A laminated glazing stack with integrated PDLC, and methods of controlling and manufacturing thereof

Abstract

A LAMINATED GLAZING STACK WITH INTEGRATED PDLC, AND METHODS OF CONTROLLING AND MANUFACTURING THEREOF Present disclosure relates to a laminated glazing stack designed for precise and efficient segment control. It comprises a plurality of glass layers, transmitting and receiving conductive loops (302a, 302b respectively) formed on separate substrate layers, which may be inductively coupled to enable wireless power transfer. Each pair of transmitting and receiving loops (302a, 302b) may correspond to a specific segment of the PDLC display. Conductive electrodes (204) connected to these conductive loops (302a, 302b), may regulate the applied voltage for controlling segment transparency. Further, a controller (402) may be configured to generate control signals to manage voltage levels across the segments, while a digital circuit may produce gate signals 508 to adjust the optical state of each segment based on these control signals. This innovative design and the associated PDLC display device and method may ensure accurate segment activation, minimize crosstalk, and facilitate dynamic control of the PDLC display.

Description

A LAMINATED GLAZING STACK WITH INTEGRATED PDLC, AND METHODS OF CONTROLLING AND MANUFACTURING THEREOFTECHNICAL FIELD

[0001] The present invention generally relates to the field oflaminated glazings. More particularly, the present disclosure relates to providing a laminated glazing stack with integrated PDLC and wireless powering layers, and methods of controlling and manufacturing the laminated glazing stack with integrated PDLC.BACKGROUND

[0002] The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] Polymer Dispersed Liquid Crystal (PDLC) displays are smart glass technologies where liquid crystal droplets are dispersed in a polymer matrix. They switch between transparent and opaque states when an electric field is applied. Commonly used for privacy glass and projection screens, PDLC displays may thereby provide adjustable light transmission and energy efficiency. In today’s world, the PDLC displays have become crucial for advanced projection systems, offering versatile applications in advertising, augmented reality, interactive displays, and the like. Additionally, PDLC displays support sustainability by reducing reliance on blinds or curtains, enhancing energy efficiency, and improving aesthetics in smart technology applications. They are increasingly used in healthcare, offices, and luxury vehicles for privacy and dynamic control of light.

[0004] However, existing PDLC displays face several challenges that impact their efficiency and usability. One major issue is power distribution across multiple segments, which can result in uneven performance, increased energy consumption, crosstalk between the segments or localized overheating. The complexity of managing this power distribution may further grow with the number of segments, complicating the system's design and operation. Also, the existing PDLC displays rely on physical connectors for powering the segments.

[0005] Another drawback involves control mechanisms, particularly when wireless technologies like infrared (IR) protocols are used. IR signals can be absorbed or reflected by laminated glass with Ultraviolet (UV) or IR coatings, reducing the reliability of such control systems. Additionally, the manufacturing processes for PDLC displays often involve intricate techniques for selective deposition of conductive coatings. These methods may limit precision and increase production complexity. Furthermore, current approaches may not adequately address the challenges of wirelessly powering advanced configurations like pixelated structures, adding another layer of difficulty to the development of more efficient and versatile PDLC displays.

[0006] There is therefore a need to provide robust techniques for controlling and manufacturing a wireless segmented PDLC display device which may overcome the drawbacks / challenges associated with the existing technologies.SUMMARY

[0007] The present disclosure overcomes one or more shortcomings of the prior art and provides additional advantages. Embodiments and aspects of the disclosure described in detail herein are considered a part of the claimed disclosure.

[0008] In one embodiment of the present disclosure, a laminated glazing stack has been disclosed.The laminated glazing stack comprises a plurality of glass layers. Further, the laminated glazing stack comprises a plurality of transmitting conductive loops formed on one or more layers of the glass layers such that each of the transmitting conductive loop corresponds to a segment of a plurality of segments of the PDLC display device. The laminated glazing stack further comprises a plurality of receiving conductive loops formed on a layer of the plurality of substrate layers of the Polymer Dispersed Liquid Crystal (PDLC) display device such that each of the receiving conductive loop corresponds to a segment of the plurality of segments of the PDLC display device. Further, the plurality of transmitting conductive loops is inductively coupled to the plurality of receiving conductive loops. The laminated glazing stack further comprises a plurality of conductive electrodes coupled to the plurality of transmitting conductive loops, for controlling the plurality of segments of the PDLC display device. Furthermore, the laminated glazing stack comprises a controller coupled to the plurality of conductive electrodes such that the controller is configured to generate one or more control signals for regulating a voltage applied to each segment of the plurality of segments of the PDLC display device. The laminated glazing stack further comprises a digital circuitconfigured to generate a plurality of gate signals for controlling an optical state of each segment of the plurality of segments, based on the one or more control signals.

[0009] In yet another non-limiting embodiment of the present disclosure, the plurality of transmitting conductive loops and the plurality of receiving conductive loops are inductively coupled for wirelessly transferring power to the plurality of segments of the PDLC display device.

[0010] In yet another non-limiting embodiment of the present disclosure, the plurality of transmitting conductive loops is connected to an Alternating Current (AC) voltage source via a power connection line in the first layer of the PDLC display device for generating a time-varying magnetic field.

[0011] In yet another non-limiting embodiment of the present disclosure, the plurality of receiving conductive loops is formed within a pre-defined proximity to the plurality of transmitting conductive loops such that a time-varying magnetic field generated in the plurality of transmitting conductive loops induces an AC voltage in the plurality of receiving conductive loops.

[0012] In yet another non-limiting embodiment of the present disclosure, the plurality of transmitting conductive loops (302a) are formed on outer side or inner side of the plurality of glass layers.

[0013] In yet another non-limiting embodiment of the present disclosure, the plurality of receiving conductive loops (302b) are etched or printed on the plurality of the substrate layers of the PDLC display device.

