electrodes.

[0021] The protective coating has no substantial effect on the basic operation of the present technology and therefore does not require electrical or optical properties that are particularly relevant to the electrode design and device operation described herein. To prevent short circuits between electrodes, the protective coating is generally non-conductive or electrically insulating. Thus, in one embodiment, the protective coating forms an electrically insulating layer between at least a portion of the electrodes. In one embodiment, the protective coating has a resistivity of at least 10 7 Ω·m, preferably at least 10 9 Ω·m, more preferably at least 10 10 Ω·m, more preferably at least 10 11 Ω·m. As used herein, the term "electrically insulating" should be considered synonymous with "non-conductive" or "non-conductive" or "non-conductive".

[0022] Such an electrical insulating layer can also generally form a mechanical barrier near the electrode and / or for the electrode to reduce physical damage to the electrode. Therefore, in one embodiment, the protective coating forms an electrical insulating layer and a mechanical barrier between the contaminants in the optical layer and at least a portion of the electrode. However, the protective coating can also only provide protection to prevent the electrode from being mechanically damaged. Therefore, in one embodiment, the protective coating only forms a mechanical barrier. The protective coating can be arranged on at least one of the first substrate and the second substrate, or only one of the first substrate and the second substrate, or at least a portion of the inner surface of both the first substrate and the second substrate. The coating can be substantially coated or only coated on one or more areas where electrodes are provided, or can be substantially coated or only coated on one or more areas where electrodes are not provided, or a combination of the above two. Typically, at least a portion of the inner surface area of ​​at least one of the first substrate and the second substrate is applied with an electrode provided with a protective coating. However, in some embodiments, a protective coating is basically provided only for the portion of the inner surface of at least one of the substrates where electrodes are not provided.

[0023] The coating may be disposed on at least a portion of the surface area of ​​a plurality of electrodes, may be disposed on at least a portion of the electrodes on only one substrate, or may be disposed on at least a portion of the electrodes on both substrates. For example, a protective coating may be disposed on only one substrate, the protective coating covering at least a portion of the electrodes applied to the substrate, while the opposing substrate will not include a protective coating covering the electrodes or covering portions of the substrate to which the electrodes are not applied. Thus, in one embodiment, the protective coating covers at least a portion of the surface area of ​​a plurality of electrodes of one of the first substrate and the second substrate, while the opposing substrate is not provided with a protective coating.

[0024] In another embodiment, both substrates may be provided with a protective coating covering at least a portion of the inner surface of the substrates.Thus, in one embodiment, the protective coating is provided on at least a portion of the surface area of ​​the inner surface of both the first substrate and the second substrate.

[0025] The protective coating can cover a portion of the total surface area of ​​the electrode inside the substrate, can cover a portion of the total surface area of ​​the inside of the substrate that is not covered by the electrode, or can substantially cover the entire inner surface area of ​​the substrate, for example, by means of a continuous (preferably uniform) coating that substantially covers the entire inner side of the substrate and multiple electrodes applied to the inner side of the substrate. In one embodiment, the protective coating covers at least 1% of the total inner surface area of ​​the substrate, preferably at least 10%, more preferably at least 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%. In one embodiment, the protective coating covers at least 1% of the total surface area of ​​multiple electrodes on the substrate, preferably at least 10%, more preferably at least 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%. This total coating area can be distributed in the entire surface area occupied by the electrode. The protective coating can be mainly arranged or only arranged on the substrate area covered with the electrode, or mainly arranged or only arranged on the substrate area that does not cover the electrode.

[0026] The protective coating can substantially cover the entire or entire surface area of ​​at least one of the first substrate and the second substrate, so that the electrodes applied to the substrate and the inner surface of the substrate where the electrodes are not applied are provided with a protective coating. For example, the protective coating can be in the form of a continuous (preferably uniform) coating for protecting substantially all or all of the electrodes applied to the inner side of the substrate from physical damage and / or short circuit. This full protective coating can be arranged on the inner side of at least one of the first substrate and the second substrate. This full protective coating can also be arranged on the inner side of only one of the first substrate and the second substrate, while the relative substrate and the electrodes applied on the relative substrate are not provided with a protective coating. Therefore, in one embodiment, the inner side of one of the first substrate and the second substrate is completely provided with a protective coating, so that the entire surface of the multiple electrodes applied to the inner side and the inner side of the substrate where the electrodes are not provided are substantially covered with a protective coating, while the relative substrate is not provided with a protective coating. This full protective coating can also be arranged on the inner side of both the first substrate and the second substrate. Therefore, in one embodiment, the inner side of the first substrate and the second substrate, i.e. the entire inner surface area, is completely provided with a protective coating, so that the entire surface of the multiple electrodes applied to the inner side and the inner side of the substrate where no electrodes are provided are basically covered with the protective coating.

[0027] The thickness of the protective coating can vary widely. Typically, the thickness of the protective coating is in the range of 1 nm to 100 μm, preferably in the range of 10 nm to 50 μm, preferably in the range of 100 nm to 10 μm. A reasonable lower limit for the thickness of the protective coating depends primarily on the degree of electrical insulation required, which in turn depends on the potential difference applied to the electrodes and the expected conductivity of the contaminants. A suitable upper limit for the thickness of the protective coating depends primarily on the minimum distance between the electrodes on the relative substrates, which is typically less than 500 microns, preferably less than 200 μm, preferably less than 100 μm, and more preferably less than 50 μm, such as less than 30 microns.

[0028] The selection of suitable protective coating thickness also depends on the degree of coverage of the first substrate and / or the second substrate. More specifically, whether a continuous (preferably uniform) protective coating is applied or an intermittent, discontinuous coating as described below is applied, this helps determine the minimum thickness required to achieve the desired effect of preventing electrode short circuits and / or preventing physical damage.

[0029] The protective coating may be applied in a discontinuous form, wherein the entire surface of the electrode and the entire surface within the substrate are not coated with the protective coating. Such discontinuous forms of the coating may have a random pattern or may form a regular pattern, which may be selected based on a certain predetermined effect requirement of the optoelectronic performance of the device.

[0030] In one embodiment, the protective coating is provided as a pattern coating. Such a pattern coating can be applied to the side of the substrate bearing the electrode using masks known in the art.

[0031] The pattern may be coated in such a way that some electrodes are provided with a protective coating, while other electrodes are not provided with a protective coating and are in fluid contact with the fluid. In one embodiment, a first main line on a first substrate is provided with a protective coating, while a second main line on a second substrate opposite to the first main line is not coated and the second main line is in fluid contact with the fluid, or vice versa. The pattern may be a regular pattern, with the electrode surfaces covered with a protective coating in an alternating manner. In one embodiment, a plurality of main lines on a first substrate and a second substrate are alternately provided with and without a protective coating.

[0032] The pattern is not limited to a one-dimensional pattern. For example, the protective layer can be in a grid or mesh shape, optionally in a random mesh or random mesh shape. Such mesh or mesh protective coatings of the two substrates can be similar and / or aligned in direction and position, but this is not required.

[0033] The patterns described above can be combined in the same substrate and on an opposing substrate. For example, the inner side of the first substrate can be provided with a full protective coating that substantially covers all electrodes and the inner side of the substrate where no electrodes are provided, while the opposing substrate may not be provided with a coating. In one embodiment, a patterned coating is provided on at least a portion of the inner side of one of the first and second substrates (thus covering a portion of the electrodes, and optionally covering a portion of the substrate where no electrodes are provided), but is not provided on the opposing substrate. In one embodiment, the coating is provided on the inner side of at least one of the first and second substrates in a random pattern, so that at least a portion of the plurality of electrodes applied to the inner side and / or at least a portion of the inner side of the substrate where no electrodes are provided is provided with a coating, and at least a portion of the plurality of electrodes applied to the inner side and at least a portion of the inner side of the substrate where no electrodes are provided is not provided with a coating.

[0034] The protective coatings on the substrates do not need to be aligned with each other. However, a discontinuous protective coating, such as a grid, can be applied to the two substrates, the main lines of which are at an angle to each other, such as 15, 30 or 45 degrees. In another embodiment, the protective coating is applied to the two substrates in the form of parallel lines, wherein the parallel lines on one of the two substrates are rotated 90 degrees relative to the parallel lines on the opposing substrate. In this way, by combining the line patterns on the opposing substrates, a protective coating with a mesh-type pattern can be produced.

[0035] In an exemplary embodiment, when at least one of the substrates is completely provided with a protective coating, that is, when the entire surface of the plurality of electrodes and the inner side of the substrate where no electrodes are provided are substantially covered with a (preferably substantially uniform) protective coating, a protective coating having a thickness of less than 10 nm is used. In an exemplary embodiment, a protective coating having a thickness of 1 micron or more is suitable for being applied as a discontinuous layer to at least a portion of only the electrodes, or only at least a portion of the inner surface of the substrate where no electrodes are provided, or a combination of the two, regardless of whether the protective coating is applied in a specific pattern. In an exemplary embodiment, a protective coating having a moderate thickness (i.e., a thickness in the range of 10 nm to 1 micron) can be applied as either a complete, continuous coating or a discontinuous coating.

[0036] As described above, the protective coating can be uniformly disposed over the inner surface area of ​​the substrate or can be patterned in specific areas. In other words, the protective coating need not be completely continuous, and internal gaps, pinholes, holes, etc. can be tolerated as long as their size and distribution are significantly smaller than the size and distribution of larger physical contaminants. Therefore, such gaps can be allowed to exist in the protective coating as long as the maximum size of the gap does not exceed the minimum distance between two electrodes on the substrate for the coating to have the desired protective effect.

[0037] Likewise, the size of the contaminants that can be tolerated depends on the electrode design or pattern, and also on the distance between electrodes on the same substrate and the distance between electrodes on opposing substrates. Therefore, the quality and continuity of the protective coating are defined by the need to statistically limit or eliminate the impact of these contaminants on the appearance and performance of the device. For example, it is practicable that the protective coating allows gaps in the protective coating to extend to a maximum of 90% of the minimum distance between independent electrodes on the same substrate or on opposing substrates (i.e., the minimum distance between electrodes on the same substrate and the cell gap of the device).

[0038] The protective coating can be made of various materials and material combinations. Those skilled in the art can select suitable materials that meet the above-mentioned physical damage protection requirements and short circuit protection requirements, and can also select coating thickness, coating uniformity, methods for driving equipment, etc. For example, suitable materials are inorganic materials and inorganic compositions, such as silicon nitride, silicon dioxide, silicon oxynitride, polycrystalline silicon, amorphous silicon, aluminum oxide, tantalum pentoxide, and zirconium oxide and the above-mentioned combinations thereof, and suitable materials can also be organic materials or polymer materials, including but not limited to: polyimide, fluorine-containing polymer, silicone resin, polytetrafluoroethylene, polyimide resin, photoresist, epoxy resin, and benzocyclobutene-based polymers and the above-mentioned combinations thereof. These inorganic materials and inorganic compositions can also be combined with organic materials and / or polymer materials. The protective coating material is rigid or non-rigid. In an exemplary embodiment, the protective coating material is non-rigid.

[0039] Depending on the selected application and coating thickness, the protective coating can be transparent, translucent or reflective, have a specific color or have a wide wavelength range. In some embodiments, the protective coating is a transparent coating or a translucent coating. In some embodiments, the protective coating is a reflective coating. It is also possible to combine transparent portions, translucent portions and / or reflective portions of the coating on the same substrate or on relative substrates. In some embodiments, the protective coating provides an additional optical function for the device. In some embodiments, the additional optical function is an independent optical function. In some embodiments, the additional optical function is an optical function that matches the optoelectronic effect of the device. For example, the optoelectronic effect can be a reflection, anti-reflection, scattering and / or anti-diffraction effect for all wavelengths of light, or a reflection, anti-reflection, scattering and / or anti-diffraction effect for part of the electromagnetic spectrum (such as: UV, visible light, and / or IR).

[0040] In order to produce significant light refraction, the protective coating material can be selected to have a sufficiently different refractive index compared to the refractive index of the fluid solvent. For example, a protective coating made of silicon nitride with an optical refractive index of 3 can be combined with a fluid solvent with an optical refractive index of less than 2. This refractive index difference will cause the incident light to refract, and the change in light direction follows Snell's law. The light modulator can then direct the incident light in a specific designed direction. This effect can be combined with the specific shape and morphology of the patterned protective coating to refract the light in multiple directions, thereby increasing light scattering or light haze. Similarly, different protective coatings from the same substrate or from different substrates can also be used to enhance specific light paths or light scattering.

[0041] The difference in refractive index between the substrate and the particle-containing fluid can produce light reflection. Using a protective coating (with or without pattern) made of a material with an intermediate optical refractive index limits back reflection, thereby producing an anti-reflection coating. Similarly, combining various protective coatings on one substrate or all substrates can minimize back reflection of incident light or enhance internal reflection. Here, light should be considered as full spectrum light, or partial spectrum light (such as ultraviolet light, visible light or infrared spectrum light or a combination of the above).

[0042] The protective coating material can also absorb light in the visible range, such as absorbing all visible light and appearing black. The shape and position of the protective coating on one or more substrates can cause diffraction of light. Adding such a protective coating can enhance the diffraction pattern caused by the substrate design or device design, or conversely, add new diffraction directions to the light to create a scattering effect and increase blur. A black protective coating is used as an example here, but other types of light absorbing layers dedicated to specific diffraction systems can also be applied, including but not limited to absorbing light in the ultraviolet wavelength range or the infrared wavelength range. In addition, adding a protective coating with a specific pattern, shape, and optical properties to one or more substrates can offset the diffraction of light originally caused by the substrate or device to refocus the incident light to its original direction. Integrating such a coating in a device will enhance the ability to restore light diffraction, thereby exhibiting an anti-diffraction effect.

[0043] Depending on the material or material combination selected, the protective coating can be applied using various techniques known in the art, such as: sputtering, molecular beam epitaxy, pulsed laser deposition, electron beam evaporation, chemical vapor deposition, atomic layer deposition, spin coating, flexible printing coating, dip coating, spraying, inkjet printing, slit coating, and combinations of the above.

[0044] A reflow process step can be used to apply the protective coating so that the protective coating is more evenly formed on the electrode and the remaining inner surface of the substrate not covered with the electrode. For example, after depositing the coating and optionally patterning the coating, a reflow process can be added to homogenize the protective coating and improve the consistency of the substrate morphology. Typically, the reflow process is a thermal process that can be performed in various ways, including: oven heating, hot plate, infrared irradiation, laser irradiation, microwave irradiation, infrared conveyor belts, and combinations of the above. In the case where the protective coating is made of an organic material or the protective coating contains an organic material, a chemical reflow process can be performed, for example, by swelling the coating with solvent vapor or by soaking it in a liquid.

