Improved optical modulator

Abstract

The invention relates to an optical electrophoretic modulator for switching and reverse switching between a transparent state and an opaque state and to the use thereof, in particular as a shade. The electrophoretic apparatus includes fluids and particles, electrodes for moving the particles, and various other elements.

Description

Technical Field

[0001] The present invention relates to an electrophoresis device for switching between a transparent mode and a non-transparent mode and a use thereof, in particular as a blackout curtain. The electrophoresis device comprises a fluid and particles, electrodes for moving the particles, and various other elements. Background Art

[0002] Typically, electronic display devices, especially electrophoretic display devices, are pixelated display devices in which charged pigment particles move vertically to produce the desired pixel coloring. In its first method, black particles and white particles are encapsulated, defining a closed space in which black particles move upwards at the same time as white particles move downwards, or vice versa; therefore, white particles or black particles are visible and hide the other type at the same time; a transparent state is not possible. Pigment particles are not free to move because they are encapsulated in microcapsules. The pigment particles are relatively large, typically larger than 500nm (0.5μm), and 1μm or larger on average. The two electrodes commonly used are located one above the other. Switching is achieved by an electric field, and the particles are typically charged or chargeable; this type of display device is generally referred to as E-ink, such as described in US2002 / 167500Al. The microcapsules, typically made of plastic, are relatively small (30μm). Colors can be provided by applying color filters. Colored particles are being developed and can be driven electrically accordingly. Switching is relatively fast (under 300 milliseconds), stability is good (over 10 seconds), and contrast is also good. Stacks of layers cannot be formed, ie always provide "color", due to the inherent presence of microcapsules in either the black or white state.

[0003] In alternative technologies, the colored particles can move more freely throughout the pixel, essentially independently of each other. The colored particles move from one position in the pixel to another, which is usually also due to the applied electric field. The first position is usually where the particles gather, with a high density or concentration, while the second position is usually where the particles are evenly spread, with a lower concentration or density, thereby providing a colored effect. The area of ​​the first position (commonly referred to as the accumulation area) is relatively small. Switching is achieved by moving the particles from the accumulation electrode to the second field electrode. By gathering particles to the accumulation area, the transparency of the display is changed. In the top view, the field area and the accumulation area are adjacent to each other, contrary to the E-ink method. For further details of the current developments in the field and the shortcomings of this technology, refer to the recently submitted NL2010936, which is incorporated herein by explicit reference. Compared with other technologies, the main difference is that the colored particles are always visible. Some details are provided below. The advantage of the lateral switching of charged particles is that the electrophoretic display device can include a completely transparent state. In principle, a reflector or possibly a backlight can be selected. However, in electrophoretic displays, the control of the electric field and the distribution of particle motion is not precise enough to provide uniform pixel absorption in the "dark" state and to fix the particles in the "light" state to the electrodes. Switching from the first state to the second state in such displays can also be relatively slow; typically, too slow for most applications, even with recently improved equipment. It should be noted that typically prior art particles move at speeds of less than about 0.1 mm per second, which is considered too slow for some applications, at least ten times slower. For full color displays, which may include stacks of such pixels, the situation is significantly worse.

[0004] Note that there are various pixel layouts. A problem with electrophoretic displays is the lifetime, especially for the electrodes. It has been found to be difficult to obtain a stable configuration of, for example, pixels, especially in view of the electric fields provided. In addition, it remains difficult to obtain good switching times and stability.

[0005] In general it should be noted that electrophoretic pixels are relatively difficult to model. Simple calculations, such as the coupling of fluid viscosity and applied fields, do not work well in practice. This is reflected in the fact that large companies have tried and failed to develop electrophoretic pixels for many years.

[0006] The object of the present invention is to overcome the disadvantages of prior art electronic devices without compromising the functions and advantages. Summary of the invention

[0007] The first aspect of the present invention relates to an optical modulator according to claim 1, the second aspect relates to a product comprising the optical modulator, and the third aspect relates to a method for operating the optical modulator. The present invention provides very different operating modes in different situations, wherein a pulse mode is used to apply an electric field and a good conductive material is used as an electrode. The optical modulator is used for switching between a transparent state and an at least partially non-transparent state and reverse switching, wherein in the non-transparent state, more than 70% of the light, such as more than 90% of the light is blocked from passing through the modulator, and wherein in the transparent state, most of the light is allowed to pass through. In the non-transparent state, people can still see the image on the other side of the optical modulator. The optical modulator comprises a first substrate and a second substrate (11, 12), wherein the substrates are optically transparent, typically more than 95% transparent at relevant wavelengths, such as more than 99% transparent. At least two electrodes 13, 14 are arranged on the inner side of the substrates. These electrodes are used to drive particles. A fluid 15 is arranged between the substrates, and the fluid comprises nanoparticles and / or microparticles, wherein the particles are charged and can be driven by the electric field to move towards or away from the electrodes according to the applied potential. The particles are adapted to absorb light and thereby prevent the passage of certain wavelengths. In addition, a connector is provided for applying an electromagnetic field to the electrodes, wherein the electromagnetic field applied to the electrodes provides for the movement of the nanoparticles and micron particles from the first electrode to the second electrode and vice versa, and the optical modulator is characterized in that the electrodes comprise a conductive material having a resistivity of less than 100 nΩm (at 273K, as a comparison, the commonly used ITO has a resistivity of 10 5 nOm), which is similar to that at 20°C greater than 1*10 7The electrical conductivity of S / m. As a further feature, the resistivity per unit area (ohm per square, Ω / □) can also be used; then, it can be optionally less than 80Ω / □ (at 273K), preferably less than 60Ω / □, more preferably 10Ω / □, such as less than 2Ω / □. For this purpose, a good conductive material is used. A further feature is that at least two electrodes are suitable for providing electric power between the electrodes, that is, the particles move in a substantially horizontal direction parallel to the substrate. A further feature is a power supply electrically connected to at least two electrodes, wherein the power supply is suitable for providing waveform electricity, wherein at least one of the amplitude, frequency and phase is applicable, and wherein the electrode is in contact with the fluid fluid, the contact can be direct (the fluid contacts the electrode) or indirect (the fluid contacts the electrode through a second medium such as through a porous layer), and wherein the electrode covers 1% to 30% of the surface of the substrate. Surprisingly, a stable electrode is obtained by this configuration, that is, the electrode can remain operational for a long time without any degradation. Switching is acceptable and can be improved in specific applications. The stability of the two states (transparent and non-transparent) is good. Typically, the modulator comprises colored particles that are capable of moving from a first position (e.g., a storage area) to a second position. In addition, the particles are charged or chargeable. Moreover, the particles may be relatively small, for example, less than 900nm, preferably less than 400nm, and greater than 30nm, preferably greater than 40nm, such as 60nm to 200nm. For improved movement and control, smaller particles are preferred. For applying movement, at least two electrodes are provided. For the present invention, it was found that two electrodes are sufficient for each substrate. The electrode occupies an area on the inside of the substrate, i.e., facing the fluid. One electrode may be an electrically neutral (or grounded) electrode. For controlling the movement of the colored particles and the stability of the state (transparent or colored) in the device, a driver circuit for applying an electromagnetic field to the modulator may be provided.