[0014] In yet another non-limiting embodiment of the present disclosure, the digital circuit comprises one or more shift registers arranged sequentially, and coupled to a plurality of transistors corresponding to the plurality of segments of the PDLC display device.

[0015] In yet another non-limiting embodiment of the present disclosure, the plurality of transistors in conjunction with the controller is configured to receive the plurality of gate signals from the one or more shift registers for controlling respective segment of the PDLC display device.

[0016] In yet another non-limiting embodiment of the present disclosure, the controller is configured to provide a full voltage from the AC voltage source to one or more selected segments of the plurality of segments and a voltage in pre-defined ratio of the full voltage to remaining segments of the plurality of segments.

[0017] In yet another non-limiting embodiment of the present disclosure, a method of controlling an optical state of a laminated glazing stack has been disclosed. The method comprising generating, by a controller in a PDLC display device, one or more control signals for regulating a voltage applied to each segment of a plurality of segments of the PDLC display device. The method further comprises generating, by a digital circuit in the PDLC display device, a plurality of gate signals for controlling the optical state of each segment of the plurality of segments, based on the one or more control signals.

[0018] In yet another non-limiting embodiment of the present disclosure, the method further comprises transmitting the plurality of gate signals to a plurality of transistors corresponding to the plurality of segments of the PDLC display device, for controlling respective segment of the PDLC display device.

[0019] In yet another non-limiting embodiment of the present disclosure, the method further comprises providing a full voltage from the AC voltage source to one or more selected segments of the plurality of segments and a voltage in pre-defined ratio of the full voltage to remaining segments of the plurality of segments.

[0020] In yet another non-limiting embodiment of the present disclosure, a method of manufacturing a laminated glazing stack has been disclosed. The method comprising arranging a plurality of glass layers and then forming a plurality of transmitting conductive loops on a layer of the plurality of glass layers . Each of the transmitting conductive loop among the plurality of transmitting conductive loops corresponds to a segment of a plurality of segments of the PDLC display device. The method further comprises forming a plurality of receiving conductive loops on a layer of the plurality of substrate layers of PDLC display device, each receiving conductive loop corresponds to a segment of the plurality of segments of the PDLC display device such that the plurality of transmitting conductive loops is inductively coupled to the plurality of receiving conductive loops.

[0021] In yet another non-limiting embodiment of the present disclosure, the method further comprises inductively coupling the plurality of transmitting conductive loops and the plurality of receiving conductive loops for wirelessly transferring power to the plurality of segments of the PDLC display device.

[0022] In yet another non-limiting embodiment of the present disclosure, the method further comprises connecting the plurality of transmitting conductive loops to an Alternating Current(AC) voltage source via a power connection line in the first layer of the PDLC display device for generating a time-varying magnetic field.

[0023] In yet another non-limiting embodiment of the present disclosure, the method further comprises forming the plurality of receiving conductive loops within a pre-defined proximity to the plurality of transmitting conductive loops such that a time-varying magnetic field generated in the plurality of transmitting conductive loops induces an AC voltage in the plurality of receiving conductive loops.

[0024] In yet another non-limiting embodiment of the present disclosure, the method further comprises etching or printing the plurality of receiving conductive loops (302b) on the plurality of the substrate layers of the PDLC display device.

[0025] In yet another non-limiting embodiment of the present disclosure, the method further comprises forming the plurality of transmitting conductive loops (302a) on outer side or inner side of the plurality of glass layers.

[0026] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.BRIEF DESCRIPTION OF DRAWINGS

[0027] The features, nature, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout. Some embodiments of system and / or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and with reference to the accompanying Figs., in which:

[0028] Fig. 1 depicts an exemplary structure of an existing laminated glazing stack comprising a PDLC display, in accordance with embodiments of the present disclosure;

[0029] Fig. 2 depicts exemplary view of a segmented PDLC display, in accordance with embodiments of the present disclosure;

[0030] Fig. 3A depicts an exemplary architecture of the laminated glazing stack and the integration of various layers to enable the implementation of the segmented wireless PDLC display device, in accordance with embodiments of the present disclosure;

[0031] Fig. 3B depicts the PDLC display being segmented via the intersection of the plurality of conductive electrodes along with an exemplary protocol for voltage distribution, in accordance with embodiments of the present disclosure;

[0032] Fig. 4 depicts an exemplary block diagram of the Electrical Control Unit (ECU) which may enable the management of power and control processes within the PDLC display device, in accordance with embodiments of the present disclosure;

[0033] Fig. 5 depicts an exemplary diagram of a shift register to enable segment-specific control of the PDLC display device, in accordance with the embodiment of the present disclosure;

[0034] Fig. 6 depicts an exemplary circuit of a flyback diode which may serve as a protective mechanism for the proposed PDLC display device, in accordance with the embodiment of the present disclosure;

[0035] Fig. 7 depicts a block diagram of a laminated glazing stack, in accordance with the embodiment of the present disclosure;

[0036] Fig. 8 is a flowchart showing steps of a method for controlling an optical state of a laminated glazing stack, in accordance with embodiments of the present disclosure; and

[0037] Fig. 9 is a flowchart showing steps of a method of manufacturing a laminated glazing stack, in accordance with embodiments of the present disclosure.

[0038] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in a computer readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.DETAILED DESCRIPTION

[0039] The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure.

[0040] The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

[0041] In the present document, the word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment or implementation of the present subject matter described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0042] While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.

[0043] The terms “comprise”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device, or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a device or system or apparatus proceeded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the device or system or apparatus.

[0044] The terms “an embodiment”, “embodiment”, “embodiments”, “the embodiment”, “the embodiments”, “one or more embodiments”, “some embodiments”, and “one embodiment” mean “one or more (but not all) embodiments of the invention(s)” unless expressly specified otherwise.