[0045] In one embodiment, the protective coating is a single layer. In one embodiment, the protective coating is a multilayer protective coating. In some embodiments, the multilayer protective coating may include alternating layers of different material compositions. For example, a protective coating comprising a polymer layer deposited on an inorganic layer may be combined. A single substrate may also include multiple protective coatings of different materials, different compositions, and different sizes.

[0046] The material used for the protective coating may differ between substrates, and a plurality of protective coatings made of different materials may be provided on the same substrate.

[0047] Another aspect of the invention is a building comprising a light modulator according to an embodiment. Another aspect of the invention is a car comprising a light modulator according to an embodiment. For example, the car and / or the building may include a light modulator and a controller configured to control the transparency or reflectivity of the light modulator by controlling the voltage on the electrodes of the light modulator, the controller being electrically connected to the light modulator or capable of being electrically connected to the light modulator.

[0048] Smart glass is an electronic device that can be driven by a power source, such as under the control of a controller. For example, the controller can instruct the power source to apply specific waveforms to specific electrodes to achieve various transparency or reflectivity effects or to erase the above effects.

[0049] An embodiment of the method may be implemented on a computer as a computer-implemented method, or may be implemented in dedicated hardware, or a combination of the two. The executable code of an embodiment of the method may be stored on a computer program product. Examples of computer program products include: a memory device, an optical storage device, an integrated circuit, a server, online software, etc. Preferably, the computer program product includes a non-transitory program code stored on a computer-readable medium for implementing an embodiment of the method when the program product is executed on a computer.

[0050] In one embodiment, the computer program comprises computer program code, which is suitable for performing all or part of the steps of an embodiment of the method when the computer program is run on a computer. Preferably, the computer program is implemented on a computer readable medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Some embodiments are directed to a light modulator comprising: a transparent or reflective substrate, a plurality of electrodes applied to the substrate in a pattern across the substrate. A controller can apply an electric potential to the electrodes to obtain an electromagnetic field between the electrodes, thereby providing electrophoretic motion of particles toward or away from the electrodes.

[0052] Further details, aspects, and embodiments will be described below, by way of example only, with reference to the accompanying drawings. The elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. In the drawings, elements corresponding to elements already described may have the same reference numerals. In the drawings:

[0053] Figure 1a An example of an embodiment of a substrate is schematically shown,

[0054] Figure 1b An example of an embodiment of a substrate is schematically shown,

[0055] Figure 1c An example of an embodiment of a branch line is schematically shown,

[0056] Figure 1d schematically shows an example of an embodiment in which the first electrode and the second electrode are arranged in a manner spanning the substrate,

[0057] Figure 2a An example of an embodiment of a substrate is schematically shown,

[0058] Figure 2b An example of an embodiment of a substrate is schematically shown,

[0059] Figure 2c An example of an embodiment of a substrate is schematically shown,

[0060] Figure 3 An example of an embodiment of a substrate is schematically shown,

[0061] Figure 4a An example of an embodiment of a substrate is schematically shown,

[0062] Figure 4b An example of an embodiment of a substrate is schematically shown,

[0063] Figure 4c An example of an embodiment of a substrate is schematically shown,

[0064] Figure 5a Several examples of embodiments of the substrate are schematically shown,

[0065] Figure 5b Schematically showing an example of an embodiment of a substrate arranged with two electrodes or arranged with three electrodes,

[0066] Figure 6a and Figure 6b A comparative example of a substrate is schematically shown,

[0067] Figure 6c and Figure 6d An example of an embodiment of a substrate is schematically shown,

[0068] Figure 7a schematically illustrates an example of an embodiment of a light modulator,

[0069] Figure 7b schematically illustrates an example of an embodiment of a light modulator,

[0070] Figure 7c An example of an embodiment of a motor vehicle is schematically shown,

[0071] Figures 8a to 8c schematically shows an embodiment of a light modulator,

[0072] Figure 9a schematically illustrates an example of an embodiment of a logo and a grid,

[0073] Figure 9b An example of an embodiment of a substrate is schematically shown,

[0074] Figure 9c to Figure 9d An example of an embodiment of a substrate is schematically shown,

[0075] Fig.10 schematically illustrates an example of an embodiment of a light modulator method for controlling a light modulator,

[0076] Fig.11a schematically shows a computer-readable medium, the writable portion of which comprises a computer program according to one embodiment,

[0077] Fig.11b schematically shows a representation of a processor system according to one embodiment,

[0078] Figures 12 to 37 schematically illustrates an example of an embodiment of a light modulator,

[0079] Fig.38 Schematically illustrates an example of a physical contaminant that causes an electrical short between electrodes on opposing substrates in a prior art optical modulator,

[0080] Fig.39 Schematically illustrates an example of a physical contaminant that causes an electrical short between adjacent electrodes on a single substrate in a prior art optical modulator,

[0081] Figures 40 to 45 schematically illustrates an example of an embodiment of a light modulator,

[0082] Figure 46 to Figure 48 An example of an embodiment of a substrate for use in a light modulator is schematically shown.

[0083] Reference numerals list

[0084] The list of symbols and abbreviations described below are provided to facilitate understanding of the drawings and they should not be construed as limiting the claims.

[0085] 10. Optical Modulator

[0086] 11. First substrate

[0087] 12. Second substrate

[0088] 13, 13a, 13b electrodes

[0089] 14, 14a, 14b electrodes

[0090] 15 Fluid

[0091] 16 Controller

[0092] 30 pcs

[0093] 20 Car

[0094] 21. Optical Modulator

[0095] 40 Optical Modulator

[0096] 41 First substrate

[0097] 42 Second substrate

[0098] 43 Third substrate

[0099] 46 Controller

[0100] 100 substrates

[0101] 101 First Direction

[0102] 102 Second Direction

[0103] 110 first electrode

[0104] 120 second electrode

[0105] 111-113 Main Line

[0106] 121-123 Main Line

[0107] 131-134 branch line

[0108] 141-144 branch line

[0109] 150 Area

[0110] 151 Half the distance between two subsequent main lines

[0111] 152 Distance between two subsequent branch lines

[0112] 153 Distance between two subsequent main lines

[0113] 161 protrusion

[0114] 162 Virtual Line

[0115] 171-174 base plate

[0116] 200 substrates

[0117] 201-206 Main Line

[0118] 251-253 Distance between subsequent main lines

[0119] 221 Part 1

[0120] 222 Connection part

[0121] 223 Part 2

[0122] 231 Line Clearance

[0123] 232 Distance

[0124] 300 substrates

[0125] 301 Main Line

[0126] 310,320 sub-main lines

[0127] 311 Connection

[0128] 321,322 sub-main lines

[0129] 400 substrate

[0130] 410, 420 main lines

[0131] 411, 412 branch lines

[0132] 421, 422 branch lines

[0133] 450 substrate

[0134] Blocks 451-454 DETAILED DESCRIPTION

[0135] Although the presently disclosed subject matter may be implemented in many different forms, one or more specific embodiments thereof will now be shown in the drawings and described in detail herein, it being understood that the contents of this disclosure should be considered as examples of the principles of the presently disclosed subject matter and are not intended to limit the subject matter to the specific embodiments shown and described.

[0136] Hereinafter, for ease of understanding, the elements of the embodiments are described in operation. However, it is apparent that the various elements are arranged to perform the functions described by them. In addition, the subject matter disclosed herein is not limited to the embodiments, but also includes the combination of each other feature described herein or described in the mutually different dependent claims.

[0137] Figure 1a An example of an embodiment of a substrate 100 is schematically shown. At least two electrodes are arranged in a manner across the surface of the substrate 100. Figure 1a Two electrodes are shown on the same surface: a first electrode 110 and a second electrode 120. For example, more than two electrodes can be provided on the same side of the substrate to facilitate finer control. For example, multiple electrodes can be used to facilitate a segmented substrate, for example, for a segmented light modulator. For example, in a segmented light modulator, certain areas may have different optical properties, such as different transparencies or reflectivities. An embodiment with two electrodes is shown below, but additional electrodes can also be added thereto, for example by replicating similar structures adjacent to each other.

[0138] The first electrode 110 and the second electrode 120 are applied on the same side of the substrate. The two electrodes are arranged in a manner across the substrate. For example, in order to facilitate stacking three or more substrates, there may also be one, two or more electrodes on the other surface of the substrate 100. The electrodes may be applied to the substrate by lithography (e.g., using a mask representing an electrode pattern). The electrodes may also be applied by embedding the electrodes in the substrate.

[0139] The first electrode 110 and the second electrode 120 each include a plurality of main lines. Figure 1aAs shown, 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 will include more than three lines. The main lines extend across the substrate. The multiple main lines of the first electrode and the second electrode are arranged alternately on the substrate. The main lines extend across the substrate in a first direction 101. When viewed from a second direction 102, the main lines from different multiplex systems meet alternately, for example, the main lines of the first multiplex system and the second multiplex system from the first electrode and the second electrode, respectively, meet alternately. The first direction and the second direction are angled with each other, and the angles are generally perpendicular. The first direction and the second direction can each be parallel to the side of the substrate, but this is not necessary.

[0140] One exciting application of a substrate such as substrate 100 is in smart glass (e.g., light modulators), which can be applied to home homes, offices, greenhouses, cars, etc. The transparency level or reflectivity level of the smart glass can be adjusted electronically. For example, in the smart glass, two substrates such as substrate 100 are stacked so that the sides with two electrodes applied face each other. A fluid with particles is enclosed between the two substrates. Embodiments of the smart glass will be discussed further below. In one embodiment, an electrode (e.g., two or more electrodes) is applied to one surface of each substrate. In order to facilitate, for example, stacking three or more substrates, one, two or more electrodes may also be applied to another surface of substrate 100.

[0141] Some embodiments below show examples of modulating transparency levels or reflectivity levels. Light modulators can be adjusted for other optical effects. For example, if desired, the embodiment can be changed to different translucency levels instead of different transparency levels. If desired, the type of particles used in one embodiment can be changed, for example, particles that absorb or reflect different wavelengths and reflect different diffuse specular degrees. For example, in one embodiment, light modulators can modulate different reflective levels. Particles can also emit light. Stacking multiple optical layers further increases the possibilities.

[0142] Two alternating sets of main lines are sufficient to provide an electrically adaptable glass; thanks to the alternation of the two sets, the electric field in any portion of the substrate can be controlled since two opposing electrodes surround the portion from two opposing sides.

[0143] Figure 1b An example of one embodiment of a substrate 100 is schematically shown. Figure 1bTwo main lines of substrate 100 are shown. Shown are main line 121 and main line 112. These main lines may pass through a major portion of the substrate, for example, substantially throughout the entire substrate.

[0144] By adjusting the shape of the electrodes, the undesirable diffraction effects can be modified. Reducing the diffraction effects is particularly important for transparent substrates, as the diffraction effects will not be noticed for example for reflective displays (such as those that can be used in e-readers). The inventors have found that by orienting the line shape of the electrodes at a plurality of different angles, diffraction is spread out in space, thereby reducing the intensity of the strongest diffraction point, and optical diffraction will be reduced.

[0145] like Figure 1b As shown, a plurality of branch lines are connected to the main line and extend from the main line. Figure 1b 1 and 2 show branch lines 131 to 134 included in the electrode 121, and branch lines 141 to 144 included in the electrode 112. The branch lines are attached to the main lines and extend to the area between the main lines. Figure 1b Such an area is shown: the area 150 between the electrode 121 and the electrode 112. The branch lines 131 and 132 of the electrode 121 and the branch lines 141 and 142 of the electrode 112 extend into the area 150 between the electrode 121 and the electrode 112. Similar to the main line, the branch lines also alternate. In particular, for example, when viewed from a first direction, the branch lines extending from two different electrodes to the same area alternate. In this embodiment, the branch lines 142, 132, 141 and 131 belong to the electrodes 112 and 121 alternately. Therefore, in one embodiment, the main lines alternate when viewed from the second direction, and the branch lines alternate when viewed from the first direction. The branch lines are included in the first electrode or in the second electrode. Typically, the first electrode and the second electrode including the corresponding main line and the branch lines are not directly electrically connected, so that an electric field can be established between the first electrode and the second electrode, including establishing an electric field between their main lines and branch lines.

[0146] For example, if a virtual line is drawn in the overlap region parallel to two subsequent main lines, the virtual line will alternately intersect the branch lines of the first main line and the branch lines of the second main line.

[0147] Extending branch lines from a main line has several advantages. Even for a straight main line, the branch lines will affect the diffraction of the substrate. On the other hand, the branch lines increase the risk of disturbing the uniformity of the electric field. In particular, hot spots may be generated at locations where the ends of the branch lines are close, and weak spots may be generated at other locations. In one embodiment, at least one of two subsequent branch lines extending into the same area extends across half of the area. As a result, the non-transparent state can be more uniform and the transition between states can be faster and / or more uniform.

[0148] If the branch lines are perpendicular to the main lines, and the point at which the branch lines originate on one main line (seen in the second direction) is exactly opposite to the point at which they originate on the adjacent main line, then these branch lines cannot overlap. In this case, the branch lines emanating from one main line are collinear with the branch lines of the opposite main line, for example, so that extending one branch line causes it to overlap with the branch lines of the opposite main line. In this case, there is a risk of creating hot spots where the ends of the branch lines are close together and weak spots at other locations. This can be avoided by, for example, having a suitable angle and thus a suitable overlap. For example, the angle can depend on, for example, the line width and the line gap.

[0149] In order to avoid hot spots, such as collinear branch lines, in one embodiment, perpendicular branch lines can be avoided, for example, by staggering the branch lines. For example, the branch line origin points on the main line can be offset or staggered from each other. The angle can be selected so that one branch line does not intersect with another branch line. The staggering can be used to avoid branch lines being collinear. In one embodiment, the branch line is perpendicular to its main line and staggered with the branch line of the subsequent main line. In one embodiment, the branch lines are vertical and may or may not be staggered. In one embodiment, for example, the branch line angle can be selected from a range, such as from about 5 degrees to about 85 degrees. For very large line gaps, the angle may be closer to vertical.

[0150] exist Figure 1b In FIG. 1 , a dotted line is shown at a midpoint between electrode 121 and electrode 112. The distance 151 between electrode 121 and the midpoint line is half the distance between the two subsequent main lines 153. The dotted line is virtual and is not actually visible in one embodiment. Figure 1b 1 and 132 cover the virtual line, i.e., they extend at least across half of the region 150. For example, the branch line 131 or 132 can be projected to the virtual line 162 in the second direction 102. The length of the projected branch lines 131 and 132 is greater than half of the distance between the electrode 121 and the electrode 112. The branch lines on the opposite main lines may exceed or may not exceed half of the distance between the main lines; Figure 1bAs shown, although the branch lines 141 and 142 are not extended, the branch lines 141 and 142 may be extended so as to pass through the dotted center line.