[0008] The present modulator is characterized in that the electrodes include a conductive material having a resistivity of less than 100 nOhm (at 273K), at least two electrodes are suitable for providing power between the electrodes parallel to the substrate when switching to a non-transparent state, and at least two electrodes are suitable for providing power between the electrodes in a direction relative to the substrate when switching to a transparent state, wherein the direction is selected from: parallel to the substrate, perpendicular to the substrate, inclined relative to the substrate, and their combination, and includes a power supply, electrically connected to the at least two electrodes, wherein the power supply is suitable for providing waveform electricity, wherein at least one of amplitude, frequency and phase is applicable, and wherein the electrodes are in contact with the fluid, and wherein the electrodes cover 1% to 70% of the surface of the substrate. This provides movement of particles. Moreover, the present modulator can be safely operated in the presence or absence of electrical corrosion. Typically, the distance between the first substrate and the second substrate of the present modulator is less than 30μm, such as 15μm. The present modulator may include one or more pixels, typically a plurality of pixels, which are single optically switchable entities whose size can vary. The substrate at least partially encloses a volume, which can be a pixel. Typically, this distance can be significantly smaller than existing devices. The present design allows lateral movement, better control of particle movement together with a relatively small distance, good control of the electric field that is almost insensitive to defects in the used materials such as disturbances, no production problems when delineating the substrate contour, and high stability of the two states. In addition, the design is more robust, such as the electrodes remain substantially intact after a longer period of time. Moreover, good optical performance is provided. Even, in contrast to existing devices, the present design allows stacking, such as described in detail below.

[0009] For moving particles around, an appropriate electric field is applied to the electrodes, for example to attract or repel charged particles. This is done for each electrode that has the desired effect; other parts can have no electric field. In this way, each individual part (usually a pixel) can have an independent address, so each individual part can be in transparent (only particles on electrode 16 are visible) or colored mode. Similarly, the electrode as a whole can be at zero (0) voltage, or at a positive or negative voltage to contribute to the electric field. Similarly, the electric field can be updated from time to time.

[0010] The term "optical" may relate to wavelengths visible to the naked eye (about 380nm to about 750nm) where applicable, and to a wider range of wavelengths where applicable, including infrared (about 750nm to 1μm), ultraviolet (about 10nm to 380nm) and their sorting. Importantly, the present pixels and devices are fully adaptable, for example to changing light conditions. The present device may include pixels therein that can change, i.e. within seconds. Typically, one type of colored particles may be present in the present modulator, such as selected from red, green, blue, or selected from magenta, cyan and yellow, and their combinations. The modulator can change from white (transparent) to one of the above colors and vice versa depending on the change of the electric field. In addition, black particles may be present, but this is not necessary as it will complicate the design to a certain extent. Typically, for black / transparent applications, only black particles are present.

[0011] For full color applications, a stack of two or three modulators can provide most or all colors, respectively. With at least some other arrangements, such a stack is considered impossible because in this case either the black particles or the white particles will always be visible; and further, it is generally not possible to provide considered features such as brightness, contrast, hot / cold effects, complementary contrast, simultaneous contrast, saturation, and intensity. For the present pixel, all of these features can be very accurately adapted and controlled.

[0012] It was found that the present modulator comprising only black particles has a high black contrast ratio.

[0013] The device may comprise a driver circuit for changing the appearance of (single) pixels by applying an electromagnetic field. Thus, the appearance of the display device or one or more components thereof may also be changed.

[0014] The electronic device may include a unique code for identification. Thus, each electronic device may be individually identified.

[0015] The present device including substrate, protective layer etc. can be relatively thin and can therefore in principle be applied to, for example, a stack of devices. The present display device has a thickness of less than 0.1 cm, preferably a thickness between 10 μm and 500 μm, more preferably a thickness between 15 μm and 300 μm, even more preferably a thickness between 25 μm and 200 μm, such as 50 μm to 100 μm. The thickness can vary, for example, depending on the number of devices employed. Therefore, the present display device (in transparent mode) is invisible or difficult to see with the naked eye.

[0016] Especially for smaller devices, a power supply may be provided, typically a battery.

[0017] The present invention is based in part on earlier developments of IRX Technologies BV. For this purpose and in order to better understand the underlying technology, reference is made to the recently filed (June 7, 2013) Netherlands patent application NL2010936. The various aspects, examples, advantages, etc. apply in principle one-to-one to the present invention. It should be noted that the technology disclosed in the above patent application has not yet been put into practice. Various obstacles have been encountered that still need to be solved. For example, bistability and insufficient switching time. In principle, various other aspects, examples, advantages, etc. apply one-to-one to the present invention. The teachings and examples of the above document are incorporated herein by reference. The present invention also provides an improved layout according to the prior art.

[0018] Accordingly, the present invention provides a solution to one or more of the above problems.

[0019] The advantages of the present specification are described in detail throughout the specification. DETAILED DESCRIPTION

[0020] A first aspect of the invention relates to an optical modulator according to claim 1 .

[0021] In an exemplary embodiment of the optical modulator, the waveform power can be characterized by a frequency between 0.01 Hz and 100 Hz and an amplitude variation of 5% to 100% of the maximum amplitude, where the maximum amplitude is the maximum voltage operation, and by a phase variation (phase shift) between 0° and 180°. Based on the ink characteristics, it was found that low frequency waveforms (between 0.01 Hz and 1 Hz) increased the transparency of the optical modulator. It was found that high frequency waveforms (between 70 Hz and 100 Hz) maintained or reduced the transparency of the optical modulator. It was found that low waveform amplitudes (between 20% and 50%) maintained low transparency levels. It was found that high waveform amplitudes (between 80% and 100%) maintained high transparency levels.

[0022] In an exemplary embodiment of the optical modulator, at least two electrodes form an interdigitated pattern, preferably on two substrates. The fingers of the interdigitated pattern may also include at least one branch, typically at least one branch on each side thereof, such as branches spaced between 0.01 cm and 3 cm apart.

[0023] In an exemplary embodiment of the optical modulator, the interdigitated pattern is a regular two-dimensional pattern, wherein each finger comprises at least one waveform, wherein the waveform has an amplitude A and a width W, and wherein the fingers are at a distance d from each other, i.e. wherein the fingers are separated from each other. It has been found that due to the presence of the electrodes on the substrate, higher order images are formed. In order to minimize these secondary images, the fingers of the interdigitated electrodes are preferably non-linear (see also the Examples).

[0024] In an exemplary embodiment of the optical modulator, the symmetry of the waveform sinusoidal shape is broken, such as wherein a concave first protrusion is provided at the highest point of the waveform shape, and wherein a concave or concave second protrusion is provided at the lowest point of the waveform shape. In this way, higher order images are significantly reduced. Compared with a straight line pattern, the brightness is reduced from about 180 to 60 (in 8-bit grayscale).

[0025] In an exemplary embodiment of the optical modulator, the first protrusions have a width that is greater than the width of the second protrusions. It has been found that even higher order images are reduced thereby.

[0026] In an exemplary embodiment of the optical modulator, the width W of the waveform is 50 μm to 750 μm, such as 100 μm to 500 μm.

[0027] In an exemplary embodiment of the optical modulator, the amplitude A of the waveform is 10 μm to 500 μm, such as 20 μm to 400 μm.

[0028] In an exemplary embodiment of the optical modulator, the distance d between the fingers is 10 μm to 500 μm, preferably 10 μm to 100 μm, such as 20 μm to 70 μm.

[0029] In an exemplary embodiment of the optical modulator, the width of the first protrusion is 10 μm to 50 μm, such as 20 μm to 30 μm.

[0030] In an exemplary embodiment of the optical modulator, the width of the second protrusion is 10 μm to 50 μm, such as 20 μm to 30 μm.

[0031] In an exemplary embodiment of the optical modulator, the width of the first protrusion is 2 to 4 times the width of the second protrusion.

[0032] In an exemplary embodiment of the optical modulator, a height h of the first protrusions is 5 μm to 20 μm, such as 10 μm to 15 μm.