[0045] The terms “including”, “comprising”, “having” and variations thereof mean “including but not limited to” unless expressly specified otherwise.

[0046] The terms “PDLC display device”, “PDLC device”, “PDLC system” and “proposed system” have been used interchangeably in the present disclosure.

[0047] The terms “segment”, “segments” and “PDLC segments” have been used interchangeably in the present disclosure.

[0048] The terms “controller”, “Electrical Control Unit (ECU)” and “processor” have been used interchangeably in the present disclosure.

[0049] The detailed description of the present disclosure follows a logical progression where the key elements needed in the manufacturing of the proposed PDLC device may be introduced first. Subsequently, roles and interconnections of the key elements while highlighting their functionality and advantages may be discussed. Figs. 1-5 in conjunction with the forthcoming paragraphs describe the key elements of the proposed PDLC device along with the interactions among the key elements to implement the proposed wireless segmented PDLC display device.

[0050] Fig. 1 depicts an exemplary structure of an existing laminated glazing stack 100 comprising a PDLC display which may further consist of multiple layers designed to achieve smart lightcontrol functionality. The outermost layer in the laminated glazing stack 100 may comprise of glass layers 102, which provide rigidity, protection, and optical clarity. Beneath the glass layers 102, Polyvinyl Butyral (PVB) layers 104 may be stacked, which may act as an adhesive interlayer to bond the glass layers 102 to the core functional layer while enhancing strength and flexibility. The central layer may consist of a PDLC film 106, where liquid crystal droplets are dispersed within a polymer matrix. The PDLC film 106 may be sandwiched between conductive layers such as electrodes, which apply an electric field to the liquid crystals. When a voltage is applied, the liquid crystals may align, allowing light to pass through and making the PDLC display transparent. In the absence of voltage, the liquid crystals may scatter light, rendering the PDLC display opaque. This layered arrangement may thereby enable the PDLC display to function as smart glass for privacy and adaptive lighting applications. The PDLC display may further be segmented into a plurality of sections as explained in the upcoming paragraphs in conjunction with Fig. 2 of the present disclosure.

[0051] Fig. 2 depicts exemplary view 200 of a segmented PDLC display. In the Fig. 2, the PDLC display being segmented into a plurality of segments 202 have been illustrated. In one embodiment, the plurality of segments 202 may be formed by intersection of a plurality of conductive electrodes 204. The formation of such intersections has been explained in detail in conjunction with Fig. 3B of the present disclosure. The segments 202 may be further comprising the liquid crystals 206 have been illustrated such that in one embodiment, the liquid crystals 206 may align, allowing light to pass through and making the PDLC display transparent. In another embodiment, in the absence of voltage, the liquid crystals 206 may scatter light, rendering the PDLC display opaque. Further, each segment 202 may further comprise the conductive loops on the various layers of the substrate and the plurality of conductive electrodes 204 may serve a critical functionality in the functioning of the laminated glazing stack by generating the electric fields needed to control the optical properties of the proposed laminated glazing stack. In one embodiment, the plurality of conductive electrodes 204 may be made of Indium Tin Oxide (ITO) which may be described as a transparent and electrically conductive material, etched and patterned into precise grids The manufacturing and design of these conductive loops along with their integration with the proposed laminated glazing stack have been explained in the forthcoming paragraphs in conjunction with the Fig.3 A and Fig. 3B of the present disclosure.

[0052] Fig. 3A depicts an exemplary architecture 300A of the proposed laminated glazing stack and the integration of various layers to enable the implementation of the segmented wireless PDLC display. In Fig. 3A, conductive loops 302 have been illustrated which may be defined as one of the most crucial components in the proposed laminated glazing stack responsible for enabling wireless power transfer and ensuring precise control over the PDLC display device’s functionality. The PDLC display device is formed by roll to roll coating or sputtering for the electrode section. In one embodiment, the conductive loops 302 may be referred to as the intricately patterned conductive pathways formed on the glass and substrate layers of the PDLC display device. In one embodiment, the conductive loops 302 in the PDLC display device may be formed using different processes such as etching and printing depending on the desired precision, material properties, manufacturing approach, and the like. In the etching process, a conductive material such as Indium Tin Oxide (ITO) may be uniformly coated onto the substrate, and specific patterns may be created by removing unwanted material using techniques like photolithography, laser etching, or chemical etching. The etching process may particularly be useful for forming intricate and highly precise conductive loops 302, such as those needed for transmitting and receiving purposes. Alternatively, the conductive loops 302 may also be formed using printing techniques, such as inkjet or screen printing, where conductive inks like silver nanoparticle-based inks, graphene, carbon nanotube (CNT), butnot limited thereto, may be deposited directly onto the substrate in the desired patterns. Inkjet based digital printing is especially advantageous for creating complex patterns efficiently, while also enabling the integration of transparent ITO layers for optical functionality of the PDLC display device.

