DEVICE FOR THE REGULATION OF LIGHT TRANSMISSION

Abstract

The present application discloses a switchable device, comprising a switching layer and a first conductive layer and a second conductive layer, where the switching layer is positioned between the first and the second conductive layer, and where at least one of the first and the second conductive layers comprises a plurality of isolating sections and a plurality of conductive sections, where the isolating sections and the conductive sections alternate over the area of the conductive layer, and where the switching state of the switchable device is controlled by touch motions.

Claims

1. Switchable device for the regulation of light transmission, comprising a stack of layers which comprises a first substrate layer, a second substrate layer, a switching layer which is positioned between the first and the second substrate layer, a first conductive layer which is positioned between the switching layer and the first substrate layer, and a second conductive layer which is positioned between the switching layer and the second substrate layer, where the switching layer comprises a material which changes its light transmissivity upon the application of voltage, and where at least one of the first and the second conductive layers comprises a plurality of isolating sections and a plurality of conductive sections, where the isolating sections and the conductive sections alternate over the area of the conductive layer, and where the switching state of the switchable device is controlled by touch motions.

2. Switchable device according to claim 1, characterized in that the isolating sections and the conductive sections alternate in a regular pattern over the area of the conductive layer.

3. Switchable device according to claim 1, characterized in that for each one of the plurality of conductive sections, the switching state of the specific section of the switching layer which is covered by the area of the conductive section can be selected independently of the switching state of the other sections of the switching layer.

4. Switchable device according to claim 3, characterized in that the switching state of each of the specific sections of the switching layer which can be selected independently is controlled by touch motions on a touch sensitive layer.

5. Switchable device according to claim 1, characterized in that the isolating sections are lines with a width of 0.2 μm to 100 μm, preferably 1 μm to 75 μm, particularly preferably 10 μm to 50 μm.

6. Switchable device according to claim 1, characterized in that the isolating sections are lines which are parallel to each other and which are regularly spaced, with a distance between the parallel lines of in each case between 1 μm and 1 m, where the conductive sections are positioned in the space between the lines.

7. Switchable device according to claim 1, characterized in that the first and the second conductive layer comprises a thin layer of metal, preferably silver, or of other material, where the other material is preferably selected from metal oxide, more preferably from transparent conductive metal oxide (TCO), particularly preferably from indium tin oxide (ITO), fluorinated tin oxide (FTO), and aluminium doped tin oxide (AZO), or from silver nanowires, carbon nanotubes, graphene, conductive polymers, in particular PEDOT:PSS, a metal mesh, or silver nanoparticles.

8. Switchable device according to claim 1, characterized in that the isolating sections of the conducting layer are created by a method selected from laser ablation, chemical etching, laser photolithography, mechanical embossing techniques, and photo embossing; or by sputtering an ITO (indium tin oxide) or similar conductive material coating as a conductive layer while certain sections are covered, and later on remove the covering material to obtain a glass section without the coating; or by coating conductive material only in specific sections by inkjet printing of solution processable conductors.

9. Switchable device according to claim 1, characterized in that only one of the first and the second conductive layers comprises a plurality of isolating sections, and the other one of the first and the second conductive layers comprises no or essentially no isolating sections.

10. Switchable device according to claim 1, characterized in that a part of one of the first and the second conductive layers does not overlap in the stack with the other of the first and the second conductive layers, preferably is freely accessible from at least one side, and that this part is electrically connected to voltage.

11. Switchable device according to claim 10, characterized in that the part of one of the first and the second conductive layers which does not overlap in the stack with the other of the first and the second conductive layers has overlapping areas with each of the conductive sections of the conductive layer, where preferably, in these overlapping areas, the conductive sections are each separately electrically connected to voltage.

12. Switchable device according to claim 1, characterized in that the conductive sections of one of the first and the second conductive layers are each separately and independently electrically contacted with a power source by a means selected from direct addressing, passive matrix addressing, active matrix addressing and multiplex driving.

13. Switchable device according to claim 1, characterized in that a touch sensitive layer is present inside or on the stack of layers of the switchable device, or in an external touch sensitive device which is connected to the switchable device by electrical wiring or by wireless connection, such as by WiFi, bluetooth or IR transmitter.