[0033] In an exemplary embodiment of the optical modulator, the height h of the second protrusions is 5 μm to 20 μm, such as 10 μm to 15 μm.

[0034] In an exemplary embodiment of the optical modulator, the protrusion is in the form of a portion of a circle or an ellipse.

[0035] In an exemplary embodiment of the optical modulator, the transition from the waveform to the convexity or vice versa is gradual.

[0036] In an exemplary embodiment of the optical modulator, the power supply is adapted to provide pulses and avoid providing pulses during intervals, such as pulses between 0.1 sec / min and 10 sec / min, and intervals between 0.1 seconds and 1000 seconds, preferably between 5 seconds and 600 seconds.

[0037] In an exemplary embodiment, the optical modulator may include a controller, wherein the controller is adapted to maintain an AC voltage having a positive voltage magnitude of 0.9 to 1.1 times the magnitude of the negative voltage, preferably 0.95 to 1.05 times its magnitude, more preferably 0.99 to 1.01 times its magnitude, such as 0.995 to 1.005 times its magnitude, and is adapted to change the potential according to the current.

[0038] In an exemplary embodiment, the optical modulator may include at least two alignment marks on each substrate for aligning the substrates, preferably so that the electrodes of the first substrate are completely aligned with the electrodes of the second substrate, and more preferably the electrodes of the first substrate are projected onto the electrodes of the second substrate.

[0039] In an exemplary embodiment of the optical modulator, the electrode comprises copper, silver, gold, aluminum, graphene, titanium, indium, and combinations thereof, preferably copper.

[0040] In an exemplary embodiment of the optical modulator, the power supply is operated at an AC frequency for switching to the transparent state between 10 Hz and 100 Hz.

[0041] In one exemplary embodiment of the optical modulator, the power supply is operated at an AC frequency for switching to the non-transparent state at less than 1 Hz, such as 30 mHz to 500 mHz, typically in the case of slow moving particles.

[0042] In an exemplary embodiment of the optical modulator, in one switching cycle, the power supply is operated at an AC frequency for switching to the transparent state of 10 Hz to 100 Hz, in combination with operating the power supply at a positive voltage or a negative voltage in the initial stage of the cycle when switching to the transparent state, and operating the power supply at a negative voltage or a positive voltage in the final stage of the cycle when switching to the non-transparent state. Between the initial stage and the final stage, there is no DC positive voltage or DC negative voltage. Thus, good control, good stability and low power consumption are also achieved.

[0043] In an exemplary embodiment of the optical modulator, the fluid includes counter ions for compensating the charge on the particles.

[0044] In an exemplary embodiment, the optical modulator may include a temperature sensor and / or a controller, wherein the temperature sensor is electrically contacted to the controller, wherein the controller is in contact with the power supply, and wherein the controller is adapted to compensate the output of the power supply based on a temperature measured by the temperature sensor.

[0045] In an exemplary embodiment, the optical modulator may comprise a stack of optical modulators, wherein the number of optical modulators is between 2 and 10, preferably between 3 and 5. Each modulator in the stack may comprise different colored particles and (different) mixtures thereof. Thus, a full-color device may be provided. In one embodiment thereof, the first substrate of the second modulator is identical to the second substrate of the first modulator, i.e. combined into one substrate. This is a major advantage of the device, thereby reducing the number of substrates in the stack, improving contrast and transparency, and reducing complexity. In one embodiment, the fluid is transparent. The above embodiments may be combined in whole or in part.

[0046] In an exemplary embodiment of the optical modulator, optionally at least one substrate 11 , 12 of the first optical modulator and at least one substrate 11 , 12 of the second optical modulator are identical.

[0047] In an exemplary embodiment of the optical modulator, each electrode has a width of between 1 μm and 30 μm, preferably between 3 μm and 10 μm, such as 5 μm to 8 μm.

[0048] In an exemplary embodiment of the optical modulator, each electrode has a width of between 0.1 μm and 200 μm, preferably between 1 μm and 25 μm, more preferably between 1.5 μm and 15 μm, such as 2 μm to 5 μm.

[0049] In an exemplary embodiment of the optical modulator, the electrodes comprise a conductive material having a resistivity of less than 30 nOhm (at 273 K), preferably less than 20 nOhm.

[0050] In an exemplary embodiment of the optical modulator, a spacer is provided between the first substrate and the second substrate, preferably 1 spacer / mm 2 Up to 10000 pieces / mm 2 , such as 5 pieces / mm 2 Up to 100 pieces / mm 2. In one embodiment, the first substrate and the second substrate are spaced apart by (glass) beads having a diameter between 2 μm and 30 μm, preferably between 14 μm and 16 μm, such as 15 μm. The randomly distributed beads, preferably glass beads or polymer beads, define the distance between the substrates very accurately, provide strength and flexibility, and hardly disturb the movement of the colored particles. The beads can be produced to obtain a very uniform distribution of their sizes, for example with an accuracy of more than 0.1 μm. The average volume of the beads is 0.1 vol.% to 15 vol.% relative to the total volume, i.e. they only occupy a small volume. The beads can be colored or black.

[0051] In an exemplary embodiment of the optical modulator, the electrode covers 2% to 30%, preferably 3% to 20%, more preferably 4% to 10%, such as 5% to 8% of the substrate surface. In an exemplary embodiment of the optical modulator, the counter ion is selected from sulfate, chloride, bromide and combinations thereof.

[0052] In an exemplary embodiment of the optical modulator, the potential is between -60V and +60V, preferably between -20V and +20V, more preferably between -15V and +15V. It should be noted that the electric field (V / μm) is higher than that of existing devices, typically 5 to 20 times higher, depending on the small distance between the first substrate and the second substrate. It has been found that the fluid performs better at higher voltages, for example in terms of flow and switching time. It is preferred to stabilize the particle charge. Therefore, the performance is better, for example, faster and better controllable switching times are achieved according to the distribution on the electrodes in the art.

[0053] 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.

[0054] In an exemplary embodiment of the optical modulator, the substrate material is selected from glass and polymer.

[0055] In an exemplary embodiment of the optical modulator, the nanoparticles / microparticles may include a coating on a pigment and preferably a core.

[0056] In an exemplary embodiment of the optical modulator, the substrates (11, 12) are aligned and / or the electrodes (13, 14) are aligned.

[0057] In an exemplary embodiment of the optical modulator, the fluid is a non-polar fluid with a dielectric constant less than 15, such as a branched or unbranched C8-C 60 Alkanes, branched or unbranched C8-C 60Olefins, branched or unbranched C6-C60 alcohols, branched or unbranched C6-C 60 Alkenols, branched or unbranched C8-C 60 Ketones, branched or unbranched C8-C 60 Aldehydes, silicone oils, and combinations thereof. In the case of more alkanes, alkenes, alcohols, enols, ketones, and aldehydes, branched molecules are preferred. An example is squalane (C 30 H 62 ) and squalene (C 30 H 60 ).

[0058] In an exemplary embodiment of the optical modulator, the size of the nanoparticles is between 20nm and 1000nm, preferably between 20nm and 300nm, and more preferably less than 200nm. The particle diameter is defined herein as the maximum distance that can be formed between two relatively parallel lines tangent to its boundaries. It has been found that these particles provide a good distribution of particles on the present (field) electrode. Depending on the electromagnetic field to be applied, the present particles are chargeable or charged. Similarly, magnetic particles can be used. It is preferred to provide a stable dispersion; therefore the above sizes are preferred. The particle size is considered to be a measure of its average diameter. The particle size distribution can be determined using light scattering, such as using a Malvern Zetasizer Nano Range. It has also been found that smaller particles are significantly attributed to the current characteristics of the pixel.