[0053] In one embodiment, the conductive loops 302 may be formed on a laminated glazing stack, as being discussed in the foregoing paragraphs such that the proposed laminated glazing stack may comprise a glass layer 102, topped by the PVB layer 104 and then a pixelated PDLC layer 306 on which the conductive loops 302 may be etched or printed. The conducive loops 302 may further comprise a plurality of transmitting conductive loops 302a and a plurality of receiving conductive loops 302b such that each of them may be serving a distinct and crucial purpose. The plurality of transmitting conductive loops 302a may be located on any given layer of the glass layer such as a base layer, but not limited thereto, and may be responsible for generating a time-varying magnetic field when connected to an AC power source. The plurality of transmitting conductive loops 302a, as discussed in the foregoing paragraphs, may be formed using fabrication techniques such as digital printing with conductive inks or etching on conductive materials like Indium Tin Oxide (ITO). A person skilled in the art will appreciate that forming of the plurality of transmitting conductive loops 302a may be performed using other techniques, and the above-mentioned techniques should be considered limiting. The design and integration of the plurality of transmitting conductive loops 302a may facilitate efficient generation of a uniform magnetic field for reliable inductive energy transfer. In one non-limiting embodiment, the plurality of transmitting conductive loops 302a may be open loops connected to a conductive line 304. On the other hand, the plurality of receiving conductive loops 302b may be positioned on any layer of the substrate such that the substrate layer comprising the plurality of receiving conductive loops 302b may be present above the layer comprising the plurality of transmitting conductive loops 302a and the plurality of receiving conductive loops 302b may be formed as closed loops, as depicted. In addition to this, in another embodiment, the conductive loops 302 may also be placed either on outer / inner surface of the glass layers 102 or in the PVB layers 104 or in the substrate of the proposed laminated glazing stack. Further, the plurality of receiving conductive loops 302b may be inductively coupled to the plurality of transmitting conductive loops 302a and may not be connected to any electrical power source as such. This arrangement of placing the plurality of receiving conductive loops 302b in any given layer above the layer comprising the plurality of transmitting conductive loops 302a may ensure precise alignment to facilitate optimal inductive coupling between the plurality of transmitting conductive loops 302a and the plurality of receiving conductive loops 302b. The plurality of receiving conductive loops 302b may thereby receive the magnetic field generated by the plurality of transmittingconductive loops 302a and convert it into an alternating voltage, which may then be used to power the plurality of segments 202 of the PDLC display device. In one embodiment, like the plurality of transmitting conductive loops 302a, the plurality of receiving conductive loops 302b may also be fabricated using similar techniques to ensure seamless integration and efficient energy transfer across the device. The collaboration between these two types of conductive loops 302 is central to the wireless inductive powering mechanism of the proposed laminated glazing stack. In one embodiment, the proximity between the plurality of transmitting conductive loops 302a and the plurality of receiving conductive loops 302b may be carefully controlled to maintain a thin gap with the corresponding dielectrics of the conductive loops 302 to ensure minimal energy loss and optimal power transfer. In a nonlimiting exemplary scenario, the gap may be maintained at less than 1mm. A person skilled in the art will appreciate that the above-mentioned value is exemplary and should not be considered as limiting.

[0054] In another embodiment, instead of arranging the plurality of transmitting conductive loops 302a and the plurality of receiving conductive loops 302b into different layers of the substrate, the conductive loops 302 may be incorporated into a segment-wise addressing system, as illustrated in Fig. 3B of the present disclosure.

[0055] Fig. 3B depicts the PDLC display being segmented via. the intersection of the plurality of conductive electrodes 204. In the Fig. 3B, the formation of each segment 202 in the PDLC display device may involve a meticulous integration of a plurality of conductive electrodes 204 and substrate to create individually controllable segment 202. In one embodiment, the substrate may typically be made up of transparent materials like glass or flexible polymers but not limited thereto. The substrate may serve as the foundation for constructing the conductive and insulating layers in the proposed laminated glazing stack. In another embodiment, the substrate in the PDLC display device may serve as the foundational structure upon which all functional layers, including conductive loops 302 and the plurality of conductive electrodes 204 may be built / etched. The substrate may provide mechanical support, electrical insulation, and optical clarity among others thereby ensuring the proper functioning of the proposed laminated glazing stack. In yet another embodiment, the substrate may act as a platform for the creation of transmitting conductive loops 302a and receiving conductive loops 302b, which are critical for inductive coupling and wireless power transfer, as envisaged by the present disclosure. The substrate may thereby integrate the conductive loops and other functional layers, such as insulating layers and the plurality of conductive electrodes 204, into a cohesive structure. This may enable the segment 202 of the proposed laminated glazing stack to be individually controlled with precision. The use of advanced substrate fabricationtechniques may further enhance the performance, reliability, and scalability of the PDLC display device, making it suitable for a wide range of applications.

[0056] For instance, the plurality of transmitting conductive loops 302a may be etched into rows 204A, while the plurality of receiving conductive loops 302b may be etched into columns 204B. At each intersection of these loops, the formed segment 202 may be independently controlled. On one side of the proposed laminated glazing stack, the ITO may be patterned into rows 204A where each row, in one non-limiting embodiment, may be measuring 100 mm x 500 mm, with a 5 mm gap between each row to ensure electrical isolation. The rows 204A may thereby act as one set of electrodes. In another non-limiting embodiment, the ITO may be patterned into columns 204B, on the opposing side, measuring 500 mm x 100 mm, forming a set of counter electrodes. This arrangement of rows 204A and columns 204B may thereby allow the creation of a crisscross grid structure. The etching process may ensure high precision, enabling the plurality of conductive electrodes 204 to maintain excellent electrical conductivity and transparency. The plurality of conductive electrodes 204 may play a pivotal role in uniformly applying electric fields across the PDLC film 106, enabling effective and localized control over the PDLC display device. This design enables precise optical control of each segment 202, creating a matrix structure for displaying dynamic patterns or information which has been discussed in detail in the forthcoming paragraphs in conjunction with Figs.4-5 of the present disclosure.