14. Switchable device according to claim 1, characterized in that it comprises an interconnected assembly, comprising a touch sensitive layer, an assembly comprising one or more logic units, preferably a programmable logic controller (PLC) or a computer, which translates the output signals of the touch sensitive layer into output signals, one or more voltage sources whose output voltage can be varied depending on an input signal, and a plurality of switches which are capable of switching each one of the plurality of conductive segments on and off, depending on an input signal.

15. Switchable device according to claim 14, characterized in that each of the switches of the plurality of switches is connected to a separate power source with independently adjustable voltage.

16. Switchable device according to claim 1, characterized in that the switching layer is selected from electrochromic switching layers, suspended particle switching layers, electrophoretic switching layers and liquid crystal switching layers.

17. Switchable device according to claim 16, characterized in that the liquid crystal switching layers are selected from polymer comprising liquid crystal switching layers and from small molecule based liquid crystal switching layers.

18. Switchable device according to claim 16, characterized in that the liquid crystal switching layers are selected from polymer comprising liquid crystal switching layers, which are polymer dispersed liquid crystal switching layers.

19. Switchable device according to claim 16, characterized in that the liquid crystal switching layer comprises one or more dichroic dyes dissolved in a liquid crystalline material, where the liquid crystalline material comprises one or more liquid crystalline organic compounds, which are selected from small molecules and polymeric materials.

20. Switchable device according to claim 1, characterized in that the switching layer is switched by application of an electric field between at least two different switching states, where one of the states is a dark state or a scattering state, and the other state is a clear state.

21. Switchable device according to claim 20, characterized in that in the dark state, the liquid crystalline material is in a state selected from nematic non-twisted, nematic twisted and nematic supertwisted, whereas in the clear state, the material is in a homeotropic state.

22. Switchable device, characterized in that it comprises a stack, comprising a first switchable device and a second switchable device, wherein both the first and second devices are according to claim 1.

23. Window, comprising a switchable device according to claim 1, preferably characterized in that it comprises an insulated glass unit, where the switchable device is positioned inside of the insulated glass unit.

24. Window according to claim 23, characterized in that it comprises a separate touch sensitive device, which is preferably positioned on a frame of the window.

25. A building or a vehicle, comprising a switchable device according to claim 1, or comprising a window that comprises said switchable device.

Description

LIST OF FIGURES

[0097] FIG. 1 shows a side view of a the stack of layers of a switchable device according to the present application.

[0098] FIG. 2 shows a side view of a the stack of layers of a switchable device according to the present application, being part of an IGU.

[0099] FIG. 3 shows a side view of a the stack of layers of a switchable device according to the present application, being part of an IGU, where two switchable devices according to the present application are stacked on top of each other to form a double liquid crystal (LC) cell device.

[0100] FIG. 4 shows a front view of a conductive layer according to the present application, which has a plurality of conductive sections, and a plurality of isolating sections.

[0101] FIG. 5 shows a front view of a first conductive layer and a second conductive layer stacked on top of each other, where the two conductive layers do not fully overlap.

[0102] FIG. 6 shows a side view of a the stack of layers of a switchable device according to the present application, where the two conductive layers do not fully overlap.

[0103] FIG. 7 shows an assembly of electrical components connected to the switchable device.

[0104] FIG. 7a shows an alternative assembly of electrical components connected to the switchable device.

[0105] FIG. 8 shows schematically position and form of touch gestures performed on the surface of the switchable device.

[0106] FIG. 9 shows the signal applied to the segmented substrate, according to a first mode of operation of the device.

[0107] FIG. 10 shows the signal applied to the non-segmented substrate, and the signal applied to the segmented substrate, according to a second mode of operation of the device.

LISTING OF REFERENCE NUMBERS

[0108] 1 first substrate layer [0109] 2 first conductive layer [0110] 2a the part of the first conductive layer which does not overlap in the stack with the second conductive layer [0111] 2b the part of the first conductive layer which overlaps in the stack with the second conductive layer [0112] 3 switching layer [0113] 4 second conductive layer [0114] 5 second substrate layer [0115] 6 conductive sections of the first conductive layer [0116] 6a the parts of the conductive sections of the first conductive layer which do not overlap with the second conductive layer [0117] 6b the parts of the conductive sections of the first conductive layer which overlap with the second conductive layer [0118] 7 isolating sections of a conductive layer [0119] 8a gas-filled space [0120] 8b spacer [0121] 9 solid layer, preferably glass layer [0122] 10 touch sensitive layer [0123] 11 touch sensitive device [0124] 12 computer [0125] 13 programmable logic controller (PLC) [0126] 13a analog output of the PLC [0127] 13b digital output of the PLC [0128] 14 AC voltage source [0129] 15 GND [0130] 15a common voltage [0131] 15b signal voltage [0132] 16 switching device, comprising a plurality of switches [0133] 17 connections of the switches to the conductive sections of the conductive layer of the switchable device [0134] 18 common output [0135] A single tap gesture on a segment [0136] B vertical drag gesture on the right of the window [0137] C horizontal drag gesture on the bottom of the window [0138] D double tap gesture in a region at the bottom right of the window