[0059] In general, the reflectivity of the present modulator is high, typically reflecting more than 50%. Thus, transmittances of more than 65% are achieved for black particles, and values ​​of 71% or more are achieved for refined modulators. Transmittances of more than 80% for colored particles (such as CMY) are easily achievable, however levels of more than 85% or even more than 90% have been achieved. This is very relevant, especially in light of stacked modulators.

[0060] In one embodiment, the open (non-electrode) area is more than 70%, such as 80% transparent, preferably more than 90%; the transparency is typically determined at a wavelength of 550nm. The open area can be made of a substrate, such as glass and a suitable polymer, such as polycarbonate (Perspex) and PET. The material may have a thickness between 0.01mm and 2mm, preferably between 0.025mm and 1mm, such as 0.05mm to 0.5mm. If flexible pixels and / or displays are required, it is preferred to use a thin material. If a certain strength is required, a thicker material is preferred. It has been found that at this transparency, energy consumption can be reduced even further. The material provides great advantages in terms of use, reduced load device requirements, reduced charge storage devices, etc. In particular, the material is more suitable for use when the power grid is not available.

[0061] In one embodiment, the modulator may be made of a flexible polymer and the rest of the device may be made of glass. The glass may be rigid glass or flexible glass. A protective layer may be provided if desired. If more than one color is provided, more than one flexible polymer layer may be provided. The polymer may be polyethylene naphthalate (PEN), polyethylene terephthalate (PET) (optionally with a SiN layer), polyethylene (PE), etc. In another embodiment, the device may be made of at least one flexible polymer. Thus, the modulator may be adhered to any surface, such as by using an adhesive.

[0062] In an exemplary embodiment of the optical modulator, the particles are suitable for absorbing light with a wavelength between 10nm and 1mm, such as 400nm to 800nm, 700nm to 1μm and 10nm to 400nm, and / or a portion of light (filter) whose wavelength range falls within 10nm to 1mm, and combinations thereof.

[0063] In an exemplary embodiment of the optical modulator, the distance between the first substrate and the second substrate is less than 500 μm, preferably less than 200 μm, preferably less than 100 μm, even more preferably less than 50 μm, such as less than 30 μm.

[0064] In an exemplary embodiment of the optical modulator, electrodes are used to store particles.

[0065] In an exemplary embodiment of the optical modulator, the charge on the particles is 0.1e to 10e (5*10 -7 -0.1C / m 2 ).

[0066] In an exemplary embodiment of the optical modulator, the coating of the particles is made of a material selected from the group consisting of: a conductive material and a semiconductive material.

[0067] In an exemplary embodiment of the optical modulator, the fluid is at 1 g / m 2 Up to 1000g / m 2 The amount is present, preferably 2g / m 2 Up to 75g / m 2 , more preferably 20g / m 2 Up to 50g / m 2 , such as 30g / m 2 Up to 40g / m 2 A big advantage is that less fluid and particles can be used with this layout.

[0068] In an exemplary embodiment of the optical modulator, the particles are 0.01 g / m 2 Up to 70g / m 2The amount is present, preferably 0.02g / m 2 Up to 10g / m 2 , such as 0.1g / m 2 Up to 3g / m 2 .

[0069] In an exemplary embodiment of the optical modulator, the particles have a color selected from the group consisting of cyan, magenta and yellow, black and white, and combinations thereof.

[0070] In an exemplary embodiment of the optical modulator, the fluid includes one or more of a surfactant, an emulsifier, a polar compound, and a compound capable of forming a hydrogen bond.

[0071] In an exemplary embodiment of the optical modulator, the fluid has a relative permittivity εr of less than 100, preferably less than 10, such as less than 5.

[0072] In an exemplary embodiment of the optical modulator, the dynamic viscosity is less than 0.5 Pa.s, preferably less than 100 mPa.s, such as 0.2 mPa.s to 10 mPa.s, for example 0.5 mPa.s to 5 mPa.s, for example 1 mPa.s to 2 mPa.s, preferably the dynamic viscosity is less than 1 mPa.s.

[0073] In an exemplary embodiment of the optical modulator, the optical modulator comprises 10 -8 -50 pixels / mm 2 , preferably 10 -6 -16 pixels / mm 2 , more preferably 5*10 -4 -1 pixel / mm 2 , even more preferably 1*10 -3 -0.11 pixels / mm 2 .

[0074] In an exemplary embodiment of the optical modulator, the controller is adapted to switch individual pixels. In an exemplary embodiment of the optical modulator, the power supply is a combined AC / DC power supply.

[0075] In an exemplary embodiment, the optical modulator may include a driver circuit adapted to provide a time-varying electromagnetic field.

[0076] In an exemplary embodiment of the optical modulator, the waveform power is characterized by a frequency between 0.01 Hz and 100 Hz and an amplitude variation of 5% to 100% of the maximum amplitude, where the maximum amplitude is the maximum voltage operation, and is characterized by a phase variation (phase shift) between 0° and 180°.

[0077] A second aspect of the invention relates to a product comprising an optical modulator according to the invention, wherein the product is selected from the group consisting of a blind, a signage system, an outdoor display, an electronic label, a secondary screen, smart glass, a palette and a screen.

[0078] A third aspect of the invention relates to a method of operating the present optical modulator, the method comprising applying an electric field to move particles from an electrode to a fluid, applying a reverse electric field to move nanoparticles and / or microparticles to diffuse outward to the electrode, using an alternating current having a potential between -220V and +220V and a current between -100μA and +100μA, wherein the electron consumption between the two phases is substantially the same, thereby balancing the positive and negative currents, wherein during the first phase, the electrode material partially dissolves in the fluid, and wherein during the first phase offset by +180 degrees, the dissolved electrode material is redeposited at the electrode. This is generally not the case with prior art devices, where for example only the potential is controlled and balanced, but no attention is paid to balance.

[0079] In an exemplary embodiment of the method, the dissolving electrode is deposited at a reversely charged electrode so that material can be deposited at another electrode than the electrode to which the material was originally provided.

[0080] The present invention is further described in detail by the accompanying drawings and examples, which are exemplary and illustrative and do not limit the scope of the present invention. It is obvious that many obvious or non-obvious variations that can be thought of by those skilled in the art fall within the scope of protection defined by the claims.

[0081] Although described in a detailed illustrative context, the invention is best understood by referring to the accompanying examples and drawings.

[0082] Figure content

[0083] Figure 1a to Figure 1c A side view of the present optical modulator is shown. Figure 2a to Figure 2e Interdigitated electrodes are shown going from the top substrate to the bottom substrate. Figure 3a to Figure 3c The on and off pulses are shown. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] In the figure:

[0085] 10Optical modulator

[0086] 11First substrate

[0087] 12 Second substrate

[0088] 13. First electrode

[0089] 14 Second electrode

[0090] 15 Fluid

[0091] 21 First Bump

[0092] 22 Second bulge

[0093] 30 nanometers / micrometers

[0094] A Waveform Amplitude

[0095] d Distance between fingers

[0096] WWave width

[0097] Figure 1a A side view of an optical modulator is shown. To switch the device to the "on state" in the first example P1, a potential +V1 is applied to each microwire electrode on the top substrate, while a negative voltage is applied to each microwire electrode on the bottom substrate. In the first example P1, the potential difference causes particles to flow to the vicinity of the microwire electrode of the top substrate, where the particles will be substantially aligned to the top microwire electrode. Between the substrates, copper ions from the top copper microwire electrode dissolve in the ionic liquid of the display or smart window, and the dissolved copper ions progressively flow to the corresponding aligned copper microwire electrodes of the bottom substrate, where the copper ions are progressively deposited on the aligned copper microwire electrodes of the bottom substrate.