[0057] In another embodiment, the functional integration of these conductive loops 302 with an Electrical Control Unit (ECU), as depicted in Fig. 4, may enable in modulating the power transfer, enabling a full voltage to be applied to specific segments while supplying a predefined fraction of this voltage to other remaining segments. This selective voltage regulation is vital for achieving varied transparency or opacity states across the display, enhancing its usability for dynamic applications. The selective activation and inactivation of the plurality of segments 202 in the proposed laminated glazing stack may be essential for precise control of transparency or opacity within the device. The segment-specific addressing may facilitate high-quality visual performance, as it may allow the individual segments 202 of the proposed laminated glazing stack to operate independently without interference. However, a major challenge in achieving this independence is crosstalk, a phenomenon where the electric field intended for one segment may unintentionally influence adjacent segments. Crosstalk may thereby cause unintended transparency or opacity changes in neighbouring segments, leading to distortions in the PDLC display's functionality and appearance. Such interference may compromise the uniformity and precision required in applications like smart windows, automotive displays, and other segmented PDLC systems.

[0058] To overcome the issue of crosstalk, the proposed laminated glazing stack proposes a mechanism of supplying predefined voltages to the plurality of segments 202 such that by carefully designing the voltage distribution across the rows 204A and columns 204B of the proposed laminated glazing stack, stray fields may be minimized, ensuring that only the intended segment 202 is activated while others remain unaffected. One exemplary embodiment of this approach is the V / 3 protocol 306, which may apply a systematic voltage scheme to address individual segments effectively. In the V / 3 protocol 306, for instance, the addressed column b may be powered with 12 V, while unaddressed columns (a and c) are supplied with a lower voltage of 4 V. Simultaneously, the addressed row 1 may be grounded at 0 V, and all other rows (2 and 3) are maintained at 3 V. This voltage scheme may ensure that the intersection of the addressed row 1 and column b may receive the full effective voltage required for activation, while all other segments experience partial voltages insufficient to trigger a state change. The V / 3 protocol 306 may thereby enhance the PDLC display device's reliability by mitigating crosstalk and ensuring accurate segment activation. By maintaining strict control over voltage distribution, the V / 3 protocol 306 may support precise and independent segment operation, thereby improving the visual quality, efficiency, and performance of PDLC displays in advanced applications.

[0059] In yet another embodiment, conductive lines 304 may also be embedded into the proposed laminated glazing stack to establish reliable electrical pathways between different components of the proposed laminated glazing stack. These conducive lines 304 may also be referred to as the conductive electrodes 204, as depicted in Fig. 2 of this disclosure. These conductive lines 304 may facilitate low-resistance conduction, ensuring efficient signal transmission and power distribution across the conductive loops 302, digitally printed transmitter and receiver layers, and the powering electrodes. Their integration is essential for enabling the smooth operation of the individual display segments, ensuring uniform voltage application and consistent optical performance. In one embodiment, the conductive lines 304 may be embedded using the variety of conductive materials like copper, silver, brass, aluminium but not limited thereto. However, a key advantage of using silver metal for embedding the conductive lines 304 is silver’s exceptional electrical conductivity, which may minimize energy losses and enhance the overall efficiency of the proposed laminated glazing stack. Additionally, the transparency of the silver metal for the conductive lines 304 may make them aesthetically pleasing, as they seamlessly blend into the display without obstructing the viewer’s visual experience as the aesthetic integration may form a critical necessity in modem display designs where unobstructed clarity and sleek appearance are highly valued. In addition to this, the silver conductive lines 304 may not only strengthen the electrical connectionsbetween the conductive loops 302 but also improve the mechanical durability and reliability of the proposed laminated glazing stack as a whole.

[0060] Fig. 4 depicts an exemplary block diagram 400 of the ECU 402 which may enable the management and control of power within the proposed laminated glazing stack, in accordance with the embodiments of the present disclosure. The ECU 402 may also be referred as controller, processor, digital signal processor among others. In one embodiment, the ECU 402 may serve as the central system of the proposed laminated glazing stack. As depicted in the Fig. 4, the ECU 402 may consist of several critical components such as an input fdter and protection circuit 404, a Direct Current-Direct Current (DC-DC) converter 406, a Direct Current- Alternating Current (DC-AC) converter 408, and a segment controller 410, but not limited thereto. These elements may work together to ensure that power is efficiently transferred from the conductive loops 302 to the plurality of segments 202 while maintaining the stability and safety of the proposed laminated glazing stack.

[0061] In the ECU 402, the input filter and protection circuit 404 may be responsible for safeguarding the proposed laminated glazing stack from electrical anomalies such as electromagnetic interference (EMI), overvoltage, undervoltage, reverse voltage, and input surges. The circuit may be of more importance in wireless power transfer systems, where external environmental factors may affect the incoming power signal. The filtered and stabilized output of the input filter and protection circuit 404 may then be sent to the DC-DC converter 406, which may adjust the voltage to the requisite level for the proposed laminated glazing stack. Depending on the design, the DC-DC converter 406 may be isolated or non-isolated to ensure compatibility with the specific power demands. The DC-AC converter 408 may then transform the direct current (DC) to alternating current (AC), which may be required to drive the plurality of segments 202. The segment controller 410 may then enable the selective activation of the plurality of segments 202 depending on the requirement. The segment controller 410 may comprise the logic and switching mechanisms for facilitating the selective activation of the plurality of segments 202.

[0062] For the proposed laminated glazing stack, the ECU 402 may be integrated with the conductive loops 302 for facilitating the wireless power transfer in the PDLC display device. The plurality of transmitting conductive loops 302a, as discussed in the forthcoming paragraphs, may be powered by the external AC source to generate the alternating magnetic field that may induce a corresponding current in the plurality of receiving conductive loops 302b embedded in the substrate layer of the PDLC display device. These plurality of receiving conductive loops 302b may be connected to the ECU 402 such that the incoming inductive power from theplurality of transmitting conductive loops 302a may be processed through the ECU 402 and regulated to appropriate voltage levels, for distribution to the plurality of segments 202 of the PDLC display device. The ECU 402 may, in turn, further ensure that the power is delivered efficiently and in a controlled manner to the plurality of segments 202. In addition to this, the ECU 402 may also play a pivotal role in connecting to the shift registers, as the signals controlling the plurality of segments 202 are shared between the ECU 402 and the shift register, which have been explained in detail in the upcoming paragraphs in conjunction with Fig. 5 of the present disclosure. Nevertheless, the ECU 402 may be integral to the operation of the PDLC display device, as it may bridge the power transfer from the conductive loops 302 and the control mechanism of the shift registers. The ability of the ECU 402 to process and regulate power while coordinating control signals may ensure efficient and reliable functionality for wireless power transfer in the segmented PDLC display device.

