TWI769181B - Liquid crystal dynamic beam control device and manufacture - Google Patents

Abstract

A variable light beam is provided from a light source. The light source can be an LED light source or other source. The light source includes basic collimation optics, such as reflector or Fresnel lens, an electrically controllable LC device, such as a polydisperse LC film, in front of the incident spot light beam. Preferably the polydisperse LC film includes transparent flat uniform electrode layers. The LC device can be autonomous of the light source. The proposed solution provides a dynamically controllable, preferably polarizer-free and pixel-free, beam shape light source module including a controllable light beam control module and a light source module providing the initial light beam in a scanner light source, a camera flash, an architectural, automobile or industrial lighting device.

Description

Liquid crystal dynamic beam control device and manufacturing method

This application claims priority to US Provisional Patent Application 62/423,810, filed November 18, 2016, the contents of which are incorporated herein by reference.

The present patent application relates to liquid crystal beam dispersion control devices, methods of manufacture and integration into lamps or light sources.

The visible light source can be a light emitting diode, an incandescent light bulb, a fluorescent light source or an electroluminescent light source. For space utility lighting, also known as architectural lighting, it is known to use mirrors and/or lenses to provide a light source beam with a desired collimation or divergence. However, light emitting diodes (LEDs) are currently being used on a large scale in new installations as well as replacing previous light sources. These LED light sources already offer significant energy savings and open up the possibility of enabling emerging applications that enable dynamic control of light intensity and color, as well as LiFi-enabled (instead of or in parallel with WiFi) communications.

The light source does not provide the spatial shape of the light, the dynamic control of divergence, glare and direction. Currently this is done by combining many (hundreds of) LED light sources pointed in different directions and controlling them one by one by using a rather complex electronic device.

Currently known solutions suggest the use of complex mechanical systems of stepper motors and mirrors to obtain spatial control of light.

Liquid crystal (LC) materials have been successfully used in LC displays (LCDs) and electrically variable imaging lenses (see WO2009/153764). In those LC devices, an electric field is typically used to control the molecular orientation of the LC material in the LC cell. Changes in molecular orientation affect the local refractive index of the LC material, and thus its refractive index profile. This can change the phase of the light or its direction of polarization.

However, in order to control the light divergence, a non-uniform (dynamically controllable) refractive index profile is required. Particularly in LC lens control applications, specific refractive index gradients can result in so-called gradient index (GRIN) lenses. In another case of LCD devices, multiple electrodes are provided to achieve this modulation.

Furthermore, in order to operate on unpolarized light, LCD devices for display applications traditionally use two polarizers, which significantly reduce the optical efficiency (in terms of the direction of light transmission away from the viewer) to below 10%. Due to the deleterious reduction in optical efficiency created by the use of polarizers, applicants developed a dual LC layer structure (each layer with its ground state having an optical axis perpendicular to the other) for mobile imaging applications (cell phone cameras) to provide An electrically variable imaging lens for polarizers.

The LC imaging lenses mentioned above are typically limited to 3 mm optical apertures, which can be focused using non-segmented (no picture element) electrodes. However, LED-based lighting systems typically pump phosphor layers using blue LEDs, where the light source is Lambertian (very divergent at each point of the light source). To collimate this light source, various types of reflectors are used. This provides an output beam with more or less collimation (eg, 10 degrees, as measured by the full width half maximum value of the lateral distribution of light intensity, or FWHM). In addition, the light-passage apertures of luminaires (using such light sources) are often as large as 100 mm.

Existing LED based lighting systems have fixed beam dispersion (fixed wide dispersion or fixed spot beam). For example, Figure 1 shows a spot beam projected on a white screen by a commercially available LED light source from CREE. A "single optical via" approach does not provide enough modulation (optical path difference between different light rays) to produce a significant change in light divergence. Therefore, the projected beam size (spot or patch) will remain nearly the same size in the set scene. This has created the necessity to introduce multiple light-through (map) elements, such as arrays of linear or circular microlenses configured to add dispersion to the spot beam. This novel development is described in International Application PCT/CA2016/050589, filed May 25, 2016, the entire contents of which are incorporated herein by reference. Liquid crystal beam shaping devices are also known in the patent literature, eg US2010/0149444 published on June 17, 2010. Such a device is placed in the light path of the light beam at a distance from the light emitting part of the light source. Such equipment typically requires a power supply of about 50V and requires control of its operation.