[0098] Compared to the first example P1, in the second example P2 of this "on state", the voltage of the top electrode copper microwire is opposite to the voltage of the bottom electrode copper microwire. In the second example P2, the voltage of each microwire electrode of the top substrate is now supplied with a negative potential -V1, while the voltage of the aligned copper microwires of the bottom substrate is supplied with a positive potential. The potential difference will cause particles of the window or display to flow to the vicinity of the copper microwire electrode of the bottom substrate, where the particles will agglomerate and substantially align with the bottom microwire electrode. Between the substrates, copper ions from the bottom copper microwire electrode dissolve in the ionic liquid of the display or smart window, and the dissolved copper ions progressively flow to the corresponding aligned copper microwire electrode of the top substrate, where the copper ions are progressively deposited on the aligned copper microwire electrodes of the top substrate. By continuously switching the polarity of the top electrode copper microwire and the bottom electrode copper microwire, a balanced electrolysis current is obtained. In both instances, the corrosion current between the two substrates is balanced or substantially (greater than 95%) balanced, i.e., when the corrosion rate of the top plate electrode occurs, there is a balanced deposition of copper on the bottom electrode in the first instance P1, and vice versa in the second instance P2. Therefore, particles continuously jump or migrate between the top electrode and the bottom electrode, and when the dynamic electrolysis current between the top electrode and the bottom electrode is constant, the display or smart window is always in the on state, so the net loss of copper electrode microwire material on the top substrate and the bottom substrate does not exist or is negligible.

[0099] The electrodes can be in the form of microwires made of copper embedded in a polymer-based substrate. During device operation, an electrochemical current is generated through the display between the two substrates, accompanied by the dissolution of copper ions at one end and the migration of copper ions to the other end. In order to drive the display, a new electrode configuration is required between the two substrates to achieve a balance between the dissolution of the copper electrode and the deposition of the copper electrode between the two substrates, that is, a balance of the current flowing through the display is required. The challenge is how to maintain the balance of the electrochemical current while switching the display. This can be achieved through a new design of the display electrode configuration.

[0100] To achieve the off state, the top substrate and the bottom substrate are arranged as above in the on state. However, on the top substrate, in Example P3 ( Figure 1b ), the potential applied to the first copper microfilament is +V2, and the next intermediate adjacent microfilament has the opposite potential -V2, etc. Figure 1b This forms an alternating voltage on the same substrate. Similarly, each copper microwire electrode of the bottom substrate has the same potential as the corresponding microwire electrode directly opposite the top substrate, as shown in FIG. Figure 1b As shown. Particles migrate diagonally and laterally between the top and bottom substrates, and diffusion of particles into the display viewing apertures facilitates the display's off opaque state. At the same time, copper ions enter the solution at the top copper microwire electrode on the same substrate, which has a positive potential, and the particles progressively flow toward the bottom copper microwire electrode. The migrated copper ions are then deposited on the microwires, which have a negative potential.

[0101] and Figure 1b In contrast, in Example T4 ( Figure 1c ), the voltage is an AC voltage. The potential of the first copper microwire applied to the top substrate is -V2, and the next intermediate adjacent microwire has the opposite potential +V2, etc. Figure 1c This forms an AC voltage on the same substrate. Similarly, each copper microwire electrode of the bottom substrate has the same potential as the corresponding microwire electrode directly opposite the top substrate, as shown in Figure 2b As shown. At the same time, copper ions enter the solution of the bottom copper microwire electrode with positive potential on the same substrate, and the particles gradually flow to the top copper microwire electrode. The migrated copper ions are then deposited on the microwire with positive potential. By using an interdigitated line configuration combined with a top electrode and a bottom electrode configuration, an AC drive cycle can be achieved, as shown Figure 2a to Figure 2e Floor plan shown.

[0102] By using this AC drive cycle between the top substrate and the bottom substrate, diagonal and lateral electric fields are generated between the two substrates, which in turn cause accidental diffusion of particles, resulting in the off state of the display. The electrocorrosion process occurs dynamically in the off state, as well as the AC drive of the display or smart window. In order to drive the display or smart window, a new electrode configuration is required between the two substrates to achieve a balance between the dissolution of the copper electrode in the display liquid and the deposition of the copper electrode on the two substrates, that is, a balance of the current flowing through the display is required. The challenge is how to switch the display while maintaining the balance of the electrochemical current through the display or smart window. This can be achieved through a new design of the display electrode configuration. This is achieved by Figure 1a The configuration shown achieves that a conductive metal electrode pattern, such as a microwire mesh, disposed on the top substrate is completely or substantially aligned with a conductive metal electrode pattern on the bottom substrate. The conductive metal electrode pattern may be deposited on a glass substrate, or the microwire mesh may be embedded in a plastic substrate.

[0103] according to Figure 2e , as follows is an embodiment of forming this electrode pattern. Each electrode pattern consists of 2 repeated parallel lines. The 2 specific parallel lines are initiated by the same sine curve. The so-called Rhinel design is made of a sine curve with an amplitude of 340μm and a wavelength of 340μm. The Rhine2 project is made of a sine curve with an amplitude of 340μm and a wavelength of 640μm. Typically, the line gap is set to 70μm. Then, for each curve, the peak of the sine curve is detected (with a tolerance of 99.9%). For these coordinates (corresponding to the peaks at angle 0 and angle 180, the 2x coordinates of the lowest peak and the highest peak), the following 4 standards are used: S1, S2, S3 and S4. On the first curve of the 2 curves:

[0104] S1 corresponds to the μm value, to the x-coordinate of the peak recovered,

[0105] S2 corresponds to the μm value added to the x-coordinate of the peak,

[0106] S3 corresponds to the μm value to restore the x-coordinate of the low peak,

[0107] S4 corresponds to the μm value added to the x-coordinate of the low peak.

[0108] The portions of the sinusoids from S1 to S2 and S3 to S4 on the first curve are replaced only by downward-pointing elliptical shapes of the sinusoidal amplitudes. The same approach is used for the second parallel sinusoid. The values ​​of S1, S2, S3, and S4 are reused, but their uses are different, as follows:

[0109] S2 corresponds to the μm value, to the x-coordinate of the peak recovered,

[0110] S3 corresponds to the μm value added to the x-coordinate of the peak,

[0111] S1 corresponds to the μm value to recover the x-coordinate of the low peak,

[0112] S4 corresponds to the μm value to be added to the x-coordinate of the lower peak. This method serves to limit the number of possibilities and provides the possibility to calculate more randomized systems.

[0113] In the figure, the elliptical shape points downward. It is also possible to make the elliptical shape always point into the sine curve. A 1000μm*1000μm pattern line image is formed according to the above rules. The lines are drawn in black on a white background to simulate the open state. The Fast Fourier Transform (FFT) function is applied to each image. Then, the filter is applied to the FFT image. Each pixel value below 180 is set to 0, that is, black. Then, each of the above values ​​in 8-bit grayscale is replaced by the ratio of the values ​​within the new grayscale 0 to 256, where the former is considered to be part of the grayscale 180 to 256. This shows the diffraction pattern. The center of the square image FFT constitutes the "initial image", so this pixel is also set to 0. Then, the FFT image histogram is analyzed, and the main consideration criterion is the highest gray value in the image. The higher the gray value, the stronger the diffraction effect will be. So then, all designs all classifications follow this maximum gray value.

[0114] like Figure 3a to Figure 3c The diagram shows the electrical signal that can be added to one set of electrodes. The other electrode set on the interdigital system will have an opposite waveform. This waveform is made up of 3 different phases.