[0063] Fig. 5 depicts an exemplary diagram 500 of a shift register 502 to enable the segment-specific control of the proposed laminated glazing stack, in accordance with the embodiment of the present disclosure. As discussed, the shift register 502 may be working in conjunction with the ECU 402 for controlling the PDLC display device such that the segment controller 410 of the ECU 402 may be configured to communicate with the shift register 502 to send the serial data 504 (hereinafter referred as “data") when the data enable 506 is turned ON. The data 504 may encode the activation pattern for the corresponding segments 202. This data 504 may then be transmitted in sync with clock (CLK) signals to the shift registers 502, which may be further configured to decode the data 504 into parallel signals. Each parallel output of the shift register 502 may be connected to the gate of the transistor which may serve as a switch for directing power to a specific PDLC segment 202. By selectively activating the plurality of transistors, the shift register 502, under the control of the ECU 402, may allow precise management of which the plurality of segments 202 may be powered at any given time.

[0064] In one embodiment, the shift register 502 may be a digital integrated circuit (IC) responsible for sequentially controlling multiple outputs based on clock (CLK) and data inputs received from the ECU 402. In the Fig. 5, an exemplary 8-bit serial-in parallel-out shift register has been depicted whose IC may consist of key components like data inputs (A and B), a clock (CLK) input, clear (CLR), a power supply (Vcc), and ground (GND). The data inputs (A and B) may be configured to receive the serial data 504, which may be loaded bit by bit into the shift register 502. The clock (CLK) input may be configured to govern the timing, ensuring that data shifts sequentially through the shift register 502 at each clock pulse. The clear (CLR) input may be essential for resetting the IC, ensuring all outputs (Qo-Qn) are set to a known state (logic 0). The outputs, labelled Qo to Qn, may represent the parallel outputs of the shiftregister 502, where the sequential data is presented simultaneously. A decoupling capacitor connected to Vcc may stabilize the IC’s operation by filtering out noise and voltage fluctuations. This configuration may thereby allow the shift register 502 to control plurality of gate signals for plurality of transistors connected to the plurality of segments 202 for enabling independent switching of the corresponding segment 202. Subsequently, the shift register 502 may sequentially processes the received data and generate parallel outputs, which may serve as a plurality of gate signals 508 for the plurality of transistors connected to the plurality of conductive electrodes 204 of the proposed laminated glazing stack. By switching these plurality of transistors, via the output of the shift register 502, the ECU 402 may independently control the transparency of each PDLC segment 202. Fig. 5 is only an exemplary diagram illustrating the shift register 502 to enable the segment-specific control of the proposed laminated glazing stack. However, the type / number of the elements / components shown in Fig. 5 may vary based on implementation and should not be considered as limiting. Also, Fig. 5 shows only one shift register for illustration purposes. However, there may be multiple shift registers based on the number of segments of the PDLC display of the proposed laminated glazing stack to be controlled or other implementation requirements. Further, the proposed laminated glazing stack may also comprise a flyback diode, the function and integration of which has been discussed in detail in the upcoming paragraphs in conjunction with Fig. 6 of the present disclosure.

[0065] Fig.6 depicts an exemplary circuit 600 of a flyback diode 602 which may serve as a protective mechanism for the proposed laminated glazing stack. The flyback diode 602 may be positioned in parallel with the conductive loops 302, to mitigate the harmful effects of back electromotive force (EMF) generated during the operation of inductive transfer of the power between the transmitting conductive loop 302a and the receiving conductive loop 302b. In one embodiment, when the shift register 502 sequentially activates plurality of transistors to control specific segments 202 of the PDLC display device, the rapid switching of current through conductive loops 302 may result in the generation of back EMF as the magnetic field may collapse when the current is interrupted. This back EMF may create high-voltage spikes that may damage the plurality of transistors, disrupt the functionality of the shift register 502, or degrade the stability of the entire proposed laminated glazing stack. The fly-back diode 602 may become forward-biased when the transistor switches off, allowing the back EMF to circulate within the circuit loop formed by the inductor and the diode itself. This process may thereby prevent voltage spikes from reaching sensitive components like the shift register 502 or adjacent circuitry. The seamless integration of the flyback diode 602 with the shift register 502 may ensure that the shift register 502 may continue to operate effectively by providing precise control signals to the plurality of transistors without the risk of malfunction due tovoltage surges. This protective function is essential for the stable and reliable operation of the proposed laminated glazing stack, particularly in applications involving wireless power transfer and rapid switching technologies. The working of the proposed laminated glazing stack as a system and the interaction of all the system components has been discussed in detail in the upcoming paragraphs in conjunction with the Fig. 8 of the present disclosure.