[0151] In one embodiment, the angle between the branch line and its electrode is significantly different from normal, such as at least 5 degrees (out of 180 degrees) different from normal, such as at least 5% different from a right angle, etc. Having different values ​​can reduce diffraction effects.

[0152] In one embodiment, when projected in the first direction, two subsequent branch lines extending to the same area between the first main line and the second main line overlap in the second direction. Figure 1b Two subsequent branch lines are shown: branch line 141 and branch line 131. The area where these two branch lines overlap is shown in Figure 1b The dashed ellipse in is indicated. When the two subsequent branch lines are projected in the first direction onto a virtual line 162 extending in the second direction, the branch line 131 and the branch line 141 overlap on the projection 161 . Figure 5a An embodiment with less overlap and an embodiment with greater overlap are shown.

[0153] For example, successful simulations were performed for embodiments having branch lines penetrating into the zones with the following penetration amounts: 60-50; 63-46; 64-45; 60-46; 65-61; 83-78; 95-95. Figure 1b 1 shows a branch line with a penetration of 80-40 and an overlap of 20, the penetration and overlap being expressed as a percentage of the line gap. The numbers refer to the percentage of the branch line penetrating the line gap. Here, the length of the branch line is measured only in the second direction, for example, after projection in the first direction. In some embodiments, the overlap length in the second direction can be, for example: 10; 9; 9; 6; 26; 61, 95, etc. The overlap length is expressed as a percentage of the line gap.

[0154] In one embodiment, the distance from the end of one branch line (e.g., branch line 131) to the subsequent main line (e.g., main line 112) is approximately equal to the distance between the branch line and the subsequent branch line, such as the distance between branch line 131 and branch line 141. For example, the larger of the two distances can be less than 110% of the smaller of the distances.

[0155] In one embodiment, two subsequent branch lines from the same main line, if extending to the same area between the first main line and the second main line, have a distance between them, measured in the first direction, that is much smaller than the line gap. For example, the distance of the branch lines may be only 5% of the line gap, or less. Other embodiments have greater distances, for example, 30% of the line gap, or more. For example, branch line 131 and branch line 132 extend to the same area between main line 121 and main line 112.

[0156] Generally speaking, the beneficial effects of applying branch lines are increased if, for example, the branch lines are applied throughout the design. For example, it is not necessary to apply branch lines to all parts of the substrate, but doing so can enable the positive effects of the branch lines to be reflected in all parts. Although there may be various reasons not to use branch lines in certain parts, for example, an optical difference may be desired in order to visually distinguish a certain part, or a certain part uses a different method (e.g., waves) to avoid diffraction.

[0157] Figure 1c An example of an implementation of a branch line in a substrate is schematically shown. Figure 1c Drawn to scale. In substrate 171, an embodiment is shown where two subsequent branch lines do not overlap; as shown, there is a -5% gap. In substrate 172, an embodiment is shown where two subsequent branch lines do not overlap, but reach the same point in the area between the two main lines; as shown, there is a 0% gap. In substrate 173, an embodiment of an embodiment is shown where two subsequent branch lines have a 5% overlap. In substrate 174, an embodiment of an embodiment is shown where two subsequent branch lines have a 20% overlap. Substrate 174 shows that branch lines extending from either side to the same area can extend to more than half of the line gap. Overlapping branch lines reduces the tendency for hot spots.

[0158] Two subsequent branch lines of different main lines may have the same length or different lengths, which compensate for the overlapping area of ​​the two branch lines.

[0159] For example, in one 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, for example, the branch line can be 1.05 times the length of the shorter branch line measured along, for example, the branch line. In one embodiment, the longer branch line can be 4% to 40% longer than the shorter branch line.

[0160] For example, in one embodiment, two subsequent branch lines of different main lines have the same length.

[0161] In one embodiment, the electrode includes a plurality of straight main lines from which branch lines extend. The main lines, also referred to as center lines, can be parallel to each other. The distance between two branch lines is referred to as the branch line gap (e.g., distance 152). The distance between two main lines is the line gap. The pitch can be a line gap plus a line width, which is the physical width that can be repeated.

[0162] For example, the distance between the points where the branch lines originate on the main line can be called the branch line gap. The branch line gap can be constant for branch lines extending into the same area. The branch line gap can vary, even along the main line. The branch lines can be alternated or staggered, for example, they can be staggered with half the branch line gap in the middle. The advantage of the branch lines is that they make the distance between the electrodes uniform, so that the electric field can be established between the electrodes. At the same time, the branch lines allow to reduce diffraction effects, for example by disturbing the repeatability of the design.

[0163] In one embodiment, the electrode lines have a width selected from the range of about 1 micron to 50 microns. The line gap can be selected from the range of about 50 microns to 100,000 microns. For example, the line gap can be 800 microns (i.e., in the range of 50 to 1000 microns), although larger line gaps are also possible. Having branch lines allows for larger line gaps while maintaining a uniform electric field. Increasing the line gap reduces diffraction effects associated with the main line. In one embodiment, the line gap is at least 500 microns.

[0164] In one embodiment, the lengths of the branch lines can vary. For example, the lengths of the branch lines can alternate along the main line, or follow a repeating sequence of branch line lengths, etc. This has the advantage that the points of maximum electric field can be staggered. This is particularly advantageous for large line gaps, such as line gaps exceeding 500 microns. For example, in one embodiment, the lengths of subsequent branch lines can differ by as much as 60%.

[0165] In one embodiment, the plurality of main lines of the first electrode and the second electrode are arranged alternately relative to each other on the substrate. One of the methods for achieving the alternating arrangement is to shape the first electrode and the second electrode into a comb shape, wherein the fingers of the comb are the main lines. The staggered pattern is obtained by interlacing the fingers of the two combs. The shape of using two combs is optional. For example, Figure 1d An example of an embodiment of a first electrode and a second electrode is schematically shown, wherein the first electrode and the second electrode are arranged in a pattern spanning a substrate. For simplicity, Figure 1a and Figure 1dOnly the main line is shown without the branch line. The pattern formed is such that there is no direct electrical contact between the two electrodes. A minimum distance between the two electrodes can be guaranteed.

[0166] The design of the branch lines helps to reduce diffraction because it increases the number of angles on the substrate. In addition, many parameters can be changed to enhance this effect. For example, the length of the branch lines, the angle of the branch lines, the distance between the branch lines along the main line, the line gap, etc. Preferably, the branch lines in the same area are at least partially parallel, so that the angle of the branch line on the right side of one main line is the same as the angle of the branch line on the left side of the next main line. If the line gap changes, the branch line distance can also change, for example, the branch line distance changes proportionally according to the line gap; for example, a maximum electrode distance can be maintained between, for example, two subsequent branch lines to ensure a minimum strength of the electric field.

[0167] Figure 2a An example of an embodiment of a substrate 200 is schematically shown. Figure 2a Four main lines are shown: main line 201 to main line 204. For example, main line 201 and main line 203 can be included in a first electrode (e.g., electrode 110), and main line 202 and main line 204 can be included in a second electrode (e.g., electrode 120). Line gap 251 (e.g., the distance between main line 201 and main line 202) is shown. Line gap 252 between main line 202 and main line 203, and line gap 254 between main line 203 and main line 204 are also shown. In this embodiment, the line gap varies in the second direction. For example, line gap 251 is different from line gap 252, and line gap 252 is different from line gap 253. The variation in line gap helps to reduce diffraction effects.

[0168] Figure 2b An example of an embodiment of a substrate is schematically shown. Main lines 201 to 206 are shown. The main lines have different portions in which the line gaps may vary differently. For example, portions or regions of the main lines may extend across the substrate in the second direction. Figure 2b Two parts are shown: part 221 and part 223. Figure 2bAs depicted in [description of the figure], in part 221, the line gaps are in the ratio of 11:9:7:9:11, but in part 223, the line gaps are in the ratio of 7:11:9:9:11. Thus, in this embodiment, the line gaps between two subsequent main lines vary in the first direction and also in the second direction. There is a connecting part 222 between the first part 221 and the second part 223, and in the connecting part 222, the main lines of the two parts are connected. The line gaps in part 221 are selected according to a pattern of alternately increasing and decreasing the line gaps. The line gaps in part 223 are randomly selected.

[0169] For example, in one embodiment, the line gaps alternate between increasing to a maximum distance and decreasing to a minimum distance. For example, the line gaps can be increased by a predetermined amount or a random amount until the maximum distance is reached, and then the line gaps are decreased in a similar manner until, for example, the minimum line gap is reached. Various strategies are given below to ensure an overall change in the line gaps.

[0170] For example, in one embodiment, the line gaps are increased by 3% until the maximum value is reached, for example, at most 20% more than the initial value. For example, if x i is the line gap and x0 is the initial line gap, then x i+1 can be made equal to x i * 1.03 until x i > 1.2 * x0. After this point, the line gaps can be decreased in the same pattern or by the same percentage, or the value can be reset and then the pattern starts again, etc.

[0171] For example, in one embodiment, the line gaps are alternately increased and decreased by a percentage of the previous value (e.g., 7%). If the spacing is below the initial value minus a certain value (e.g., 10 microns), the spacing can be reset. For example, one can alternate between the rule x i+1 = 1.07 * x i and the rule x i+1 = 0.93 * x i until the point where x i < x0 - 10 is reached. After this point, the line gaps can be decreased in the same pattern or by the same percentage. The above values can be modified.

[0172] Yet another option is to alternately increase and decrease, where the amount of increase and decrease depends on the difference from the initial value. For example, it can be set as x i+1 = α(x i - x0). Again here, if the line gap exceeds the maximum value or is less than the minimum value, the line gap can be reset. α values greater than or less than 1 can be used alternately; for example, one can use x i+1 = αi (x i -x0), where the even-numbered term i makes α i >1, when the odd item i makes α i <1.

[0173] However, another option is to use alternately high line gap values ​​and low line gap values. For example, the high value can be randomly selected from a high range, and the low value can be selected from a low range. The high range and the low range can be different, or can also partially overlap.

[0174] The line spacing may vary randomly. For example, a completely random variation, or a random variation with additional criteria (e.g., alternating between high and low line spacing). For example, odd-numbered line spacings may be drawn from one probability distribution, while even-numbered line spacings may be drawn from a different probability distribution. The two distributions may have different high and low expected values, for example, the high expected value may be at least 10% or at least 20% higher than the low expected value, etc.

[0175] When the line gaps are randomly selected or modified, additional criteria must still be met. As mentioned above, the maximum line gap and the minimum line gap must be guaranteed. Another advantageous criterion to be guaranteed is that the sum of the line gaps is between the minimum total distance and the maximum total distance. This has the advantage that the connection portion 222 is still controlled. This can be achieved by drawing from a joint distribution conditioned on the desired criteria. This can also be achieved by, for example, first randomly selecting and then modifying the random selection until the constraints are met.

[0176] For example, in one embodiment, the line gap x may be selected to be i , where min x ≤x i ≤max x , and min S ≤∑x i ≤max S , where min x 、max x 、min S 、max s is the sum of the line gap limit and the line gap. The line gap may vary according to a predetermined pattern (eg, as described above) or may vary randomly (eg, drawn from one or more distributions).

[0177] The line gap may vary in the first direction or in the second direction. In this case, the variation may be controlled so as to control the shape of the connecting portion. For example, Figure 2c An example of an embodiment of a substrate is schematically shown. Two main lines 201 and 202 are shown. Figure 2cAt the top of the circuit, there is a line gap 231. Figure 2c , the line gap is changed. Main line 201 is a dotted line, showing how the main line would continue if there was no shift. Distance 232 is the distance between the dotted main line 201 and the main line 202 after the bottom of the figure is shifted. By keeping the percentage increase or decrease of distance 232 compared to line gap 231 below a threshold, the connection portion can be controlled, for example so that the change is not too steep. For example, in one embodiment, distance 232 is less than 1.35 times line gap 231. The change in line gap can also be controlled. Instead of controlling the size of the line gap, or in addition to controlling the size of the line gap, the connection portion in the main line, such as the angle formed by the connection portion of line 201 and line 202, can also be controlled, and the angle should, for example, be below a threshold to avoid the line becoming too steep. Another way of controlling is to verify that subsequent connection portions do not become too close to each other.

[0178] Simulations have confirmed that varying line spacing is beneficial for reducing diffraction compared to constant line spacing. It has become apparent that randomness in line spacing is good for reducing diffraction effects. Although a gradient pattern in the line spacing can reduce diffraction, this is not as effective as random variation in line spacing. For example, if the line spacing alternates between a random low value and a random high value, diffraction is reduced the most. The diffraction effects can be further suppressed by branching the lines.

[0179] The selection of effective electrode patterns can be achieved by computer. For example, a large number of electrode patterns can be automatically generated and diffraction parameters can be calculated for them, which indicate the severity of the diffraction effect. Other parameters can also be calculated, for example, a homogeneity parameter representing the uniformity of the electric field can be calculated. Among the generated electrode patterns, an effective pattern can be selected based on the computer parameters.

[0180] Figure 3 An example of an embodiment of a substrate 300 is schematically shown. Figure 3 FIG. 1 shows a main line, which is composed of a series of connected sub-main lines, and branch lines extend from the sub-main lines. The sub-main lines may correspond to the reference Figure 2b mentioned, but this is not necessary. For example, Figure 2b A section in may include multiple sub-main lines.

[0181] Figure 3 3 shows a main line 301, which includes two sub-main lines 322 and 312 and a connecting portion 311. Dashed boxes 320 and 310 show a sub-main line and several branch lines. Such a box can be selected as a unit, for example, repeated as a unit, or selected from a plurality of units (for example, randomly), etc.

[0182] Figure 3 One advantage of the modular design is that many parameters of the branch lines can be selected simultaneously. For example, branch lines extending on the same side of a sub-main line can be equal lengths, and branch lines extending on the same side of a sub-main line can be parallel. In addition, the number of branch lines extending from either side of a sub-main line can be equal. These options make it easier to choose a more efficient design because there are fewer parameters to control. For example, a sub-main line and its branch lines selected in one place can be repeated in other locations.

[0183] On the other hand, Figure 3 The design of the sub-main line still allows for significant variations. For example, the branch lines extending from the same side of a sub-main line and the branch lines extending from subsequent sub-main lines of the same main line can have different lengths and be at different angles to the first direction. Both options are Figure 3 Different sub-main lines may also have different numbers of branch lines extending from one side of the sub-main line; this is not shown in Figure 3 . The angle between the main line or the branch line in the sub-main line and the first direction can be randomly selected between the minimum angle and the maximum angle, for example, randomly selected between 45 degrees and 90 degrees, etc. It should be noted that the sub-main line 322 and the sub-main line 312 are shifted relative to each other in both the first direction and the second direction. Fixing certain parameters in the dashed box significantly reduces the workload of the selection without having a high impact on the results that can be achieved.