[0115] P1: Open phase

[0116] P2: Open state to maintain phase

[0117] P3: Close phase

[0118] Depending on the ink characteristics, the P1 phase can be applied in several ways: by increasing the potential in DC mode (for fast-drying inks), or as a high-frequency AC signal (greater than 10 Hz) (for slow-drying inks).

[0119] The P2 phase consists of a high frequency signal (greater than 10 Hz) that may correspond to an interruption of the ink stability for a determined time. The potential may be reduced during this phase compared to the P1 phase. In practice, a high voltage may be required to bring the particles to the electrode (sufficient electric field forces need to be formed for particles further from the electrode). When the particle approaches the electrode, a low potential may then be applied to obtain the same attractive force on the particle locally.

[0120] Phase P3 is the closing phase. For slow-drying inks, a low-frequency AC signal (less than 1Hz) can be applied. Compared with P1, the potential will also be reduced because the particles do not need to move to the opposite electrode. For fast-drying inks, direct current is passed through P1. In order to maintain current balance, the closing will be exactly opposite to the P1 phase.

[0121] It should be understood that for commercial applications, one or more variations of the present system may be preferably used that are similar to those disclosed in this application and are within the spirit of the present invention.

[0122] The following clauses represent advantageous implementations.

[0123] Item 1. An optical modulator (10) for switching between a transparent state and a non-transparent state and vice versa, comprising:

[0124] a first substrate and a second substrate (11, 12), wherein the substrates are optically transparent,

[0125] At least two electrodes (13, 14) are arranged on the inner side of the substrate,

[0126] a fluid (15) disposed between the substrates, the fluid comprising nanoparticles and / or microparticles (30), wherein the particles are charged or chargeable, and wherein the particles are suitable for absorbing and,

[0127] A connector for applying an electromagnetic field to the electrodes, wherein the electromagnetic field applied to the electrodes provides movement of the nanoparticles and the microparticles from the first electrode to the second electrode and vice versa,

[0128] in

[0129] The electrode comprises a conductive material, and the resistivity of the conductive material is less than 100 nΩm at 273K.

[0130] When switched to a non-transparent state, the at least two electrodes are adapted to provide power between the electrodes parallel to the substrate, and when switched to a transparent state, the at least two electrodes are adapted to provide power between the electrodes in a direction relative to the substrate, wherein the direction is selected from: parallel to the substrate, perpendicular to the substrate, tilted relative to the substrate, and combinations thereof,

[0131] a power supply electrically connected to the at least two electrodes, wherein the power supply is adapted to provide a waveform AC alternating current, wherein at least one of amplitude, frequency and phase is applicable, and

[0132] wherein the electrode is in fluid contact with the fluid; wherein the electrode covers 1% to 30% of the surface of the substrate,

[0133] wherein the at least two electrodes form an interdigitated pattern, optionally including further branches, wherein the interdigitated pattern is a regular two-dimensional pattern, each finger of the interdigitated pattern includes at least one waveform shape, wherein the waveform shape has an amplitude A and a width W,

[0134] And the distance between the fingers is d.

[0135] Item 2. An optical modulator according to Item 1, wherein the symmetry of the waveform shape is broken, such as wherein a concave first protrusion (21) is provided at the highest point of the waveform shape, and wherein a concave or upward second protrusion (22) is provided at the lowest point of the waveform shape.

[0136] Clause 3. An optical modulator according to clause 2,

[0137] Wherein, the width of the first protrusion is greater than the width of the second protrusion.

[0138] Clause 4. An optical modulator according to clauses 1-3, wherein the distance d between the fingers is 10 μm to 500 μm, preferably 10 μm to 100 μm, and / or wherein the width W of the waveform is 50 μm to 750 μm, and / or

[0139] Wherein, the amplitude A of the waveform is 10 μm to 500 μm, and / or

[0140] wherein the distance d is 10 μm to 100 μm, and / or

[0141] Wherein, the width of the first protrusion is 10 μm to 50 μm, and / or

[0142] Wherein, the width of the second protrusion is 10 μm to 50 μm, and / or

[0143] Wherein, the width of the first protrusion is 2 to 4 times the width of the second protrusion, and / or

[0144] wherein the height h of the first protrusion is 5 μm to 20 μm, and / or wherein the height h of the second protrusion is 5 μm to 20 μm, and / or wherein the protrusion is in the form of a part of a circle or an ellipse, and / or wherein the transition from the waveform to the protrusion and vice versa is gradual.

[0145] Item 5. An optical modulator according to items 1-4, wherein the power supply is adapted to provide pulses and avoid providing pulses during intervals, such as pulses between 0.1 sec / min and 10 sec / min, and the intervals are between 0.1 seconds and 1000 seconds, preferably between 5 seconds and 600 seconds.

[0146] Item 6. An optical modulator according to items 1-5, comprising a controller, wherein the controller is suitable for maintaining an AC voltage, the positive voltage of which is 0.9 to 1.1 times the magnitude of the negative voltage, preferably 0.95 to 1.05 times its magnitude, more preferably 0.99 to 1.01 times its magnitude, such as 0.995 to 1.005 times its magnitude, and is suitable for changing the potential according to the current.

[0147] Item 7. The optical modulator according to items 1-6 comprises at least two alignment marks on each substrate for aligning the substrates, preferably so that the electrodes of the first substrate are completely aligned with the electrodes of the second substrate, and more preferably the electrodes of the first substrate are projected onto the electrodes of the second substrate.

[0148] Clause 8. An optical modulator according to clauses 1-7, wherein:

[0149] operating the power supply at an AC frequency for switching to a transparent state of 10 Hz to 100 Hz, and / or

[0150] operating the power supply at an AC frequency for switching to a non-transparent state at less than 1 Hz, such as 30 to 500 mHz, or

[0151] Wherein, in one switching cycle, the power supply is operated at an AC frequency for switching to a transparent state of 10 Hz to 100 Hz, and in combination with this, the power supply is initially operated at a positive voltage or a negative voltage when switching to the transparent state, and is finally operated at a negative voltage or a positive voltage when switching to the non-transparent state.

[0152] Clause 9. An optical modulator according to clauses 1-8, comprising a temperature sensor and a controller, wherein the temperature sensor contacts the controller, wherein the controller contacts the power supply, and wherein the controller is adapted to compensate the output of the power supply based on a temperature measured by the temperature sensor.

[0153] Clause 10. An optical modulator according to clauses 1-9, wherein the fluid is a polar fluid with a dielectric constant less than 15, such as a branched or unbranched C8C 60 Alkanes, branched or unbranched C8C 60 Olefins, branched or unbranched C6C 60Alcohols, branched or unbranched C6C 60 Alkenols, branched or unbranched C8C 60 Ketones, branched or unbranched C8C 60 Aldehydes, silicone oils, and combinations thereof.

[0154] Clause 11. An optical modulator according to clauses 1-10, wherein the dynamic viscosity of the fluid is 500 mPa.s or less, preferably 50 mPa.s or less, such as less than 1 mPa.S.

[0155] Clause 12. An optical modulator according to clauses 1-11, wherein the fluid has a relative permittivity εr of less than 100, preferably less than 10.

[0156] Item 13. An optical modulator according to items 1-12, wherein the waveform power can be characterized by a frequency between 0.01 Hz and 100 Hz and an amplitude variation of 5% to 100% of the maximum amplitude, wherein the maximum amplitude is the maximum voltage operation, and is characterized by a phase variation (phase shift) between 0° and 180°.