Figure 1 shows a spot beam projected on a white screen by a commercial LED light source from CREE. Figure 2 shows a spot beam expanded using a graphed LC beam shaping device. A cruciform structure can be observed in the intensity distribution. Figure 3 shows the spot beam expanded by using an improved LC beam shaping device. The stubborn cruciform structure is reduced and the beam appears more circularly symmetric.

The use of multiple optical via elements requires an additional step of electrode etching thereby increasing its manufacturing cost. There is therefore a need to improve the cost of manufacturing dynamically variable beam shaping LC devices while maintaining the beam quality of the light source.

In some applications, the use of multi-optical via elements may be appropriate, however, like elementless LC beam expanders, integrating them into light sources remains a challenge.

A variable beam of light is emitted from the light source. The light source may be an LED light source or other light source. The light source includes substantially collimating optics, such as a reflector or a Fresnel lens, and an electrically controllable LC device, such as a polydisperse LC film, placed in front of the incident spot beam. Preferably, the polydisperse LC film comprises a transparent planar uniform electrode layer. The LC device may be independent of the light source. The proposed scheme provides a dynamically controllable, preferably polarization-independent, and primitive-free beam shape light source module comprising a controllable beam control module and light source module that provides the initial beam of the scanner light source , camera flash, architectural, automotive or industrial lighting fixtures.

The current application discloses that, in some embodiments, LC devices in which LC clumps or droplets are polydisperse and their properties (effective refractive index) can be dynamically controlled by applying an electric field, eg preferably using planar transparent electrodes uniform electric field. This eliminates the graphing of the electrodes (thus the structure is considered a single optical via device) as well as the polarizer. In some embodiments even monolayer polydisperse composites (LC-polymers, LC-particles, etc.) can be used to control the light spreading angle. In some other embodiments, two or more layers of such composite materials are described, significantly reducing the cost of equipment.

Applicants have discovered a number of features related to the optical performance of polydisperse beamforming LC devices, including the use of non-patterned, substantially uniform electrodes, which eliminate the need for polarizers and the formation of single optical vias.

According to the proposed solution, polydisperse LC droplet elements using at least one polymer dispersed liquid crystal (PDLC) in the optical path allow control of the transmitted light properties. Therefore, according to one embodiment of the proposed solution, an actively controlled PDLC film is used directly and exclusively in front of the low divergence light source to provide variable dispersion control. Preferably, the PDLC film includes a transparent planar uniform electrode layer.

According to another embodiment of the proposed scheme, an actively controlled PDLC film, driven directly from a power supply, via a voltage converter, or by pulse width modulation (PWM), is used directly and exclusively in front of an LED light source to provide variable color dispersion control. Dispersion control can be achieved with an additional DC power supply or other alternatives.

According to another embodiment of the proposed solution, the use of at least one polymer-stabilized liquid crystal (PSLC) element with polydisperse LC clusters in the optical path allows to control the transmitted beam properties. Thus, according to broad aspects of the proposed solution, actively controlled PSLC films are used directly and exclusively in the front end of low divergence light sources to provide variable dispersion control. Preferably, the PSLC film comprises a transparent planar uniform electrode layer.

In another embodiment according to the proposed solution, the use of at least two polymer-stabilized liquid crystal (PSLC) elements with polydisperse LC clusters in the optical path allows the transmission of light properties to be modified in the presence of an unpolarized incident beam better control. Therefore, according to one embodiment of the proposed solution, an actively controlled PSLC film is employed directly and exclusively before the low divergence light source to provide variable dispersion control. These PSLC films preferably comprise a transparent planar uniform electrode layer.

According to another embodiment of the proposed solution, the use of at least one micro-nanoparticle-stabilized liquid crystal (MNP-SLC) element with polydisperse LC clusters in the optical path allows control of the transmitted beam properties. Thus, according to broad aspects of the proposed solution, actively controlled MNP-SLC films are used directly and exclusively in front of low dispersion light sources to provide variable dispersion control. Preferably, the MNP-SLC film includes a transparent planar uniform electrode layer.

Depending on the proposed solution, spatially inhomogeneous, e.g. two-dimensional (2D) or three-dimensional (3D) structured polydisperse composite LC material morphologies (e.g. periodic gratings, etc.) can be employed to provide dynamic beam angle spreading, again commonly referred to as (Divergent) Dispersion control.