[0184] In one embodiment, the line width can be selected from the range of about 1 micron to 50 microns. The line gap can be selected from the range of about 40 microns to 100,000 microns. For example Figure 3 The length of the sub-main line in, or e.g. Figure 2b The length of the parts in can be related to the line gap. For example, their length can be selected to be, for example, 5 to 10 times the line gap as measured from the first direction. In general, different values ​​are also possible, but these options should prove effective. Figure 2a to Figure 2c The branch lines are not shown, but in one embodiment, they may be present. The number or portion of branch lines of the sub-main line may also vary, for example from 3 to 10.

[0185] Varying line spacing without branch lines can also reduce diffraction effects, but combining these options is better. In fact, a substrate can be created that does not use branch lines. One embodiment of such a substrate is a substrate (100) for smart glass, wherein a first electrode (110) and a second electrode (120) are applied to the same side of the substrate, each of the first and second electrodes is arranged in a pattern across the substrate, the first and second electrodes each include main lines (111-113, 121-123) of a first multiplex system and a second multiplex system extending across the substrate in a first direction (101), the main lines of the first multiplex system and the main lines of the second multiplex system of the first and second electrodes are arranged alternately on the substrate relative to each other, wherein the distance between the main lines (201, 202, 203) on the substrate of the first electrode (201, 203) and the adjacent or subsequent main lines (202, 203, 204) varies in the second direction and / or in the first direction. Due to the variation in line spacing, the diffraction of such a substrate is reduced. The substrate may be combined with the features described herein, particularly with respect to line spacing.

[0186] Most of the drawings show the main line as a straight line, or as a combination of multiple straight sub-main lines. However, this is not necessary. For example, as shown in PCT / EP2020 / 052379, the main line can be wavy, for example sinusoidal. Figure 4a An embodiment of a substrate including a plurality of main lines is schematically shown, wherein the main lines are wavy. Figure 1a Or as shown in 1d, the main circuit is connected to two or more electrodes. Figure 4a The embodiment does not include branch lines, but the branch lines can also be incorporated into the wavy main line. In this case, since the distance between the main lines is not fixed along the line, it becomes more challenging to manage the position, angle and length of the branch lines. With the increase of design variability, diffraction can be further reduced. Figure 4b A schematic diagram of a substrate is given, where branch lines are combined with non-straight, e.g. wavy, main lines. The branch lines are not necessarily straight lines either.

[0187] When using a wavy main line, uniformity can be improved and hot spots can be reduced even without overlapping branch lines. An embodiment of such a substrate is a substrate (100) for use in smart glass, wherein a first electrode (110) and a second electrode (120) are applied to the same side of the substrate, each of the first electrode and the second electrode 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 across the substrate in a first direction (101), the plurality of main lines of the first electrode and the second electrode are alternately arranged on the substrate, a plurality of branch lines (131-134, 141-144) extend from the main lines to areas between the main lines, the branch lines (142, 132, 141, 131) extend to an area (150) between a second main line (112) of the first electrode and a first main line (121) of the second electrode, and the branch lines (142, 132, 141, 131) extend alternately from the first main line and the second main line, wherein one or more of the main lines, or all of the main lines are wavy.

[0188] Figure 4c An example of an embodiment of a substrate 450 is schematically shown, wherein the pattern in which the first and second electrodes are arranged is subdivided into blocks extending across the substrate in the first and second directions. The blocks include a portion of the electrode pattern so that a larger pattern is constructed by combining the blocks. For example, each block may include a plurality of sub-lines that are a portion of the plurality of main lines of the first electrode and a plurality of sub-lines that are a portion of the plurality of main lines of the second electrode. The sides of the blocks may be, for example, between 1 mm and 10 mm. For example, the blocks may be 8 mm×8 mm.

[0189] The blocks can be arranged in some regular pattern, such as a checkerboard pattern, but can also be arranged in an unusual pattern, such as Figure 4c The pattern arrangement shown. The blocks can be rectangular. The advantage of using blocks is that they can be repeated multiple times on the substrate, for example, advantageous blocks with particularly low diffraction effects and / or particularly good uniform electric fields.

[0190] One or more of the blocks include modes according to the embodiment, but some blocks may also include other modes, for example, including Figure 4a The pattern shown has no branch lines. Some of the main lines in a block may be straight, some may be wavy. Some may have branch lines, some may not, etc.

[0191] Interestingly, manipulation of the shape of the lines at a microscopic level, such as shown in various embodiments herein, can affect parameters such as diffraction and uniformity, but can also have a significant optical impact after disturbing the geometry of the design at a larger scale. Therefore, various electrode shapes produced as blocks can be combined at different levels. From a block construction perspective, blocks can be created at different levels, for example, blocks can be created at various levels of randomization while the size of the pattern increases. In particular, it is convenient, although not necessary, if the number of lines in a block is a multiple of 2.

[0192] In one embodiment, the electrodes are driven by a circuit with a limited number of voltage sources (e.g., 4 voltage sources). In one embodiment, the number of voltage sources is equal to the number of electrodes, wherein the number of electrodes on a given substrate may exceed two. In one embodiment, multiple circuits on the substrate are divided over more than 2 electrodes, or even more than 4 electrodes, or even more electrodes. Preferably, the number of main circuits on each electrode is substantially equal. For example, in one embodiment, multiple segments are arranged on the substrate, each segment being controlled by at least 2 electrodes of the substrate, and being controlled by at least 4 electrodes in an assembly of at least 2 substrates. By driving the corresponding electrodes, different optical effects can be arranged on different segments. It is not necessary to constrain the fluid to one segment, although this can be done when the segments are isolated from each other, so that different fluids can then be provided to each segment.

[0193] Figure 5a Several examples of embodiments of a substrate having an electrode pattern according to an embodiment are schematically shown. Figure 5a The embodiments shown are to scale and can be expanded to include complete electrode patterns, such as interleaved patterns.

[0194] Figure 5b Examples of embodiments of substrates with two electrode arrangements or three electrode arrangements are schematically shown. Figure 5b On the left side of the diagram, the letters 'a' or 'b' are used to indicate which main lines belong to the same electrode. All lines marked with 'a' are electrically connected, although this is not shown in the diagram. Figure 5a or Figure 5b This is shown in detail in the electrode pattern shown; similarly, this is also true for main line 'b'. Figure 5b To the right of the , the letters 'a', 'b' or 'c' are used to indicate which main lines belong to the same electrode. All lines marked with the same letter are electrically connected.

[0195] Figure 6a and Figure 6b A comparative example of two substrates is schematically shown. Figure 6c to Figure 6dExamples of two embodiments are shown. The diffraction pattern has been simulated. The simulation of the diffraction pattern itself is known in the art.

[0196] The diffraction level was calculated according to the method cited in "Numerical comparison of grid pattern diffraction effects through measurement and modeling with OptiScan software" by Murray et al., published in SPIE on May 20, 2011 (doi: 10.1117 / 12.883422). The method includes calculating the power spectrum of an image representing the electrode pattern, where the electrodes are drawn black on a white background. From the raw power spectrum, the diffraction level is calculated as the ratio of the maximum intensity of the higher order diffraction to the intensity of the zero order diffraction.

[0197]

[0198]

[0199] On the left Figure 6a A simple pattern is shown which comprises only a number of straight main lines which are connected together in an electrode, for example two electrodes in a staggered form. Figure 6b The pattern has additional orthogonal straight lines to make it orthogonal. Note that rotating the pattern will not help, as this will just rotate the diffraction pattern. Figure 6c and Figure 6d Examples of embodiments of substrates are schematically shown. Figure 6c Variable line gaps and varying angles were used, and there were shifts in the sub-main lines. Figure 6d A higher density of block variations was used, i.e. a greater number of vertical blocks along the line. Figure 6c Three blocks are shown, with the main line changing direction three times. Figure 6d With 10 blocks, the main line changes direction 10 times. It should be noted that the numerical ratio of the maximum diffraction value of 6c and 6d is Figure 6a and Figure 6b Such a straight line design is much lower.

[0200] Figure 6b The pattern not only has unfavorable diffraction values, but also has a tendency to develop hot spots between the opposing branches. In the area between the ends of the opposing branches, the electric field is much higher than elsewhere. The result is an inhomogeneous appearance in the opaque state and non-uniform switching speeds.

[0201] Figure 4a The wavy line design gives Figure 6cThe branch line design provides a more uniform electric field than the wavy line design.

[0202] According to one embodiment, two substrates can be combined into a light modulator. The light modulator is particularly suitable for glass. The following is an exemplary embodiment of a light modulator.

[0203] Figure 7a An embodiment of a light modulator 10 applicable to smart glass is schematically shown.

[0204] Reference is made to patent application PCT / EP2020 / 052379, which is included herein by reference; this application comprises advantageous designs of light modulators, which are further improved, for example, by including electrodes and / or branch lines as explained herein.

[0205] The optical modulator 10 is capable of bidirectional electronic switching between a transparent state and a non-transparent state, or bidirectional electronic switching between a reflective state and a non-reflective state. The optical modulator 10 includes a first substrate 11 and a second substrate 12 arranged opposite to each other. At least two electrodes are applied on the inner side of the first substrate 11: shown as electrodes 13a, 13b. These at least two electrodes are collectively referred to as electrodes 13. At least two electrodes are applied on the inner side of the second substrate 12: shown as electrodes 14a, 14b. These at least two electrodes are collectively referred to as electrodes 14.

[0206] A fluid 15 is disposed between the substrates. The fluid includes particles 30 (e.g., nanoparticles and / or microparticles), wherein the particles are charged or can be charged. For example, the surface of the particles can inherently carry a charge. For example, the particles can be surrounded by charged molecules.

[0207] The electrodes are arranged to drive the particles 30 to move towards or away from the electrodes, depending on the applied electric field. The optical properties, in particular the transparency or reflectivity of the light modulator, depend on the position of the particles 30 in the fluid. For example, connections for applying an electromagnetic field to the electrodes may be provided.

[0208] In one embodiment, substrates 11 and 12 are optically transparent outside the electrodes, typically with a transparency of >95% for the relevant wavelengths, such as a transparency of >99%. If the electrodes are taken into account, the transparency can be much lower, for example, 70%. The term "optical" can refer to wavelengths visible to the human eye (about 380nm to about 750nm), and can refer to a wider range of wavelengths, including infrared (about 750nm to 1μm) and ultraviolet (about 10nm to 380nm) wavelength ranges, if applicable, and sub-selections of the above wavelength ranges. In an exemplary embodiment of the light modulator, the substrate material is selected from glass and polymers.

[0209] In another embodiment, the substrates, such as the bottom substrate 12, can be reflective or partially reflective, while the top substrate 11 is transparent. The optical properties, in particular the reflectivity of the light modulator, depend on the position of the particles 30 in the fluid. When the panel is in the open state (vertically driven), the particles are mostly located between the opposing electrodes of the two substrates, so that the incident light can pass through the transparent top substrate and the optical layer relatively unimpeded, and is reflected or partially reflected on the bottom substrate.

[0210] 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, even more preferably less than 50 μm, such as less than 30 μm.

[0211] In one embodiment, the modulator may be provided in the form of a flexible polymer and the rest of the device may be provided in the form of glass. The glass may be rigid glass or flexible glass. If desired, a protective layer may be provided on the substrate. If more than one color is to be provided, more than one flexible polymer layer may be provided. The polymer may be polyethylene naphthalate (PEN), polyethylene terephthalate (PET) (optionally with a SiN layer), polyethylene (PE), etc. In another embodiment, the device may be provided in the form of at least one flexible polymer. Thus, the modulator may be attached to any surface, for example by using an adhesive.

[0212] The particles 30 may be adapted to absorb light, thereby preventing certain wavelengths of light from passing through. The particles 30 may reflect light; the reflection may be specular, diffuse, or somewhere in between. The particles may absorb certain wavelengths and reflect others. The particles may also or instead emit light using, for example, phosphorescence, fluorescence, etc. Even fluids may emit light, the emissivity of which is modulated by changing the position of the particles.

[0213] In an exemplary embodiment of the light modulator, the size of the nanoparticles is 20nm to 1000nm, preferably 20nm to 300nm, more preferably less than 200nm. In an exemplary embodiment of the light modulator, the nanoparticles / microparticles may include a pigment coating, and preferably include a core. In an exemplary embodiment of the light modulator, the material made of the particle coating is selected from a conductive material and a semiconductive material.

[0214] In an exemplary embodiment of the optical modulator, the particles are suitable for absorbing light with a wavelength of 10nm to 1mm, such as 400nm to 800nm, 700nm to 1μm, and 10nm to 400nm, and / or suitable for absorbing a portion of light (filter) in the wavelength range of 10nm to 1mm, and combinations of the above.

[0215] In an exemplary embodiment of the light modulator, the particles are charged or can be charged. For example, the charge on the particles can be 0.1e to 10e (5*10 -7 to 0.1C / m2).

[0216] In an exemplary embodiment of the light modulator, the amount of fluid present is 1 g / m2 to 1000 g / m2, preferably 2 g / m2 to 75 g / m2, more preferably 20 g / m2 to 50 g / m2, such as 30 g / m2 to 40 g / m2. A great advantage is that in the arrangement of the invention, less fluid can be used, and likewise less particles can be used.

[0217] In an exemplary embodiment of the light modulator, the particles are present in an amount of 0.01 g / m2 to 70 g / m2, preferably 0.02 g / m2 to 10 g / m2, such as 0.1 g / m2 to 3 g / m2.

[0218] In an exemplary embodiment of the light modulator, the particles have a color selected from cyan, magenta, and yellow, and selected from black and white, and selected from combinations of the foregoing colors.

[0219] In an exemplary embodiment of a light modulator, the fluid includes one or more of a surfactant, an emulsifier, a polar compound, and a compound capable of forming hydrogen bonds.

[0220] The fluid 15 may be a polar fluid with a dielectric constant less than 15. In an exemplary embodiment of the light modulator, the relative permittivity εr of the fluid is less than 100, preferably less than 10, such as less than 5. In an exemplary embodiment of the light modulator, the fluid 15 has a dynamic viscosity higher than 10 mPa.s.

[0221] The electrodes 13a, 13b and electrodes 14a, 14b are in fluid contact with the fluid. The fluid may be in contact with the electrodes directly or indirectly, for example, the fluid may be in contact with the second medium of the electrodes, such as through a porous layer. In one embodiment, the electrodes cover about 1% to 30% of the substrate surface. In one embodiment, the electrodes include a conductive material having a resistivity of less than 100 nΩm (for comparison, the commonly used ITO has 105 nΩm at 273K, which is similar to the conductivity of >1*10 at 20°C). 7 S / m). In one embodiment, the light modulator electrode comprises: copper, silver, gold, aluminum, graphene, titanium, indium, and combinations thereof, preferably copper. The electrode may be embedded in a polymer substrate in the form of microwires (e.g., copper microwires).