[0157] Clause 14. A method of operating an optical modulator according to clauses 1-13, comprising:

[0158] Apply an electric field,

[0159] Move the nanoparticles and / or microparticles from the electrode to the fluid, apply a reverse electric field to move the nanoparticles and / or microparticles to diffuse outward to the electrode,

[0160] using an alternating current with two phases having a potential between -220 V and +220 V and a current between -100 μA and +100 μA, wherein the electron consumption between the two phases is substantially the same, thereby balancing the positive and negative currents,

[0161] wherein during the first phase, the electrode material partially dissolves in the fluid, and wherein during the first phase offset by +180 degrees, the dissolved electrode material is redeposited on the electrode.

[0162] Clause 15. The method of Clause 14, wherein the dissolved electrode material is deposited at the reversely charged electrode.

Claims

1. An optical electrophoretic modulator for switching between a transparent state and a non-transparent state and vice versa, the optical electrophoretic modulator comprising: a first substrate and a second substrate, wherein the first substrate and the second substrate are optically transparent, at least two electrodes, on each of the first substrate and the second substrate, the at least two electrodes being arranged on the inner side of the corresponding first substrate or the second substrate, a fluid disposed between the first substrate and the second substrate, the fluid comprising nanoparticles and / or microparticles, wherein the particles are charged or chargeable, and wherein the particles are adapted to absorb light, A connector for applying an electromagnetic field to the at least two electrodes, wherein the electromagnetic field applied to the electrodes provides movement of the nanoparticles and / or microparticles from a first electrode to a second electrode of the at least two electrodes and vice versa, wherein the at least two electrodes comprise a conductive material having a resistivity of less than 100 nΩm at 273K, wherein the at least two electrodes are adapted to provide electrical power therebetween parallel to the first substrate and the second substrate when switched to a non-transparent state, and wherein when switched to the transparent state, the at least two electrodes are adapted to provide power therebetween in a direction relative to the first substrate and the second substrate, wherein the direction is selected from: parallel to the first substrate and the second substrate, perpendicular to the first substrate and the second substrate, tilted relative to the first substrate and the second substrate, and combinations thereof, a power supply electrically connected to the at least two electrodes, wherein the power supply is adapted to provide a waveform alternating current, wherein at least one of amplitude, frequency and phase is applicable, wherein two of the at least two electrodes form an interdigitated pattern on both the first substrate and the second substrate, wherein the power supply is operated at an AC frequency of 10 Hz to 100 Hz for switching to the transparent state, and / or the power supply is operated at an AC frequency of less than 1 Hz for switching to the non-transparent state, or Wherein within one switching cycle, the power supply is operated at an AC frequency of 10 Hz to 100 Hz for switching to a transparent state, and in combination with this, the power supply is initially operated at a positive voltage or a negative voltage when switching to the transparent state, and is finally operated at a negative voltage or a positive voltage when switching to a non-transparent state.

2. The optical electrophoretic modulator of claim 1, wherein the at least two electrodes cover 1% to 30% of the substrate surface.

3. The optical electrophoretic modulator of claim 1, wherein the waveform shape symmetry is broken. 4 . The optical electrophoretic modulator according to claim 1 , wherein a concave first protrusion is provided at the highest point of the waveform shape, and wherein a concave or upward second protrusion is provided at the lowest point of the waveform shape. 5 . The optical electrophoretic modulator of claim 4 , wherein the first protrusion has a width greater than a width of the second protrusion.

6. The optical electrophoretic modulator according to claim 4, The width W of the waveform is 50 μm to 750 μm, and / or The amplitude A of the waveform is 10 μm to 500 μm, and / or wherein the distance d between the fingers is 10 μm to 500 μm, and / or wherein the width of the first protrusion is 10 μm to 50 μm, and / or The width of the second protrusion is 10 μm to 50 μm, and / or wherein the width of the first protrusion is 2 to 4 times the width of the second protrusion, and / or wherein the height h of the first protrusion is 5 μm to 20 μm, and / or wherein the height h of the second protrusion is 5 μm to 20 μm, and / or The protrusion is in the form of a part of a circle or an ellipse.

7. The optical electrophoretic modulator of claim 1, wherein the power supply is adapted to provide pulses and to refrain from providing pulses during intervals therebetween.

8. The optical electrophoretic modulator of claim 1, further comprising a controller, wherein the controller is adapted to maintain an alternating current having a positive current magnitude of 0.9 to 1.1 times the negative current magnitude, and to vary the potential in accordance with the current.

9. The optical electrophoretic modulator according to claim 1 further includes at least two alignment marks on each of the first substrate and the second substrate, for aligning the first substrate and the second substrate so that at least two electrodes of the first substrate are fully aligned with at least two electrodes of the second substrate.

10. The optical electrophoretic modulator of claim 1, further comprising a temperature sensor and a controller, wherein the temperature sensor contacts the controller, wherein the controller contacts the power supply, and wherein the controller is adapted to compensate an output of the power supply based on a temperature measured by the temperature sensor.

11. The optical electrophoretic modulator of claim 1, wherein the fluid comprises a non-polar fluid having a dielectric constant of less than 15, the non-polar fluid being selected from the group consisting of: a branched or unbranched C8-C 60 Alkanes, branched or unbranched C8-C 60 Olefins, branched or unbranched C6-C 60 Alcohols, branched or unbranched C6-C 60 Alkenols, branched or unbranched C8-C 60 Ketones, branched or unbranched C8-C 60 Aldehydes, silicone oils, and their combinations.

12. The optical electrophoretic modulator of claim 1, wherein the size of the nanoparticles is 20 nm to 1000 nm.

13. The optical electrophoretic modulator of claim 1, wherein the particles are adapted to absorb light having a wavelength of 10 nm to 1 μm.

14. The optical electrophoretic modulator of claim 1, wherein a distance between the first substrate and the second substrate is less than 500 μm.

15. The optical electrophoretic modulator according to claim 1, The dynamic viscosity of the fluid is 500 mPa·s or less.

16. The optical electrophoretic modulator of claim 1, wherein the fluid has a relative permittivity ε less than 100. r .

17. An optical electrophoretic modulator according to claim 1, wherein the waveform alternating current is characterized by a frequency of 0.01 Hz to 100 Hz, a maximum amplitude variation between 5% and 100%, wherein the maximum amplitude is a maximum voltage operation, and a phase variation (phase shift) of 0 to 180°.

18. A switching method for an optical electrophoretic modulator for switching between a transparent state and a non-transparent state and vice versa, the optical electrophoretic modulator comprising: a first substrate and a second substrate, wherein the first substrate and the second substrate are optically transparent, at least two electrodes, on each of the first substrate and the second substrate, the at least two electrodes being arranged on the inner side of the corresponding first substrate or the second substrate, a fluid disposed between the first substrate and the second substrate, the fluid comprising nanoparticles and / or microparticles, wherein the particles are charged or chargeable, and wherein the particles are adapted to absorb light, A connector for applying an electromagnetic field to the at least two electrodes, wherein the electromagnetic field applied to the electrodes provides movement of the nanoparticles and / or microparticles from a first electrode to a second electrode of the at least two electrodes and vice versa, wherein the at least two electrodes comprise a conductive material having a resistivity of less than 100 nΩm at 273K, and a power supply electrically connected to the at least two electrodes, wherein the power supply is adapted to provide a waveform alternating current, wherein at least one of amplitude, frequency and phase is applicable, and wherein two of the at least two electrodes form an interdigitated pattern on the first substrate and the second substrate, the method comprising: providing power between the at least two electrodes parallel to the first substrate and the second substrate, switching to a non-transparent state, and Providing power between the at least two electrodes in a direction relative to the first substrate and the second substrate to switch to a transparent state, wherein the direction is selected from: parallel to the first substrate and the second substrate, perpendicular to the first substrate and the second substrate, inclined relative to the first substrate and the second substrate, and a combination thereof, wherein the power supply is operated at an AC frequency of 10 Hz to 100 Hz for switching to the transparent state, and / or the power supply is operated at an AC frequency of less than 1 Hz for switching to the non-transparent state, or Wherein within one switching cycle, the power supply is operated at an AC frequency of 10 Hz to 100 Hz for switching to a transparent state, and in combination with this, the power supply is initially operated at a positive voltage or a negative voltage when switching to the transparent state, and is finally operated at a negative voltage or a positive voltage when switching to a non-transparent state.