The applicant has also found that when the liquid crystal device is mounted at the exit aperture of the light source, the photovoltaic power drawn from the periphery of the point beam of the light source can generate a driving power in the range of 1 to 100 mW (voltage in the range of 1 to 50V) .

Applicants have also discovered that by detecting the power modulation sequence provided to the light source, the liquid crystal beam shaping or steering device can be controlled without requiring a separate control signal path to control the state of the liquid crystal device.

Applicants have further discovered that integration of the liquid crystal beam steering device can be facilitated by fitting an optical aperture suitable for a given light source's exit beam so that the liquid crystal beam steering device can be connected to the light source after fabrication.

Applicants have further discovered that providing a liquid crystal beam steering device for directional beam steering to a light source having a rotatable mounting allows different light sources to share a single beam steering direction with the liquid crystal beam steering device for different light sources.

In this application, "beam control device" refers to an optical device that can receive an input beam to provide a modulated output beam, wherein the modulation can be variably controlling the divergence or beam divergence in at least one direction or dimension, and/or Or at least the steering of the beam in one direction.

12‧‧‧Substrate

14A, 14B‧‧‧electrodes

18‧‧‧Orientation layer

20‧‧‧LC

The proposed solution will be better understood by the following detailed description of embodiments of the invention with reference to the accompanying drawings, in which: Figure 1 is an illustration of a spot beam projected by a commercial LED component supplied by CREE; Illustration showing an attempt at LED spot beam expansion via an LC beam shaping device with increased dispersion, which has an undesirable cross-shaped angular beam intensity distribution with 4 lobes; Fig. 3 is shown as Fig. 2 Illustration of another attempt at LED spot beam expansion of an LC beam shaping device in which a diffuser is used to provide a fixed amount of divergence to provide an improved angular beam intensity distribution, however with a stubborn cross-shaped beam envelope; Figure 4A is a schematic diagram showing a polymer dispersed liquid crystal (PDLC) film in which the LC domains in the ground state scatter incident light; Figure 4B is a PDLC showing a working state with coordinated orientation of the LC domains allowing transmission of incident light when driven with an electric field Schematic diagram of the apparatus; Figure 5A is a schematic diagram of a PDLC film with good polydispersity; Figure 5B is a schematic diagram showing a PDLC film with insufficient polydispersity; Figure 6A is a graph showing the measurement Figure 5A The relationship between applied voltage and light transmission of the device is described. Due to the polydispersity of the material, light transmission is gentle, occurring over a relatively wide range of control voltages; Figure 6B is a graph showing measured applied voltage versus light transmission for the device depicted in Figure 5B Fig. 7 is the light emission of the spot beam of the LED element shown in Fig. 1 through an undriven (ground state) PDLC film as described in Fig. 5A, the beam projection has good light dispersion according to the proposed solution quality without unevenness in intensity or color; Fig. 8A is the luminescence of the spot beam of the LED element shown in Fig. 1 through a PDLC film driven at 10V AC as described in Fig. 5A, according to the proposed solution Another illustration of ; Fig. 8B is another illustration of the light emission of the spot beam of the LED element shown in Fig. 1 passing through the PDLC film driven with 50V AC as described in Fig. 5A according to the proposed solution ; Fig. 8C is another illustration of the light emission of the spot beam of the LED element shown in Fig. 1 passing through the PDLC film driven by 120V alternating current as described in Fig. 5A according to the proposed solution; Fig. 9 is based on The proposed solution is a normalized polar plot showing the angular intensity distribution of the projected beam under different control conditions; Figure 10 is a schematic diagram showing a circuit diagram of an illuminator according to an embodiment of the proposed solution; Figure 11 is a schematic diagram showing a circuit diagram of another luminaire according to another embodiment of the proposed solution; Figure 12 is a circuit diagram showing another luminaire according to another embodiment of the proposed solution Figure 13 is a schematic diagram showing a circuit diagram of another luminaire according to another embodiment of the proposed solution; Figures 14A, 14B and 14C show light intensity control on one PSLC layer ( stronger on the left side of the figure). Where a) the PSLC film is located between orthogonal polarizers; b) the PSLC film is observed through a polarizer parallel to the original direction of