[0066] Fig. 7 depicts a block diagram 700 of a proposed laminated glazing stack 702 to wirelessly control the transparency of the segmented PDLC display device. The laminated glazing stack 702 may comprise multiple interconnected components, each playing a distinct role to achieve the desired functionality. These components may include conductive loops (CLs) 302, the plurality of conductive electrodes 204, an Input / Output (I / O) interface 704, a digital circuit 706 (which houses one or more shift registers 502 and plurality of transistors 708), a memory module 710, the ECU 402, and an AC voltage source 712. The conductive loops 302 may be further segregated into the plurality of transmitting conductive loops 302a and the plurality of receiving conductive loops 302b. In one embodiment, the plurality of transmitting conductive loops 302a may be powered by the AC voltage source 712 to create an alternating magnetic field. The magnetic field may then be inductively transferred to the plurality of receiving conductive loops 302b which may be embedded near or within the PDLC display. This inductive coupling may thereby enable wireless power transfer, eliminating the need for direct electrical connections and ensuring operational flexibility. The received power is then regulated and supplied to the system's 702 other components.

[0067] The plurality of conductive electrodes 204 may be positioned within the system 702 to apply specific voltage levels across the liquid crystal material. This voltage may alter the alignment of liquid crystal molecules, controlling the transparency or opacity of each segment 202. The design and placement of the plurality of conductive electrodes 204 are crucial to ensure accurate voltage application and to prevent unintended activation of adjacent segments such as crosstalk. Further, the digital circuit 706, in one embodiment, may comprise shift registers 502 and plurality of transistors 708 which may be configured to manage the sequencing and activation of the plurality of segments 202. The shift registers 502 may be configured to temporarily store and sequentially send the control signals, received from the ECU 402 to the plurality of transistors 708, which may act as switches. These plurality of transistors 708 may, in turn, be configured to regulate the voltage delivered to specific conductive electrodes 204, ensuring that only the intended segments are activated at a given time. The memory module 710 may be configured to store the control patterns and operational data, which may be retrieved by the ECU 402 during operation. The ECU 402 may further be configured to serve as the central management unit, orchestrating the flow of data and ensuring synchronizedinteractions between all components. In one embodiment, the entire process is coordinated by the ECU 402, which may be further configured to communicate with the digital circuit 706 via the I / O interface 704. The I / O interface may be configured to act as a bridge, enabling smooth data transfer between the ECU 402, shift registers 502, and other components. The ECU 402 may also be configured to retrieve the operational instructions from the memory 710 and oversees the sequence of events, from wireless power transfer to segment activation.

[0068] Fig. 8 is a flowchart showing steps of a method 800 for controlling an optical state of a proposed laminated glazing stack, in accordance with embodiments of the present disclosure. The method 800 may also be described in the general context of computer executable instructions. Generally, computer executable instructions may include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform specific functions or implement specific abstract data types.

[0069] The order in which the method 800 is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described.

[0070] At step 802, the method 800 may include generating one or more control signals for regulating a voltage applied to each segment of the plurality of segments 202 of the PDLC display device. In one embodiment, the one or more control signals may be generated by the ECU 402 of the PDLC display device.

[0071] At step 804, the method 800 may include generating the plurality of gate signals 508 for controlling the optical state of each segment of the plurality of segments 202, based on the one or more control signals. In one embodiment, the plurality of gate signals 508 may be generated by a digital circuit 706 of the PDLC display device.

[0072] Fig. 9 is a flowchart showing steps of a method 900 of manufacturing a proposed laminated glazing stack, in accordance with embodiments of the present disclosure. The method 900 may also be described in the general context of computer executable instructions. Generally, computer executable instructions may include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform specific functions or implement specific abstract data types.

[0073] The order in which the method 900 is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described.

[0074] At step 902, the method 900 may include arranging a plurality of glass layers.

[0075] At step 904, the method 900 may include forming the plurality of transmitting conductive loops 302a on a first layer of a plurality of glass layers . In one non-limiting embodiment, each of the plurality of transmitting conductive loops 302a may correspond to a segment of the plurality of segments 202 of the PDLC display device.

[0076] At step 906, the method 900 may include forming the plurality of receiving conductive loops 302b on a layer of the plurality of substrate layers, each receiving conductive loop corresponds to a segment of the plurality of segments 202 of the PDLC display device. In one non-limiting embodiment, the plurality of transmitting conductive loops is inductively coupled to the plurality of receiving conductive loops.

[0077] The illustrated steps are set out to explain the exemplary embodiments shown, and it should be anticipated that ongoing technological development will change the manner in which particular functions are performed. These examples are presented herein for purposes of illustration, and not limitation. Further, the boundaries of the functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternative boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. It may be noted here that the subject matter of some or all embodiments described with reference to Figures 1-7 may be relevant for the method and the same is not repeated for the sake of brevity.

[0078] Alternatives (including equivalents, extensions, variations, deviations, etc., of those described herein) will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. Such alternatives fall within the scope and spirit of the disclosed embodiments. Further, any skilled person in the art would appreciate that the reconstruction error mentioned in the foregoing paragraphs may be considered as a value that overshoots the determined threshold value and must not be construed as an error as such.

[0079] Furthermore, one or more computer-readable storage media may be utilized in implementing embodiments consistent with the present disclosure. A computer-readable storage mediumrefers to any type of physical memory on which information or data readable by a processor may be stored. Thus, a computer-readable storage medium may store instructions for execution by one or more processors, including instructions for causing the processor(s) to perform steps or stages consistent with the embodiments described herein. The term “computer- readable medium” should be understood to include tangible items and exclude carrier waves and transient signals, i.e., are non-transitory. Examples include random access memory (RAM), read-only memory (ROM), volatile memory, non-volatile memory, hard drives, CD ROMs, DVDs, flash drives, disks, and any other known physical storage media.

[0080] Suitable processors include, by way of example, a general-purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a graphic processing unit (GPU), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and / or a state machine.

[0081] As used herein, a phrase referring to “at least one” or “one or more” of a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c. The terms “a”, “an” and “the” mean “one or more”, unless expressly specified otherwise.

[0082] Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the disclosure be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the embodiments of the present disclosure are intended to be illustrative, but not limiting, of the scope of the disclosure, which is set forth in the appended claims.