[0222] A connection for applying an electromagnetic field to an electrode, wherein the electromagnetic field applied to the electrode causes nanoparticles and microparticles to move from a first electrode to a second electrode, and from the second electrode to the first electrode. A connection for applying an electromagnetic field to an electrode can be provided. For example, in an exemplary embodiment of the optical modulator, the current is between -100 μA and +100 μA, preferably between -30 μA and +30 μA, and more preferably between -25 μA and +25 μA. For example, a power supply can be electrically connected to at least two electrodes. The power supply is suitable for providing waveform power. At least one of amplitude, frequency and phase is suitable for providing different states for the optical modulator. For example, various aspects of the power supply can be adjusted by a controller.

[0223] The light modulator 10 may comprise one or more segments, a segment being a single optically switchable entity, the size of which may vary.The volume enclosed by the substrate may be a segment, or at least a part of a segment.

[0224] The device may include a drive circuit that changes the appearance of a (single) segment by applying an electromagnetic field. Thus, the appearance of the light modulator or one or more parts thereof may also be changed. For example, the segment may have a diameter of at least 1 mm. 2 This allows stacking of the present design to achieve more colors; for example, for full-color applications, two or three modulator stacks can provide most or all colors, respectively.

[0225] Having one or more segments allows the light modulator to be controlled locally; this is advantageous for some applications, but is not required. For smart glass, the light modulator can be used with or without segments. For example, when applied to smart glass, transparency or reflectivity can be controlled locally, such as blocking sun spots without reducing the transparency or reflectivity of the entire window. The segments can be relatively large, such as having a diameter of at least 1 mm, or at least 1 cm, etc.

[0226] In an exemplary embodiment of the light modulator, the substrates (11, 12) are aligned, and / or the electrodes (13, 14) are aligned. For example, electrodes 13a, 13b and electrodes 14a, 14b can be aligned to face each other. In the aligned substrates, the electrodes on different substrates touch each other when viewed from a direction orthogonal to the substrates. When the light modulator is disassembled, both substrates are arranged with the electrodes facing upwards, and the electrode patterns are mirror images of each other.

[0227] Aligning the substrates can increase the maximum transparency or maximum reflectivity of the light modulator. On the other hand, when the selection criteria for the light modulator are more than the transparency range or the reflectivity range, two substrates that are not aligned or not fully aligned may be better. The light modulator can be stacked. For example, two stacked light modulators can be made of three substrates, wherein the middle substrate has electrodes on both of its surfaces. In an embodiment of the light modulator, optionally at least one substrate 11, 12 of the first light modulator is the same as the substrate 11, 12 of at least one second light modulator. Also for stacked modulators, alignment can increase the maximum transparency or maximum reflectivity, but may be detrimental to other considerations (e.g., diffraction).

[0228] Figure 7b An example of an embodiment of a light modulator 40 is schematically shown. The light modulator 40 is similar to the light modulator 10, except that it includes a plurality of optical layers; in the example shown, two optical layers. There may also be more than two optical layers. Each optical layer is arranged between two substrates. The light modulator 40 may be viewed as a Figure 7a As shown in the figure, 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 the substrate 41 and the substrate 42, and there is an optical layer between the substrate 42 and the substrate 43. The optical layer can be similar to the optical layer in the optical modulator 10. The controller 46 is configured to control the current of the electrodes of the substrates. For example, in Figure 7b In the embodiment, the controller 46 can be electrically connected to at least 8 (4 times 2 equals 8) electrodes.

[0229] Interestingly, the particles in multiple optical layers can be different, so that multiple layers can be used to control more optical properties of the light modulator. For example, particles in different optical layers can absorb or reflect different wavelengths, for example, can have different colors. This enables the creation of different colors and / or different color intensities on the panel by the controller 46. For example, a four-substrate panel can have three optical layers with particles of different colors (e.g., cyan, yellow, and magenta). By controlling the transparency or reflectivity of different colors, a wide spectrum of colors can be created.

[0230] For example, in one embodiment, the substrate surface facing the other substrate may be provided with two or more patterns. For example, the outer substrates 41 and 43 may receive electrodes only on the inner side, while the inner substrate (e.g., substrate 42) may have electrodes on both sides.

[0231] The substrate 41 and the substrate 42 can be used together as an embodiment of a light modulator. Similarly, the substrate 42 and the substrate 43 can be used together as an embodiment of a light modulator.

[0232] Figure 7c An example of an embodiment of a car 20 with a smart glass window 21 is schematically shown. This is a particularly advantageous embodiment because during driving, the level of incident light can change frequently and rapidly. A benefit of using smart glass in a car is that by adjusting the transparency of the window, the light level can be kept at a constant level. In addition, the reduced diffraction effect improves safety because the reduced diffraction effect reduces the distraction of the driver. The car 20 may include a controller configured to control the transparency or reflectivity of the window 21.

[0233] Smart glass can also be used in other glass applications, especially where the amount of incident light is variable, such as buildings, offices, houses, greenhouses, and skylights. Skylights are windows placed in the ceiling to allow sunlight to enter a room.

[0234] Figure 8a to Figure 8b A side view of an embodiment of a light modulator in use is schematically shown. Applying an electric field to the electrodes on the substrate causes the particles to be subjected to electric force. Using this effect, the particles can be moved, thereby enabling the light modulator to produce different transparency or reflectivity states. The controller can control the electric field, for example, the amplitude, frequency and phase of the electric field. In one embodiment, the controller is connected to at least four electrodes: two for each substrate. However, more electrodes can be used and connected to the controller; for example, the substrate can use more than 2 electrodes to better fine-tune the grayscale and drive to a non-transparent state or a non-reflective state. Multiple electrodes can also be used to support multiple segments on the substrate.

[0235] Figure 8a is shown for the light modulator without an applied electric field. Figure 8a In the present invention, no electric force is applied to the particles 30 suspended in the fluid 15.

[0236] exist Figure 8a In the configuration shown, the conductive electrode pattern arranged on the top substrate is completely or substantially aligned with the conductive electrode pattern on the bottom substrate. The conductive electrode pattern can be deposited on a transparent or (partially) reflective glass substrate, or embedded in a plastic substrate, etc.

[0237] Alignment between the top electrode pattern and the bottom electrode pattern helps to expand the range of achievable transparency levels or reflectivity levels. However, alignment is not necessary, as similar effects can be achieved without alignment. In the absence of alignment, a certain range of transparency or reflectivity can also be achieved.

[0238] Please note that in these examples, reference to the top substrate and bottom substrate refers to the substrate that is higher or lower on the page. The same substrates may also be referred to as, for example, the front substrate and the back substrate, because in glass applications, the substrates are arranged vertically rather than horizontally.

[0239] Figure 8b A light modulator is shown in which, for example in example P1, a potential +V1 is applied to each micro-wire electrode on the top substrate, while a negative voltage, such as -V1, is applied to each micro-wire electrode on the bottom substrate. Thus, in this case, the same positive potential is applied to all electrodes 13, while the same negative potential is applied to electrode 14. The difference in potential causes negatively charged particles to flow to the vicinity of the electrode of the top substrate, where the particles will be substantially aligned with the top electrode. As a result, if both the top substrate and the bottom substrate are transparent, the transparency of the light modulator 10 is improved. Similarly, if, for example, the top substrate is transparent and the bottom substrate is reflective, the reflectivity of the light modulator 10 is improved. If the solution contains positively charged particles, they will flow to the vicinity of the electrode of the bottom substrate, where the particles will be substantially aligned with the bottom electrode.

[0240] In the second example P2, similar transparency or reflectivity can be achieved when the voltages of the top and bottom electrodes are opposite to those of the example P1. In example P2, the voltage of each electrode of the top substrate is now provided with a negative potential -V1, while the voltage of the aligned electrodes of the bottom substrate is provided with a positive potential. This state is similar to Figure 8b , but the top substrate is exchanged with the bottom substrate. Also in this configuration, the transparency or reflectivity of the light modulator 10 is also high.

[0241] Interestingly, by placing a top substrate electrode (e.g. Figure 8b The positive potential of electrode 13 (and the negative potential of electrode 14) shown in FIG. 1 is related to the bottom substrate electrode (e.g., Figure 8b By switching between the positive potential of the electrode 14 shown in FIG. 1 , transparency or reflectivity can be maintained while reducing corrosion damage to the electrode. This alternating electric field can be achieved by applying alternating potentials to the top electrode and the bottom electrode.

[0242] The application of waveforms is optional and is an effective measure to increase the life of the optical modulator by reducing corrosion. For example, when copper electrodes are used, corrosion may form because copper ions are dissolved in the ionic fluid of one substrate and flow to the electrode of the opposite substrate and deposit there. By applying a waveform, the direction of copper ion transport is frequently reversed, thereby reducing corrosion damage. Between two instances P1 and P2, the corrosion current between the two substrates is balanced, or substantially balanced, such as >95% balanced, for example, with the corrosion rate of the electrode of the top plate occurring, and between each time instance, for example, in P1 or P2, there is a balanced copper deposition on the bottom electrode. Therefore, particles are continuously converted or migrated between the top electrode and the bottom electrode, and the optical modulator or smart window is always in the on state, and the dynamic electrolysis current between the top electrode and the bottom electrode is constant, so there is no net loss or a negligible net loss of electrode material on the top substrate and the bottom substrate.

[0243] Figure 8c It is shown how a reduced transparency state or a reduced reflectivity state can be obtained. Alternating voltages are applied to the same substrate. Figure 8c As shown, for example, in one embodiment, a potential +V2 is applied to the first electrode, and the next adjacent electrode has an opposite potential -V2, and so on. This can be achieved by applying a potential +V2 to electrode 13a and an opposite potential -V2 to electrode 13b. On the opposing substrate, a potential +V2 may be applied to electrode 14a, and an opposite potential -V2 may be applied to electrode 14b. For example, the electrodes may be arranged so that the electrodes on the substrates are aligned; an electrode on the top substrate has an opposite electrode on the bottom substrate, and vice versa. For example, to reduce transparency or reflectivity, opposing electrodes may receive the same potential, while adjacent electrodes receive opposite potentials. As Figure 8c An embodiment is shown in which four electrodes are indicated by reference numerals 13a, 13b, 14a and 14b, with the other electrodes continuing to alternate.

[0244] By using this AC drive cycle between the top and bottom substrates, a diagonal and lateral electric field is generated between the two substrates, which causes the particles to diffuse randomly, thereby establishing the closed state of the light modulator. As a result of this configuration, the particles migrate diagonally and laterally between the top and bottom substrates, and the diffusion of the particles into the visible aperture of the light modulator contributes to the closed, opaque state of the light modulator.

[0245] As for Figure 8b The transparent state shown, a waveform can be applied to the electrodes so that, for example Figure 8b The electrode with positive potential shown in the figure becomes negative potential, and the electrode with negative potential becomes positive potential. Figure 8bAs shown, for example, applying a waveform between electrodes 13a and 13b and between electrodes 14a and 14b can reduce corrosion damage to the electrodes.

[0246] By using a combination of Figure 5, Figures 6a to 6d The AC drive cycle can be achieved by the staggered line configuration of the top electrode and bottom electrode configuration shown in the isoplanatic view.

[0247] Figure 8b and Figure 8c The degree of increase or decrease in transparency or reflectivity depends on the voltage difference and the frequency difference. By changing the voltage difference, the amount of increase or decrease in transparency or reflectivity can be controlled. For example, a curve representing the change in transmittance relative to voltage can be determined (e.g., measured). In order to obtain a specific transmittance level (e.g., a specific transparency, a specific grayscale level), a corresponding voltage (e.g., an alternating voltage) can be applied. By interpolating the transparent state signal or the non-transparent state signal, a level between transparent and non-transparent can be obtained. Similarly, a curve representing the change in light reflection relative to voltage can be determined (e.g., measured). In order to obtain a specific reflectivity level, a corresponding voltage (e.g., an alternating voltage) can be applied. By interpolating the reflective state signal or the non-reflective state signal, a level between reflective and non-reflective can be obtained.

[0248] For the light modulator, different electrode patterns can be used. The electrode patterns can each provide a grayscale range (e.g., the transparency level or reflectivity level that the light modulator can achieve). However, the specific grayscale range of any particular electrode pattern may be different from other electrode patterns. In other words, although different patterns can give increased transparency or reflectivity or increased opacity, the exact response to the drive signal depends on many factors, including the specific pattern used. The change in the optical properties of the light modulator can have high resolution (e.g., resolution below 1 mm). It should be noted that different optical patterns (e.g., logos) visible in the light modulator can be achieved without the need for a pixelated light modulator.

[0249] This effect can be used to embed a visible image in a light modulator by locally changing the electrode pattern on the light modulator substrate. For example, due to the different electrode patterns, it is possible to have local grayscales with grayscales that are permanently offset relative to each other. For example, by locally changing the electrode pattern or its pitch, the maximum transparency or the maximum reflectivity can be changed.

[0250] The result is that regions on the light modulator have different grayscale intensities, e.g., different shades of gray, or colors. However, the regions may have the same color point. In one embodiment, the regions may switch together with the rest of the window, albeit at different rates. For example, even if the same voltage is applied to electrodes in two different regions, they may result in different transparent states (e.g., different levels of transmittance) due to the different electrode patterns. For example, a curve representing transmittance versus voltage change may be shifted. For example, if two regions change voltage control in the same way, the light transmittance of the two regions may change, but the amount of the change is different. A region may also be made less responsive to a drive signal by reducing the density of electrodes; in particular, a region may not switch at all, e.g., by not applying electrodes to the region.

[0251] This effect can be used to embed logos in light modulators. For example, Figure 9a One embodiment of a logo and a grid is schematically shown. Figure 9a As shown, the first group of grid blocks intersects with the logo, and the second group of grid blocks does not intersect with the logo. For the first group that intersects, a different electrode pattern can be used than for the second group of grid blocks. Figure 9b An example of an embodiment of a substrate is schematically shown. The area indicated by the first set of grid blocks may have a different electrode pattern embedded (e.g., Figure 7a The first substrate and the second substrate are formed by the substrate in the embodiment of the present invention. Figure 9b As shown, the two regions have different transmittances.

[0252] Figure 9c to Figure 9d An example of an embodiment of a light modulator is schematically shown. Fig.9c As shown, the substrate is in a non-transparent configuration; in the region indicating the logo, the electrode pattern is adjusted so that it provides a lower darkening efficiency for the light modulator. Figure 9d , the same substrate in a more transparent configuration. Note that the transmittance of both the logo and non-logo areas increases, albeit at different scales. Figure 9d The area indicating the logo is still visible, although now its transmittance is closer to that of the other areas.