[0139] The following working examples serve to illustrate the present invention. They are not to be construed as limiting the invention in any way beyond the limitations as set out in the claims.

WORKING EXAMPLES

1) Preparation of a Switchable Window Having a Segmented Structure

[0140] Four sheets of conductive ITO coated glass (80 nm thickness of ITO layer) are obtained commercially. To obtain segmented panels, on two of these sheets, electrically isolated sections are created by laser ablation of the ITO coating. For this, an excimer laser is used with an intensity of 300 mJ/cm.sup.2 and >40 pulses per position. The intensity of the laser is adapted to the thickness of the ITO layer. The segments are created in a pattern of regularly spaced lines as shown in FIG. 4. To avoid visibility of the laser lines in the final product, the line width is chosen to be 25 μm. The other two sheets of conductive ITO coated glass are not treated by laser ablation.

[0141] After washing all four sheets, polyimide is printed on their ITO coating. The substrates are then baked in an oven and the polyimide is rubbed to obtain alignment layers. Subsequently, the four substrates are arranged as two liquid crystal (LC) cells, with alignment layers facing inside, each consisting of both a segmented and a non-segmented sheet. A small non-overlapping area of the sheets is created on the side, having a width of 3-5 mm, which allows to contact all segments (see FIG. 6, simplified scheme for a single LC cell, not showing the alignment layers). The cells are filled with a dye doped liquid crystal mixture in a 25 μm cell gap in twisted nematic configuration. The mixture used is the same as the one used in published patent application WO 2014/135240, named mixture “H2”, in combination with 0.11 weight % of dye D1, 0.15 weight % of dye D2 and 0.23 weight % of dye D3, where the dyes D1, D2 and D3 are mentioned under these names in the above patent application as well.

[0142] Both thus obtained LC cells are then combined to a double cell structure as schematically shown in FIG. 3, to obtain a switchable window with dye doped double LC cell layout. A capacitive touch foil (commercially obtained from Pro Display, Hoyland, U.K.) is attached to the outer side of the outer glass sheet, as schematically shown in FIG. 3.

[0143] Electrical wiring is applied to all conductive sections of the sheets in the accessible positions.

2) Contacting of the Window to the Touch Sensitive Foil to Arrive at a Touch Controllable Window

[0144] In accordance with the scheme shown in FIG. 7, each of the conductive sections of the two LC cells is connected to a separate switch, which is capable of switching the respective section between GND and a power supply (0-24 V AC). The switches are controlled using digital outputs (DO) of a programmable logic controller (PLC). The voltage of the power supply is also set by the PLC, controlled by an analog output of the PLC. The touch foil is connected to a PC which runs the corresponding drivers and contains software which defines specific touch areas and the effect of gestures on the touch sensitive foil. The PC is connected to the PLC to determine the desired window state after a touch event.

[0145] The touch areas and touch gestures defined in the software allow to control the greyscale of the device using a horizontal drag motion, to switch individual segments with a touch, to switch all segments simultaneously with a double touch and to switch consecutive segments by a vertical drag motion, thereby mimicking blinds.

[0146] FIG. 8 shows the effect of touch gestures to the liquid crystal window: a single tap switches the segment in the corresponding area between its on and off states (A). On the side of the window there is a region (B) where a vertical drag down motion results in switching the segments consecutively to dark (starting from the top segment and continuing until the drag motion stops) or a drag up motion results in switching the segments consecutively to bright (starting from the bottom and continuing until the drag motion stops), resulting in a partly switched window. On the bottom there is a region (C) where a drag to the left results in dimming of segments that are switched on and a drag to the right increases the brightness of segments that switched on. A double tap in the region on the bottom right (D) switches all segments between the dark and the bright state. The dashed lines in FIG. 8 indicate the positioning of the segments (isolated sections of the conductive layer created by laser ablation).