Claims

CLAIMS1. A laminated glazing stack comprises:a plurality of glass layers;a plurality of transmitting conductive loops (302a) formed on a layer of the plurality of glass layers, wherein each transmitting conductive loop (302a) corresponds to a segment of a plurality of segments (202) of the PDLC display device;a plurality of receiving conductive loops (302b) formed on a layer of the plurality of substrate layers of the Polymer Dispersed Liquid Crystal (PDLC) display device, each receiving conductive loop (302b) corresponds to a segment of the plurality of segments (202) of the PDLC display device, wherein the plurality of transmitting conductive loops (302a) is inductively coupled to the plurality of receiving conductive loops (302b); a plurality of conductive electrodes (204) coupled to the plurality of transmitting conductive loops (302a) and the plurality of receiving conductive loops (302b), for controlling the plurality of segments (202) of the PDLC display device;a controller (402) coupled to the plurality of conductive electrodes (204), configured to:generate one or more control signals for regulating a voltage applied to each segment of the plurality of segments (202) of the PDLC display device; and a digital circuit (706) configured to:generate a plurality of gate signals (508) for controlling an optical state of each segment of the plurality of segments (202), based on the one or more control signals.

2. The laminated glazing stack as claimed in claim 1, wherein the plurality of transmitting conductive loops (302a) and the plurality of receiving conductive loops (302b) are inductively coupled for wirelessly transferring power to the plurality of segments (202) of the PDLC display device.

3. The laminated glazing stack as claimed in claim 1, wherein the plurality of transmitting conductive loops (302a) is connected to an Alternating Current (AC) voltage source (712) via a power connection line for generating a time-varying magnetic field.

4. The laminated glazing stack as claimed in claim 1, wherein the plurality of receiving conductive loops (302b) is formed within a pre-defined proximity to the plurality of transmitting conductive loops (302a), wherein a time-varying magnetic field generated in the plurality of transmitting conductive loops (302a) induces an AC voltage in the plurality of receiving conductive loops (302b).

5. The laminated glazing stack as claimed in claim 1, wherein the plurality of transmitting conductive loops (302a) are formed on outer side or inner side of the plurality of glass layers.

6. The laminated glazing stack as claimed in claim 1, wherein the plurality of receiving conductive loops (302b) are etched or printed on the plurality of the substrate layers of the PDLC display device.

7. The laminated glazing stack as claimed in claim 1, wherein the digital circuit (706) comprises one or more shift registers (502) arranged sequentially and coupled to a plurality of transistors corresponding to the plurality of segments (202) of the PDLC display device.

8. The laminated glazing stack as claimed in claim 6, wherein the plurality of transistors is configured to receive the plurality of gate signals (508) from the one or more shift registers (502) for controlling respective segment of the PDLC display device.

9. The laminated glazing stack as claimed in claim 1, wherein the controller (402) is configured to provide a full voltage from the AC voltage source (712) to one or more selected segments of the plurality of segments (202) and a voltage in pre-defined ratio of the full voltage to remaining segments of the plurality of segments (202).

10. A method (800) of controlling an optical state of a laminated glazing stack, the method comprising:generating (802), by a controller (402) in a Polymer Dispersed Liquid Crystal (PDLC) display device, one or more control signals for regulating a voltage applied to each segment of a plurality of segments (202) of the PDLC display device; andgenerating (804), by a digital circuit (706) in the PDLC display device, a plurality of gate signals for controlling the optical state of each segment of the plurality of segments (202), based on the one or more control signals.

11. The method (800) as claimed in claim 10, comprising transmitting the plurality of gate signals to a plurality of transistors corresponding to the plurality of segments (202) of the PDLC display device, for controlling respective segment of the PDLC display device.

12. The method (800) as claimed in claim 10, comprising providing a full voltage from the AC voltage source (712) to one or more selected segments of the plurality of segments (202) and a voltage in pre-defined ratio of the full voltage to remaining segments of the plurality of segments (202).

13. A method (900) of manufacturing a laminated glazing stack, the method comprising: arranging a plurality of glass layers;forming (902) a plurality of transmitting conductive loops (302a) on a layer of the plurality of glass layers, wherein each transmitting conductive loop (302a) corresponds to a segment of a plurality of segments (202) of the PDLC display device; and forming (904) a plurality of receiving conductive loops (302b) on a layer of the plurality of substrate layers of the Polymer Dispersed Liquid Crystal (PDLC) display device, each receiving conductive loop (302b) corresponds to a segment of the plurality of segments (202) of the PDLC display device, wherein the plurality of transmitting conductive loops (302a) is inductively coupled to the plurality of receiving conductive loops (302b).

14. The method (900) as claimed in claim 13, wherein the plurality of transmitting conductive loops (302a) and the plurality of receiving conductive loops (302b) are inductively coupled for wirelessly transferring power to the plurality of segments (202) of the PDLC display device.

15. The method (900) as claimed in claim 13, wherein the plurality of transmitting conductive loops (302a) is connected to an Alternating Current (AC) voltage source (712) via a power connection line in the first layer of the PDLC display device for generating a timevarying magnetic field.

16. The method (900) as claimed in claim 13, wherein the plurality of receiving conductive loops (302b) are formed within a pre-defined proximity to the plurality of transmitting conductive loops (302a), wherein a time-varying magnetic field generated in the plurality of transmitting conductive loops (302a) induces an AC voltage in the plurality of receiving conductive loops (302b).

17. The method (900) as claimed in claim 13, wherein the plurality of receiving conductive loops (302b) are etched or printed on the plurality of the substrate layers of the PDLC display device.

18. The method (900) as claimed in claim 13, wherein the plurality of transmitting conductive loops (302a) are formed on outer side or inner side of the plurality of glass layers.

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