[0253] Interestingly, this effect can be achieved simply by using a different pattern (e.g., by changing the pitch and / or design of the electrodes). There is no need to change the waveform / current / voltage / power in this area compared to other areas.

[0254] There are many applications for embedding images in light modulators, especially smart glass. For example, content (such as logos, brands, etc.) can be embedded. Textures can be embedded into the glass. Contrast can be embedded into the glass. Other options include emergency exit signs, such as arrows, etc.

[0255] For example, for a shop / restaurant window: a completely dark window may indicate that the shop is closed, whereas when the shop is open a logo or any other designated design is visible. The pattern may be a logo or the like, but this is not required. The embedded image may be a pattern that prevents passers-by from looking into the window while still providing sufficient light inside. In particular, the embedded image need not contain readable information. For a car window, the glass may be completely dark when the car is closed (e.g. parked), whereas a logo may appear when the car is opened, e.g. a manufacturer's logo.

[0256] By adjusting the design parameters, specific local optical differences compared to the background will be made visible without changing the electrical drive. Electrode pattern parameters that affect the optical performance include:

[0257] -Electrode line gap

[0258] -Electrode line thickness

[0259] -Electrode circuit shape

[0260] -Electrode line direction

[0261] - Local variations in the cell gap, e.g., variations in the distance between the substrates

[0262] -Distribution of branch line lengths.

[0263] For example, the gap, thickness, shape, and orientation of the electrode lines have an impact on the local transparency level and response time; the gap / width of the electrode lines has an impact on the local diffraction level, which also makes local optical differences. Changes in the cell gap will change the level of the dark state, which in turn changes the maximum transparency or reflectivity and the response time. Another option is to change the diffraction effect between two areas. For example, an area such as mostly glass can have an electrode pattern with a low diffraction effect, while an area with an embedded image can have an electrode pattern with an intentionally high diffraction effect.

[0264] Optical properties (including transparency or reflectivity) can also be changed by changing the electrode material; for example, by selecting electrode materials with different optical properties and / or conductive properties. The electrode material may affect the diffusion, reflection and diffraction of light, resulting in additional optical effects. If the conductivity of the electrode material is changed locally, it will affect the potential at that location, thereby affecting the electric field and, in turn, the transparency level or reflectivity level.

[0265] For example, the electrode material can be copper, aluminum, gold, indium tin oxide (ITO), etc. ITO is transparent, while copper / aluminum is reflective, so using different electrode materials, different appearances can be obtained, regardless of the driving voltage. Similarly, different materials have different resistances and will induce different electric fields. For example, even if the same voltage is used to drive, ITO will have a smaller electric field.

[0266] Another method of obtaining a variable transparency or reflectivity is to locally change the spacer applied between the first substrate and the second substrate. For example, different spacers can have different optical properties and densities. For example, spacers of different sizes with different transparencies can be used. The density of the spacers can be different. In one embodiment, the density of the spacers can even be increased by 1000x, which will produce a significantly different appearance. The increase can also be less than 1000x. The spacers can also be adapted to intentionally change the distance between the substrates, thereby changing the appearance of the substrates.

[0267] The various options for locally changing the appearance of a region of a light modulator without changing the drive in that region can be applied to light modulators with a single layer (e.g., one fluid layer, two substrates), but can also be applied to multilayer light modulators with multiple fluid layers and more than two substrates. The latter can be used to produce multiple colors.

[0268] The pattern in which the first and second electrodes are arranged is subdivided into a plurality of sections. There may be two sections, each with different optical properties, for example due to different electrode patterns, or there may be a plurality of sections. This may be used, for example, to apply an image with multiple shades of grey rather than just black and white.

[0269] In order to embed a logo, it is not necessary to use a substrate according to one embodiment. For example, a favorable substrate that can be used for smart glass includes a first electrode and a second electrode, and the first electrode and the second electrode are applied to the same side of the substrate. Each of the first electrode and the second electrode is arranged in a pattern across the substrate, and the first electrode and the second electrode each include a plurality of main lines extending across the substrate in a first direction, and the plurality of main lines of the first electrode and the second electrode are arranged alternately relative to each other on the substrate. The pattern in which the first electrode and the second electrode are arranged can be subdivided into a plurality of parts, wherein at least one of the electrode line gap, the electrode line thickness, the electrode material, the electrode line shape, and the electrode line direction is different in the plurality of parts, resulting in different maximum transparency or reflectivity or saturation.

[0270] Such a substrate with embedded logo (with or without branch lines) or an optical modulator comprising such a substrate may be combined with other features described herein.

[0271] Fig.10An example of an embodiment of a method for controlling an optical modulator according to an embodiment is schematically shown. The method 500 may be implemented by a computer. The method 500 includes:

[0272] - selecting (510) an alternating current of one of a plurality of maximum amplitudes, said alternating current corresponding to one of a plurality of transparency levels in the light modulator,

[0273] - applying (520) said alternating current to the electrodes to obtain an electromagnetic field between the electrodes, said electromagnetic field providing the particles with electrophoretic movement towards or from the electrodes.

[0274] There are many different ways to perform the method, which will be apparent to those skilled in the art. For example, the order of the steps can be performed in the order shown, but the order of the steps can also be changed, or certain steps can be performed in parallel. In addition, other method steps can be inserted between steps. As described herein, the inserted steps can represent improvements to the method, but can also be unrelated to the method. For example, certain steps can be performed at least partially in parallel. In addition, a given step may not be fully completed before the next step is started.

[0275] The electrodes may be driven using a signal having a selected maximum amplitude corresponding to one of a plurality of transparency levels or reflectivity levels of the light modulator. The signal may be an alternating current or an alternating voltage.

[0276] Embodiments of the method may be performed using software comprising instructions for causing a processor system to perform method 500. The software may include only those steps taken by a particular sub-entity of the system. The software may be stored in a suitable storage medium (such as a hard disk, a floppy disk, a memory, an optical disk, etc.). The software may be sent as a signal along a wired or wireless connection, or using a data network (e.g., the Internet). The software may be available for download and / or available for remote use from a server. Embodiments of the method may be performed using a bitstream, which is arranged to configure programmable logic, for example, a field programmable gate array (FPGA), to perform the method.

[0277] It is to be understood that the subject matter disclosed herein also extends to computer programs, particularly computer programs on or in a carrier, suitable for implementing the subject matter disclosed herein. The program may be in the form of source code, object code, code intermediate source, and the object code may be in the form of a partial compilation, or any other form suitable for implementing the embodiment of the embodiment of the method. An embodiment related to a computer program product includes computer executable instructions corresponding to each processing step of at least one method described. These instructions may be subdivided into subroutines and / or stored in one or more files, which may be linked statically or dynamically. Another embodiment related to a computer program product includes computer executable instructions corresponding to each device, unit and / or part of at least one system and / or product described herein.

[0278] Fig.11a A computer readable medium 1000 having a writable portion 1010 is shown, the readable medium 1000 including a computer program 1020, the computer program 1020 including instructions for causing a processor system to perform a light modulator method according to one embodiment. For example, the processor system can be connected to a light modulator panel. The computer program 1020 can be implemented on the computer readable medium 1000 as a physical mark or by magnetization of the computer readable medium 1000. However, any other suitable implementation is also conceivable. In addition, it is understood that although the computer readable medium 1000 is shown as an optical disk, the computer readable medium 1000 can be any suitable computer readable medium, such as a hard disk, a solid state memory, a flash memory, etc., and can be non-recordable or recordable. The computer program 1020 includes instructions for causing a processor system to perform the light modulator method.

[0279] Fig.11b In a schematic representation a processor system 1140 is shown according to an embodiment of an implementation of a controller of an optical modulator. The processor system comprises one or more integrated circuits 1110 . Fig.11bThe architecture of one or more integrated circuits 1110 is schematically shown. The circuit 1110 includes a processing unit 1120 (e.g., a CPU) for running a computer program component to execute a method according to an embodiment and / or a module or unit implementing an embodiment. The circuit 1110 includes a memory 1122 for storing programming code, data, etc. A portion of the memory 1122 may be read-only. The circuit 1110 may include a communication element 1126 (e.g., an antenna, a connector, or an antenna and a connector, etc.). The circuit 1110 may include a dedicated integrated circuit 1124, which is used to perform a part or all of the processing defined in the method. The processor 1120, the memory 1122, the dedicated IC 1124, and the communication element 1126 may be connected to each other via an internal connection 1130 (e.g., a bus). The processor system 1110 is arranged for contact communication and / or for contactless communication by using an antenna and / or a connector, respectively.

[0280] For example, in one embodiment, the processor system 1140, for example, the device may include a processor circuit and a memory circuit, and the processor is arranged 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 one embodiment, the processor circuit may be an ARM Cortex M0. The memory circuit may be a ROM circuit, or a non-volatile memory (e.g., flash memory). The memory circuit may be a volatile memory (e.g., an SRAM memory). In the latter case, the device may include a non-volatile software interface (e.g., a hard disk, a network interface, etc.) arranged to provide software.

[0281] A controller for an optical modulator, for example a controller for controlling the voltage applied to an electrode, may comprise a processor circuit, but may also or instead comprise a state machine.

[0282] Figures 12 to 37 Examples of implementation schemes of light modulators are schematically shown. In these figures, the voltages that can be applied to the electrodes are represented by reference voltages V1, V2, ... to indicate the voltages that can be applied to the electrodes. The voltages indicated by different reference voltages are usually different, although they can also be equal. The electrodes can be driven using a signal with a selected maximum amplitude. Using different voltages for one of the electrodes, or some of the electrodes or all of the electrodes will result in significant differences in the panel, in particular different optical properties, which depend on specific, for example, different transparencies. For example, the signal amplitude can be selected from a plurality of maximum amplitudes to achieve one of a variety of transparencies. The signal can be an alternating current or an alternating voltage.

[0283] The positive or negative sign indicates whether the voltage is positive or negative relative to the zero voltage. Another example of the same embodiment can be obtained by replacing all positive signs with negative signs, and vice versa.

[0284] As an embodiment, the different reference voltages may be equal (except for sign), except for corrections that are applied to account for manufacturing errors (e.g., slightly different electrodes, uneven substrates, etc.). As an embodiment, the differences in the different reference voltages create intermediate transparencies (e.g., different grays, or different colors or color intensities). As an embodiment, the intermediate voltages may be used to facilitate the dispersion or collection of particles. Although it is advantageous to use different reference voltages, advantageous light modulator embodiments may be obtained by selecting all or some of the reference voltages to be equal (except for sign).

[0285] Typically, the electrodes are driven from a DC neutral point, for example by applying an alternating current (AC) signal. In this regard, the reference voltage can be considered to be the maximum amplitude of the AC signal, while the positive and negative signs indicate the phase of the signal.

[0286] Therefore, (positive / negative sign indicates) the voltage sign is only applicable for a specific time period; the voltage sign of each electrode may be reversed in the next time period. These figures are not entirely to scale, for example, the substrate electrodes are not necessarily equidistant. The arrows in the figures show the main electric field lines.

[0287] The figure shows that the optical modulator includes a first substrate and a second substrate, with an optical layer between the two substrates. A plurality of electrodes are applied to the inner side of the substrates, each electrode including a plurality of main lines. In the figures, for clarity, the first substrate and the second substrate will also be referred to as the top substrate and the bottom substrate. However, it is not noted that the substrates can be in any position, so that the top and the bottom can be, for example, the front and the back. The electrodes in these figures do not show enhancements such as branch lines, although these enhancements can be applied.

[0288] A controller may be connected to the light modulator as shown to control the voltage generated on the electrode (eg, the voltage indicated by the reference voltage).

[0289] Note that various improvements described herein, such as branching lines, substrates with more than two electrodes, etc., are particularly advantageous when used in combination; for example, branching lines reduce diffraction, but this effect is enhanced when multiple electrodes reduce the curtain effect. However, these enhancements, as described below and elsewhere herein, also have undesirable advantages, such as a controller that is not configured to achieve one of multiple levels of transparency or reflectivity in a light modulator by using an alternating current of one of multiple maximum amplitudes. The embodiments below can be adapted to controllers that cannot be driven with alternating currents of different maximum amplitudes by selecting a voltage equal to the reference voltage indicated.

[0290] Figures 12 to 15 An example of implementation of a light modulator is schematically shown, which is applied with two electrodes on each substrate.

[0291] The device has at least 4 independent electrodes (e.g., wires), that is, at least 2 electrodes are arranged on each substrate, and the direction of the electric field can be modulated, as shown in the figure. It should be noted that the potential level of each electrode can be modulated. By using a single reference potential, a simplified optical modulator can be obtained.

[0292] Fig.12 One embodiment of driving a light modulator to increase transparency is shown.

[0293] Fig.13 An embodiment of driving the light modulator to reduce transparency is shown. Note that the diagonal lines are created to increase the dispersion speed of the particles. In addition, the particles are dispersed more toward the center of the light modulator, reducing the curtain effect.

[0294] Fig.13 and Fig.14 Two different ways of driving towards a darker state are shown. Fig.14 An embodiment of driving a light modulator is shown, in which both the vertical and lateral electric fields are enhanced. Which of the vertical and lateral electric fields is stronger, and thus drives the pigment, depends on the dimensions of the design (e.g., cell gap and line gap). If the distance between the electrodes is reduced, the electric field will be stronger, and the particles will move to the electric field area where the electric field is the strongest. If the electric field difference between the vertical field and the lateral field is not strong enough in this case, then in the case of a design that is uniform along the substrate, the light modulator will exhibit an intermediate open state.

[0295] In case of design variations in the light modulator and the distances between electrodes within the same substrate and between substrates are not constant along the light modulator, the areas of highest electric field, where the charged particles are locally concentrated, can change, leading to optical differences. In some areas, the light modulator can become more transparent, while in other areas, it can become less transparent even with uniform electrical drive. This effect is difficult to achieve with other drive methods, e.g. Fig.13 This effect can be used, for example, to embed a logo in a light modulator.

[0296] Fig.15 An embodiment using an alternating current of one of a plurality of maximum amplitudes is schematically shown. A first electrode on the top substrate is driven with a reference voltage of +V, while a second electrode on the top substrate is driven with a reference voltage of +V / 2. Opposing electrodes on the bottom electrode are driven with -V / 2 and -V, respectively. It should be noted that the voltage difference between opposing electrodes is + / -1.5V, while the voltage difference between adjacent electrodes is + / -0.5V. As a result, the particles will mostly react to the vertical field and align themselves to increase transparency, however this effect will be relatively small.