19. An optical electrophoretic modulator for switching between a transparent state and a non-transparent state and vice versa, the optical electrophoretic modulator comprising: a first substrate and a second substrate, wherein the first substrate and the second substrate are optically transparent, at least two electrodes, on each of the first substrate and the second substrate, the at least two electrodes being arranged on the inner side of the corresponding first substrate or the second substrate, a fluid disposed between the first substrate and the second substrate, the fluid comprising nanoparticles and / or microparticles, wherein the particles are charged or chargeable, and wherein the particles are adapted to absorb light, A connector for applying an electromagnetic field to the at least two electrodes, wherein the electromagnetic field applied to the electrodes provides movement of the nanoparticles and / or microparticles from a first electrode to a second electrode of the at least two electrodes and vice versa, wherein the at least two electrodes comprise a conductive material having a resistivity of less than 100 nΩm at 273K, wherein the at least two electrodes are adapted to provide electrical power therebetween parallel to the first substrate and the second substrate when switched to a non-transparent state, and wherein when switched to the transparent state, the at least two electrodes are adapted to provide power therebetween in a direction relative to the first substrate and the second substrate, wherein the direction is selected from: parallel to the first substrate and the second substrate, perpendicular to the first substrate and the second substrate, tilted relative to the first substrate and the second substrate, and combinations thereof, a power supply electrically connected to the at least two electrodes, wherein the power supply is adapted to provide a waveform alternating current, wherein at least one of amplitude, frequency and phase is applicable, and wherein two of the at least two electrodes form an interdigitated pattern on the first substrate and the second substrate, and The waveform alternating current is characterized by a frequency of 0.01 Hz to 100 Hz, a maximum amplitude varying between 5% and 100%, wherein the maximum amplitude is a maximum voltage operation, and a phase variation (phase shift) of 0 to 180°.

20. A switching method of an optical electrophoretic modulator for switching between a transparent state and a non-transparent state and vice versa, the optical electrophoretic modulator comprising: a first substrate and a second substrate, wherein the first substrate and the second substrate are optically transparent, at least two electrodes, on each of the first substrate and the second substrate, the at least two electrodes being arranged on the inner side of the corresponding first substrate or the second substrate, a fluid disposed between the first substrate and the second substrate, the fluid comprising nanoparticles and / or microparticles, wherein the particles are charged or chargeable, and wherein the particles are adapted to absorb light, A connector for applying an electromagnetic field to the at least two electrodes, wherein the electromagnetic field applied to the electrodes provides movement of the nanoparticles and / or microparticles from a first electrode to a second electrode of the at least two electrodes and vice versa, wherein the at least two electrodes comprise a conductive material having a resistivity of less than 100 nΩm at 273K, and a power supply electrically connected to the at least two electrodes, wherein the power supply is adapted to provide a waveform alternating current, wherein at least one of amplitude, frequency and phase is applicable, and wherein two of the at least two electrodes form an interdigitated pattern on the first substrate and the second substrate, the method comprising: providing power between the at least two electrodes parallel to the first substrate and the second substrate, switching to a non-transparent state, and Providing power between the at least two electrodes in a direction relative to the first substrate and the second substrate to switch to a transparent state, wherein the direction is selected from: parallel to the first substrate and the second substrate, perpendicular to the first substrate and the second substrate, inclined relative to the first substrate and the second substrate, and a combination thereof, The waveform alternating current is characterized by a frequency of 0.01 Hz to 100 Hz, a maximum amplitude varying between 5% and 100%, wherein the maximum amplitude is a maximum voltage operation, and a phase variation (phase shift) of 0 to 180°.

21. An optical electrophoretic modulator for switching between a transparent state and a non-transparent state and vice versa, the optical electrophoretic modulator comprising: a first substrate and a second substrate, wherein the first substrate and the second substrate are optically transparent, at least two electrodes, on each of the first substrate and the second substrate, the at least two electrodes being arranged on the inner side of the corresponding first substrate or the second substrate, a fluid disposed between the first substrate and the second substrate, the fluid comprising nanoparticles and / or microparticles, wherein the particles are charged or chargeable, and wherein the particles are adapted to absorb light, A connector for applying an electromagnetic field to the at least two electrodes, wherein the electromagnetic field applied to the electrodes provides movement of the nanoparticles and / or microparticles from a first electrode to a second electrode of the at least two electrodes and vice versa, wherein the at least two electrodes comprise a conductive material having a resistivity of less than 100 nΩm at 273K, wherein the at least two electrodes are adapted to provide electrical power therebetween parallel to the first substrate and the second substrate when switched to a non-transparent state, and wherein when switched to the transparent state, the at least two electrodes are adapted to provide power therebetween in a direction relative to the first substrate and the second substrate, wherein the direction is selected from: parallel to the first substrate and the second substrate, perpendicular to the first substrate and the second substrate, tilted relative to the first substrate and the second substrate, and combinations thereof, a power supply electrically connected to the at least two electrodes, wherein the power supply is adapted to provide a waveform alternating current, wherein at least one of amplitude, frequency and phase is applicable, and wherein two of the at least two electrodes form an interdigitated pattern on the first substrate and the second substrate, The optical electrophoresis modulator further comprises a controller adapted to maintain an alternating current, wherein a positive current magnitude of the alternating current is 0.9 to 1.1 times a negative current magnitude, and adapted to change the potential according to the current.

22. A switching method for an optical electrophoretic modulator for switching between a transparent state and a non-transparent state and vice versa, the optical electrophoretic modulator comprising: a first substrate and a second substrate, wherein the first substrate and the second substrate are optically transparent, at least two electrodes, on each of the first substrate and the second substrate, the at least two electrodes being arranged on the inner side of the corresponding first substrate or the second substrate, a fluid disposed between the first substrate and the second substrate, the fluid comprising nanoparticles and / or microparticles, wherein the particles are charged or chargeable, and wherein the particles are adapted to absorb light, A connector for applying an electromagnetic field to the at least two electrodes, wherein the electromagnetic field applied to the electrodes provides movement of the nanoparticles and / or microparticles from a first electrode to a second electrode of the at least two electrodes and vice versa, wherein the at least two electrodes comprise a conductive material having a resistivity of less than 100 nΩm at 273K, and a power supply electrically connected to the at least two electrodes, wherein the power supply is adapted to provide a waveform alternating current, wherein at least one of amplitude, frequency and phase is applicable, and wherein two of the at least two electrodes form an interdigitated pattern on the first substrate and the second substrate, the method comprising: providing power between the at least two electrodes parallel to the first substrate and the second substrate, switching to a non-transparent state, and Providing power between the at least two electrodes in a direction relative to the first substrate and the second substrate to switch to a transparent state, wherein the direction is selected from: parallel to the first substrate and the second substrate, perpendicular to the first substrate and the second substrate, inclined relative to the first substrate and the second substrate, and a combination thereof, wherein the optical electrophoresis modulator further comprises a controller, and The method includes maintaining, by the controller, an alternating current whose positive current magnitude is 0.9 to 1.1 times that of a negative current magnitude, and varying the potential according to the current.

Images