[0297] Fig.16 and Fig.17 Examples of various embodiments are schematically shown, where one substrate has 2 electrodes and the other substrate has 3 electrodes. In one embodiment, at least one of the first and second substrates is applied with at least 3 electrodes, while the other substrate is applied with at least two electrodes.

[0298] When additional electrodes are available, additional voltage combinations can be obtained. This provides more control over grayscale, for example. For example, with 5 electrodes instead of 4, addressing modes are possible that are not feasible in a four electrode system.

[0299] The substrate has at least three electrodes that can reduce curtain effects; for example, the visual effect of a curtain closing appears between the electrodes, rather than causing transparency to gradually increase or decrease uniformly. For example, one or more or all of the additional electrodes on one of the substrates can be used to close (reduce transparency) rather than open (increase transparency). The curtain effect itself is obviously distracting, but it also increases diffraction.

[0300] The benefit of having at least 3 electrodes on one substrate is that the electrodes can be closer together without reducing maximum transparency or reflectivity. For example, in one embodiment, the electrodes on a substrate having at least 3 electrodes can be 35 microns apart, while the electrodes on an opposing substrate having, for example, 2 electrodes can be 70 microns apart. These are exemplary numbers; actual numbers will vary as required.

[0301] Closely spaced electrodes together provide a stronger electric field, so a faster closing can be achieved, resulting in a reduced curtain effect. On the other hand, when opening, if the additional electrodes are configured not to attract particles, there is little loss in maximum transparency or reflectivity.

[0302] In one embodiment, the additional electrode may be made of a different material than the other electrodes (eg, a transparent material). For example, four electrodes may be made of copper, while the additional fifth electrode is made of ITO.

[0303] Fig.16 and Fig.17 An embodiment is shown in which the distance between subsequent main lines of multiple electrodes in the first substrate is greater than the distance between subsequent main lines of multiple electrodes in the second substrate. For example, as shown in the figure, the former distance can be twice the latter. For example, the former distance can be at least 2 times, at least 1.5 times, or at least 1.2 times, etc., of the latter.

[0304] Fig.16 and Fig.17 An embodiment driven to reduce transparency is shown.

[0305] Figure 18 to Figure 19 An example of an embodiment of a light modulator having three electrodes on each substrate is schematically shown.

[0306] Having at least three electrodes on each side improves on the advantages of having five electrodes. It is now possible to have closer electrodes on both sides without reducing transparency, since not all electrodes need to be opened on the device. In addition, the six electrodes can be arranged symmetrically, with three electrodes on each substrate.

[0307] Figure 20 to Figure 23 An example of an implementation of a light modulator is schematically shown with four electrodes on one substrate and two electrodes on another substrate. With a greater number of electrodes, the transparency can be further modulated and controlled by design rather than just by particle motion. Fig. 20 As described in , light modulator regions can be arranged to diffuse particles in the visible region, while other portions can be arranged to concentrate particles in the vertical field. This enables designs that can control grayscale. Fig.21 , Fig. 22 and Fig.23 Other embodiments are shown with potential linkage on 2 and 4 electrodes to modulate the grayscale.

[0308] Figure 24 to Figure 29 Examples of embodiments of light modulators with four electrodes per substrate are schematically shown. These embodiments allow further control over the grey scale.

[0309] Fig.30 Examples of implementations of light modulators are schematically shown. Fig.30 The light modulator in has two electrodes on each side, but can also be implemented with more than 2 electrodes.

[0310] Fig.30 The optical modulator shown in FIG. 1 also has a secondary electrode parallel to the primary electrode. For example, the primary electrode can be a main line or a branch line, etc. Fig.30 In the embodiment of the present invention, the primary electrode has been indicated with reference numeral 3001 and the secondary electrode has been indicated with reference numeral 3002. As shown, the secondary electrode extends along each primary electrode, but this is not required.

[0311] In one embodiment, the secondary electrode is connected to the primary electrode via a semiconductor layer, the secondary electrode being electrically connected to the primary electrode line by means of the semiconductor layer, the semiconductor layer allowing current to flow in the primary electrode only above a threshold voltage. Thus, voltage switching can be solved by potential.

[0312] Accordingly, the primary electrode or a portion thereof may be locally interconnected with the secondary electrode. By joining the layers of semiconductor material, the transparent electrode will only see the potential when a minimum potential is applied to the electrode. This may form a voltage switch at the surface, handled by the potential. The secondary electrode may be transparent. The second electrode may be the same or similar size as the primary electrode, or even larger.

[0313] In one embodiment, the secondary electrode comprises a capacitor arranged to hold a charge locally. This can be used to increase power. In order to arrange the extended electrode as a capacitor, no semiconductor layer is required.

[0314] In one embodiment, the secondary electrode comprises a photovoltaic semiconductor material, the secondary electrode providing power to the primary electrode circuit.

[0315] Figure 31 to Figure 33 An example of an embodiment of a substrate with two electrodes is schematically shown, wherein the two electrodes extend in two dimensions but are offset in a third dimension. The figures show a top view. The two electrodes are arranged in a plane, respectively, but the planes are offset relative to each other. The electrodes can be etched, for example.

[0316] The staggered pattern of electrodes on each substrate enables the light modulator to be set to a particle dispersion state (usually a dark state). The electric field parallel to the substrate will provide a high level of uniformity. The electric field distribution along the vertical axis (i.e., the axis from substrate to substrate) promotes particle concentration through field lines, which can be considered less uniform. This physical non-uniformity can be used to more easily create grayscale.

[0317] The offset between electrodes on the same substrate allows the angles between the staggered main lines to reduce diffraction levels. Complementary lines can be created to further reduce diffraction issues, and / or reduce parallax. In one embodiment, a passive matrix design is used.

[0318] Offsetting two electrode patterns by an angle can be applied between a substrate and an opposing substrate, but can also be applied between different patterns on different substrates. For example, electrode patterns on different substrates can be offset by an angle. For example, in one embodiment, two or more staggered electrodes can be applied to two parallel substrates, where the main lines of the two substrates are not parallel, but form an angle relative to each other.

[0319] Fig.34 Schematically shown are examples of embodiments of light modulators, wherein electrodes on a first substrate are at least partially arranged in the same pattern as second electrodes on a second substrate, wherein the first electrode pattern and the second electrode pattern are shifted relative to each other.

[0320] In the embodiment, a stagger based on a 6-electrode system is shown. The stagger reduces parallax effects due to production alignment tolerances. One specific way of driving the system is shown in the figure.

[0321] Specific misalignment can be applied globally to the device, or it can be applied only locally. For example, specific misalignment can be used at an edge to prevent unwanted movement of particles toward the edge, which is also known as the pigment migration effect. In one embodiment, the alignment at a specific location can be modified to better conform to future bending of the light modulator. Combining pattern misalignment and pattern alignment between substrates can improve optical effects (such as diffraction and / or parallax).

[0322] For example, in one embodiment, two or more staggered electrodes may be applied to two parallel substrates, where the main traces in the two substrates are parallel but displaced relative to each other.

[0323] Fig.35 An example of an embodiment of a light modulator having four electrodes per substrate is schematically shown.In one embodiment, different materials may be combined for the electrodes to reduce parallax.

[0324] For example, on each substrate, one of the two electrodes can be made metallic or transparent (e.g., ITO), or have different optical specifications. The electrode on the opposite substrate will be made of another type of material; for example, a transparent material can be opposed to a non-transparent material.

[0325] For example, in Fig.35In the 8-electrode system shown, the circled electrodes can be made transparent (e.g., ITO), while the other electrodes can be metal (e.g., copper) and non-transparent. This reduces the effect of alignment tolerance on parallax, even if the shape design of the horizontal electrodes needs to be perfectly aligned between the bottom substrate and the top substrate. The impact of manufacturing differences is small.

[0326] Figure 36 to Figure 37 Examples of embodiments of light modulators are schematically shown, the light modulators having different geometries along the substrates. For example, the geometry of the electrodes may differ on at least one of the first substrate and the second substrate, for example, differing in one or more of electrode thickness, width, shape, area, and volume.

[0327] The use of different electrode geometries can be combined with any kind of electrode structure.

[0328] In one embodiment, the electrodes do not have the same electrode height. Modifying the electrode height will affect both the electric field distribution and the liquid flow. Similarly, the electrode shape parallel to the substrate can be of any form. The electrode shape on the vertical plane can also have different shapes compared to the substrate, for example, it can be a rectangle with rounded corners and without rounded corners, a triangle, a trapezoid, etc.

[0329] Fig.36 An embodiment is shown in which the electrodes on the substrate have different heights. Fig.36 Also shown are embodiments where opposing electrodes on different substrates have different heights.

[0330] Fig.37 Embodiments are shown in which the electrodes on the substrate have different shapes. Fig.37 Also shown are embodiments where opposing electrodes on different substrates have different shapes.

[0331] An advantage of a taller electrode is that it is less susceptible to corrosion.

[0332] Figure 38 to Figure 39 An example of a physical contaminant causing an electrical short between electrodes in a prior art light modulator is schematically shown.

[0333] Fig.38 An example of a physical contaminant causing an electrical short between electrodes on opposing substrates in a prior art light modulator is schematically shown.

[0334] Fig.39 An example of a physical contaminant causing an electrical short between adjacent electrodes on a single substrate in a prior art optical modulator is schematically shown.

[0335] Figures 40 to 44 Examples of implementations of light modulators are schematically shown.

[0336] Figures 40 to 45 Examples of embodiments of light modulators are schematically illustrated, schematically showing various configurations of protective coatings and further illustrating how these configurations prevent physical contaminants (not part of the embodiment) from forming a short circuit between electrodes.

[0337] Fig.40 An embodiment of an electrode on a substrate provided with a protective coating covering the entire substrate is shown, such that both the electrode and the portion of the substrate not covered with the electrode are covered by the protective coating. Fig.40 Also shown are embodiments of opposing electrodes on different substrates that are not provided with a protective coating.

[0338] Fig.41 An embodiment is shown where the electrodes on both substrates are provided with a protective coating covering the entire substrate, such that both the electrodes and the portions of the substrate not covered with the electrodes (and in fluid contact with the fluid) are covered by the protective coating.

[0339] Fig.42 An embodiment of electrodes provided with a protective coating is shown, the protective coating being in a regular pattern or in a random pattern, wherein not necessarily all electrodes are covered. In this embodiment, a portion of the electrodes on the first substrate and the second substrate are covered with a protective coating.

[0340] Fig.43 An embodiment of electrodes provided with a protective coating is shown, the protective coating being in a regular pattern or in a random pattern, wherein not all electrodes are necessarily covered with the protective coating. In this embodiment, the protective coating is provided so that some (but not all) electrodes are covered with the protective coating, and at the same time, a portion (but not all) of the inner side surface of the substrate where no electrode is provided is covered with the protective coating. In this embodiment, the protective coating is provided on part of the electrodes of both substrates and on part of the inner side of the substrates.

[0341] Fig.44 An embodiment of electrodes provided with a protective coating is shown, the protective coating being in a regular pattern or in a random pattern, wherein not all electrodes are necessarily covered with the protective coating. In this embodiment, the protective coating is provided so that some (but not all) electrodes are covered with the protective coating, and at the same time a portion (but not all) of the inner side surface of the substrate where no electrodes are provided is covered with the protective coating. In this embodiment, the protective coating is provided on a portion of the electrodes and a portion of the inner side of the substrate of only one substrate, and not on the opposing substrate.

[0342] Fig.45An embodiment of electrodes provided with a protective coating is shown, the protective coating being in a regular pattern or in a random pattern, wherein not all electrodes are necessarily covered with the protective coating. In this embodiment, the protective coating is arranged so that some (but not all) electrodes are covered with the protective coating, and at the same time, a portion (but not all) of the inner side surface of the substrate where no electrode is provided is covered with the protective coating. In this embodiment, the protective coating is arranged on part of the electrodes and on part of the inner side of the substrates of both substrates. Fig.45 It is also shown that certain portions of the protective coating may have a different thickness than other portions of the coating.

[0343] Figure 46 to Figure 48 Schematically illustrated are examples of embodiments of substrates for use in light modulators having protective coatings of different geometries across the electrodes and the remainder of the substrate. For example, the geometry of at least one of the protective coatings across the first substrate and the second substrate can be different, for example, in one or more of the following aspects: shape (wire, grid, yarn), coating width, coating length, coating thickness, presence or absence of a protective coating on an opposing substrate, and alignment with a coating on an opposing substrate.

[0344] Fig.46 An embodiment of a top view of a single substrate (dashed line) is shown, to which an electrode (grey line) is applied, wherein a protective coating (black line) is applied on the electrode and on the surface of the substrate not provided with the electrode. In this embodiment, the protective coating is applied in a parallel stripe pattern, at an angle to the main line of the electrode.

[0345] Fig.47 An embodiment of a top view of a single substrate (dashed line) is shown, to which an electrode (grey line) is applied, wherein a protective coating (black line) is applied on the electrode and on the surface of the substrate not provided with the electrode. In this embodiment, the protective coating is applied in a mesh pattern, the main lines of which are displaced relative to the main lines of the electrode.

[0346] Fig.48 An embodiment of a top view of a bottom substrate (dashed line) is shown, to which an electrode (grey line) is applied, wherein a protective coating (black line) is applied on the surface of the electrode and the substrate not provided with the electrode. Also shown in this embodiment is that the protective coating (black line) is provided on the surface of the electrode applied to the top substrate (not shown), and is provided on the substrate surface of this top substrate not provided with the electrode. In this example, the protective coating in the form of parallel lines applied on the top substrate and the bottom substrate together form a mesh pattern, the main lines of which are inclined relative to the main lines of the electrode.

[0347] The following numbered clauses represent contemplated and non-limiting embodiments:

[0348] Clause 1. An optical modulator comprising:

[0349] - a first substrate and a second substrate, the inner sides of the first substrate and the second substrate being arranged opposite to each other,

[0350] - a plurality of electrodes are applied to the inner side of each of the first and second substrates, each of the first and second substrates having an inner surface area,

[0351] - wherein each of the plurality of electrodes is arranged in a pattern spanning the substrate, each of the plurality of electrodes comprises a plurality of main lines extending across the substrate in a first direction, and the plurality of main lines of the plurality of electrodes are alternately arranged on the substrate, and

[0352] - wherein at least a portion of said inner surface area of ​​at least one of said first substrate and said second substrate is provided with a protective coating;

[0353] - an optical layer between the first and second substrates, the optical layer comprising a fluid comprising particles, wherein the particles are charged or chargeable;

[0354] - a controller configured to apply an electric potential to the plurality of electrodes so as to obtain an electromagnetic field between the plurality of electrodes, thereby providing the particles with electrophoretic motion towards or away from one of the plurality of electrodes, resulting in modulation of the optical properties of the light modulator.

[0355] Clause 2. The light modulator of clause 1, wherein the protective coating is disposed on at least a portion of an inner surface area of ​​one of the first and second substrates, wherein an inner surface of the opposing substrate is not provided with a protective coating.

[0356] Clause 3. The light modulator of any of the preceding clauses, wherein the protective coating is disposed on at least a portion of the inner surface area of ​​the first and second substrates.

[0357] Clause 4. The light modulator of any of the preceding clauses, wherein the protective coating covers at least 1% of a total inner surface area of ​​at least one of the first and second substrates.

[0358] Clause 5. The light modulator of any of the preceding clauses, wherein the protective coating covers at least 1% of the total inner surface area of ​​the first and second substrates.

[0359] Item 6. An optical modulator according to any of the preceding items, wherein the inner side of one of the first substrate and the second substrate is completely provided with a protective coating, so that the entire surface of the multiple electrodes applied to the inner side and the inner side of the substrate where no electrodes are provided are basically provided with the protective coating, wherein the opposite substrate is not provided with a protective coating.

[0360] Clause 7. An optical modulator according to any of the preceding clauses, wherein the inner sides of the first substrate and the second substrate are completely provided with a protective coating, so that the entire surface of the multiple electrodes applied to the inner side and the inner side of the substrate where no electrodes are provided are basically covered with the protective coating.

[0361] Clause 8. A light modulator according to any of the preceding clauses, wherein the protective coating is provided as a patterned coating.

[0362] Item 9. An optical modulator according to Item 8, wherein a first main circuit on the first substrate is provided with the protective coating, while a second main circuit on the second substrate opposite to the first main circuit is not provided with the protective coating, and the second main circuit is in fluid contact with a fluid, and vice versa.

[0363] Clause 10. The light modulator of Clause 9, wherein the plurality of main lines on the first substrate and the second substrate are alternately provided with and without the protective coating.

[0364] Clause 11. A light modulator according to any one of clauses 8 to 10, wherein the pattern coating is disposed on at least a portion of the electrode and optionally disposed on an inner side of one of the first and second substrates but not on the opposing substrate.

[0365] Item 12. An optical modulator according to any one of Items 8 to 11, wherein the coating is arranged in a random pattern on the inner side of at least one of the first substrate and the second substrate, so that at least a portion of the multiple electrodes applied to the inner side and / or the inner side of the substrate where no electrodes are provided is provided with the coating, and so that at least a portion of the multiple electrodes applied to the inner side and the inner side of the substrate where no electrodes are provided are not provided with the coating.

[0366] Clause 13. The light modulator of any of the preceding clauses, wherein the protective coating is a transparent coating or a translucent coating.

[0367] Clause 14. The light modulator of any preceding clause, wherein the protective coating is a reflective coating.

[0368] Clause 15. The light modulator of any preceding clause, wherein the protective coating provides additional optical functionality to the modulator.

[0369] Clause 16. A light modulator according to any of the preceding clauses, wherein the protective coating has a thickness in the range of 1 nm to 100 μm, preferably in the range of 10 nm to 50 μm, preferably in the range of 100 nm to 10 μm.

[0370] Clause 17. A light modulator according to any one of the preceding clauses, wherein:

[0371] - at least one of the first substrate and the second substrate is applied with at least three electrodes, or

[0372] - Both the first substrate and the second substrate are applied with at least three electrodes.

[0373] Clause 18. A light modulator according to any of the preceding clauses, wherein a distance between subsequent main lines of the plurality of electrodes in the first substrate is greater than a distance between subsequent main lines of the plurality of electrodes in the second substrate.

[0374] Clause 19. A light modulator according to any of the preceding clauses, having a transparent state and a non-transparent state, or having a reflective state and a non-reflective state, the light modulator being configured to:

[0375] - switching to a non-transparent state or to a non-reflective state by creating an alternating voltage on at least one of the first and second substrates, applying an alternating current between at least the first and second electrodes on the first substrate and / or between the first and second electrodes on the second substrate;

[0376] - switching to a transparent state or switching to a reflective state by creating an alternating voltage between the first substrate and the second substrate, applying an alternating current between a first electrode on the first substrate and a first electrode on the second substrate and / or between a second electrode on the first substrate and a second electrode on the second substrate.

[0377] Clause 20. An optical modulator according to any of the preceding clauses, wherein at least one of the plurality of electrodes of each substrate comprises at least a first electrode and a second electrode, each of the first electrode and the second electrode comprising:

[0378] - a plurality of main lines extending across the substrate in a first direction, wherein the plurality of main lines of the first electrode and the second electrode are arranged alternately on the substrate;

[0379] - A plurality of branch lines extending from the main line into the region between the main lines, wherein the branch lines extending into the region between the first main line and the second main line of the first electrode and the second electrode extend alternately from the first main line and the second main line, and at least one of two subsequent branch lines extending into the same region extends across at least half of the region in a second direction orthogonal to the first direction.

[0380] Clause 21. The light modulator of clause 20, wherein when projected in the first direction, two subsequent branch lines extending into the same region between the first main line and the second main line overlap in the second direction.

[0381] Clause 22. An optical modulator according to any of clauses 20 to 21, wherein two subsequent branch lines extending into the same area between the first main line and the second main line have different lengths, the longer branch line being at least 5% longer than the shorter branch line.

[0382] Clause 23. An optical modulator according to any one of clauses 20 to 22, wherein the distance between a main line and a subsequent main line on the substrate of the first electrode and the second electrode varies in the second direction and / or in the first direction.

[0383] Clause 24. An optical modulator according to clause 23, wherein the distance between the main lines has the following configuration:

[0384] - alternate between increasing towards a maximum distance and decreasing towards a minimum distance, and / or

[0385] - Increase or decrease the amount of randomness within the maximum and minimum distances, and / or

[0386] - wherein the sequence of distances between the main lines in the second direction varies randomly along the substrate, wherein the sum of the distances is between a minimum and a maximum total distance.

[0387] Clause 25. An optical modulator according to any one of clauses 20 to 24, wherein a main line and branch lines extending from the main line are constructed as a connected series of sub-main lines extending from the branch lines, the sub-main lines in the series are connected to form the main line, wherein,

[0388] - the branch lines extending from the same side of the sub-main line have equal lengths, and / or

[0389] - the branch lines extending from the same side of the sub-main line are parallel, and / or

[0390] - The number of branch lines extending from either side of the sub-main line is equal.

[0391] Clause 26. An optical modulator according to clause 25, wherein the branch lines extending from the same side of the sub-main line and the branch lines extending from the subsequent sub-main line of the same main line are configured as follows:

[0392] - have different lengths, and / or

[0393] - at a different angle to the first direction, and / or

[0394] -There are different numbers of branch lines extending from one side of the sub-main line.

[0395] Clause 27. The optical modulator according to any one of clauses 25 to 26, wherein an angle between the branch line and the first direction in the sub-main line is randomly selected between 45 degrees and 90 degrees.

[0396] Clause 28. An optical modulator according to any one of clauses 25 to 27, wherein a sub-main line and a subsequently connected sub-main line in the same main line are displaced relative to each other in both the first direction and the second direction.

[0397] Item 29. An optical modulator according to any one of Items 20 to 28, wherein the pattern in which the first electrode and the second electrode are arranged is subdivided into a group of blocks extending across the substrate in the first direction and the second direction, each block including multiple sub-lines that are a portion of the multiple main lines of the first electrode and multiple sub-lines that are a portion of the multiple main lines of the second electrode, wherein at least one block is repeated multiple times on the substrate.

[0398] Clause 30. The light modulator of clause 29, wherein:

[0399] - In some blocks, the sub-main line electrode includes multiple branch lines, and in some blocks, the electrode does not include multiple branch lines, and / or

[0400] - In some blocks, the sub-main lines are straight, and in some blocks, the sub-main lines are wavy.

[0401] Item 31. An optical modulator according to any of the preceding items, wherein the pattern in which the electrodes are arranged is subdivided into multiple parts, in which at least one of the electrode line gap, electrode line thickness, electrode line width, electrode material, electrode line shape and electrode line direction is different, thereby resulting in an optical effect.

[0402] Clause 32. A light modulator according to any of the preceding clauses, wherein a geometry of the electrode is different across at least one of the first substrate and the second substrate, the geometry of the electrode being selected from the group consisting of: thickness, width, shape, area and volume.

[0403] Clause 33. A light modulator according to any of the preceding clauses, wherein a primary electrode is at least partially connected to a further secondary electrode parallel to the primary electrode, wherein:

[0404] - the secondary electrode is connected to the primary electrode via a semiconductor layer, the secondary electrode is electrically connected to the primary electrode line via the semiconductor layer, the semiconductor layer allows current to flow on the primary electrode only above a threshold voltage, and / or

[0405] - the secondary electrode is transparent, and / or

[0406] - the secondary electrode comprises a capacitor arranged to locally hold an electric charge, and / or

[0407] - The secondary electrode comprises a photovoltaic semiconductor material, the secondary electrode providing power to the primary electrode circuit.

[0408] Clause 34. A light modulator according to any of the preceding clauses, wherein a plurality of electrodes extend across the substrate in two dimensions, and at least a first electrode of the plurality of electrodes is separated from at least a second electrode of the plurality of electrodes in a third dimension.

[0409] Clause 35. A light modulator according to any of the preceding clauses, wherein electrodes on a first substrate are at least partially arranged in the same pattern as second electrodes on a second substrate, wherein the patterns of the first and second electrodes are shifted relative to each other.

[0410] Clause 36. A light modulator method comprising:

[0411] An optical modulator is provided, comprising:

[0412] - a first substrate and a second substrate, the inner sides of the first substrate and the second substrate being arranged opposite to each other,

[0413] - a plurality of electrodes (110, 120) are applied to the inner side of each of the first and second substrates, the plurality of electrodes having a surface area facing the opposing substrate,

[0414] - wherein each of the plurality of electrodes is arranged in a pattern spanning the substrate, each of the plurality of electrodes comprises a plurality of main lines extending across the substrate in a first direction, the plurality of main lines of the plurality of electrodes being arranged alternately with each other on the substrate, and

[0415] - wherein at least a portion of the surface area of ​​the plurality of electrodes is provided with a protective coating;

[0416] - an optical layer between the first and second substrates, the optical layer comprising a fluid comprising particles, wherein the particles are charged or chargeable;

[0417] selecting an alternating current or voltage of one of a plurality of maximum amplitudes corresponding to one of a plurality of transparency levels or reflectivity levels of the light modulator;

[0418] The alternating current is applied to the electrodes to obtain an electromagnetic field between the electrodes, thereby providing electrophoretic movement of the particles towards or away from the electrodes, resulting in modulation of the optical properties of the light modulator.

[0419] Clause 37. A transitory or non-transitory computer-readable medium comprising data representing instructions which, when executed by a processor system, cause the processor system to perform the method according to clause 36.

[0420] It should be noted that the above-mentioned embodiments illustrate rather than limit the disclosed subject matter, and that those skilled in the art will be able to design many alternative embodiments.

[0421] In the claims, any reference numerals placed in brackets shall not be interpreted as limiting the claims. The use of the verb "comprise" and its variants does not exclude the presence of elements or steps other than those stated in the claims. The article "a" or "an" in front of an element does not exclude the presence of multiple such elements. When an expression such as "at least one" is placed before a list of elements, it means selecting all elements or any subset thereof from the list. For example, the expression "at least one of A, B, and C" should be understood to include only A, only B, only C, both A and B, both A and C, both B and C, or all of A, B, and C. The subject matter of the present disclosure can be implemented by hardware including several different elements, and by a suitably programmed computer. In a device claim that lists several parts, several of these parts can be implemented by the same hardware item. The mere fact that certain measures are recorded in mutually different dependent claims does not indicate that the combination of these measures cannot be used to exert advantages.

[0422] In the claims, the signs in parentheses refer to the reference signs in the drawings of the exemplary embodiments or the formula of the embodiments, thereby improving the intelligibility of the claims. These signs should not be interpreted as limiting the claims.

Claims

1. An optical modulator, comprising: - a first substrate and a second substrate, the inner sides of the first substrate and the second substrate being arranged opposite to each other, - a plurality of electrodes are applied to the inner side of each of the first and second substrates, each of the first and second substrates having an inner surface area, - wherein each of the plurality of electrodes is arranged in a pattern spanning the substrate, each of the plurality of electrodes comprises a plurality of main lines extending across the substrate in a first direction, and the plurality of main lines of the plurality of electrodes are alternately arranged on the substrate, and - wherein at least a portion of the inner surface area of ​​at least one of the first substrate and the second substrate is provided with a protective coating to prevent short circuits between electrodes of the plurality of electrodes; - an optical layer between the first and second substrates, the optical layer comprising a fluid comprising particles, wherein the particles are charged or chargeable; - a controller configured to apply an electric potential to the plurality of electrodes so as to obtain an electromagnetic field between the plurality of electrodes, thereby providing the particles with electrophoretic motion towards or away from one of the plurality of electrodes, resulting in modulation of the optical properties of the light modulator.

2. The optical modulator of claim 1 , wherein the short circuit between electrodes of the plurality of electrodes is caused by direct contact of at least one of the electrodes with one or more of particles, fibers, stones, lumps and granules in the fluid.

3. The light modulator of claim 2, wherein one or more of particles, fibers, stones, lumps, and granules in the fluid are generated by aggregation of electrophoretic particles in the fluid.

4. The light modulator of claim 3, wherein the aggregation comprises a high conductivity aggregation and / or the aggregation is generated by an electrophoretic operation of the light modulator.

5. An optical modulator according to any one of the preceding claims, wherein the short circuit comprises - a short circuit between an electrode on the first substrate and an electrode on the second substrate, wherein the electrodes are arranged opposite to each other; and / or - a short circuit between electrodes on the first substrate, the electrodes being arranged adjacent to each other; and / or - a short circuit between electrodes on the second substrate, said electrodes being arranged adjacent to each other.

6. The light modulator of claim 1, wherein the protective coating is at least partially electrically non-conductive and / or electrically insulating.

7. The light modulator of claim 1, wherein the protective coating forms an electrically insulating layer between at least a portion of electrodes in the plurality of electrodes.

8. The optical modulator of claim 1, wherein the resistivity of the protective coating is at least 10 7 Ω·m, or at least 10 9 Ω·m, or at least 10 10 Ω·m, or at least 10 11 Ω·m.

9. The light modulator of claim 1, wherein the protective coating is a continuous, preferably uniform coating.

10. The light modulator of claim 1, wherein the protective coating is disposed on at least a portion of an inner surface area of ​​one of the first and second substrates, wherein an inner surface of the opposing substrate is not provided with a protective coating.

Images