the LC molecules; c) the PSLC film is observed through a polarizer perpendicular to the original direction of the LC molecules. (VVPRESNYAKOV, TVGALSTIAN, "Light Polarizer Based on Anisotropic Nematic Gel with Electrically Controlled Anisotropy of Scattering", MC & LC, Molecular Crystals and Liquid Crystals, Volume 413, 2004-issue 1); Fig. 15 is a schematic diagram of the control of the polarization component T _⊥ , T _∥ of light transmission, and the polarization efficiency of T _⊥ /T _∥ of the polymerized PSLC sample at a temperature of 56℃ as a function of the applied voltage (VVPRESNYAKOV, TVGALSTIAN, "Light Polarizer Based on Anisotropic Nematic Gel with Electrically Controlled Anisotropy of Scattering", MC & LC, Molecular Crystals and Liquid Crystals, Volume 413, 2004-issue 1); Figures 16, 16B, 16C and 16D are photomicrographs showing elastic self-assembly and patterning of topological microparticles for providing scattering/dispersion centers. Figure 16A is an optical micrograph showing hexagonal ordering in a densely packed toron array with large area grains separated by grain boundaries. Figures 16B to 16D show polarized optical micrographs depicting the transition from (Figure 16B) isotropic repulsive interactions mediating the formation of hexagonal arrays to (Figure 16C) weakly anisotropic attractive interactions resulting in Topological grain crystallites with small periodicity, and (Fig. 16D) highly anisotropic interactions lead to voltage-controlled transitions of toron-cable dipoles (Paul J. Ackerman, Jao van de Lagemaat, & Ivan I. Smalyukh, "Self-assembly and electrostriction of arrays and chains of hopfion particles in chiral liquid crystals", NATURE COMMUNICATIONS | DOI: 10.1038/ncomms7012, 2015) ; Fig. 17 is a schematic diagram of an application system with functions such as light intensity adjustment and expansion; Fig. 18 is a schematic perspective view of a liquid crystal beam steering device having an arrangement on the outer circumference of a circular device An annular photovoltaic strip or ring with liquid crystal control electrode drive circuits and control circuits disposed at the edge of the device; Figure 19A is a schematic cross-section of a device with four LC cells mounted on a light source according to Figure 18; Figure 19B is a schematic cross-section of a device similar to Figure 18 with a polymer-dispersed liquid crystal material mounted on a light source; Figure 20A is a type of "directional manipulation" using in-plane electrodes on one substrate of the cell. "Schematic cross-sectional view of LC beam expansion cell design; Figure 20B is a schematic cross-sectional view of 4 LC cells according to Figure 20A combined to provide beam expansion control in two directions perpendicular to two linear (or orthogonal) polarized unpolarized light; Figure 20C shows how patterned interdigitated electrodes are arranged on one substrate in one direction on a substantially circular liquid crystal beam steering device; Figure 20D is a graph of relative intensity as a function of angle of a given light source and different voltages applied to the device of Fig. 20B; Fig. 21A is an experimental image of a focused spot beam from a laser light source when the liquid crystal beam steering element is turned off, showing Two side-by-side beams from the light source are directed in parallel with a small spacing between them; Figure 21B shows the same spot beam of Figure 21A being driven at the liquid crystal beam steering element, and the two liquid crystal beam steering devices are With the patterned electrodes co-aligned, the spot beam is widened in both directions; Figure 21C shows the same spot beam of Figure 21A being driven at the LC beam steering element, and the pattern of the two LC beam steering devices In the case of misaligned electrodes, the spot beam is widened in both directions; Fig. 22 shows the Side view of a ring circuit board with PV elements mounted to one side of an embodiment; Figure 23 shows a schematic block of an example of a control circuit including multiple control options, such as infrared communication, Bluetooth, WiFi, LiFi, and optical switching picture. Fig. 24 shows the programming flow control of the beam control preset; Fig. 25 shows the beam control state switching flow control in use; Fig. 26 is a variant embodiment of Fig. 23, wherein the LC beam control device is controlled by the light source and the light source has communication circuitry for receiving user commands to control the LC beam steering means; and Fig. 27 is a variant embodiment of Fig. 26 wherein the LC beam steering means is controlled by the intensity modulation of the light source control, and the light source has a communication circuit for receiving user commands to control the LC beam steering device, wherein the LC beam steering device is powered by an electrical connector of the light source.

The operation of the proposed device can be better understood with the help of the detailed description below.

The control element that transmits the light beam is described by the inventors herein, published in International Application WO2016/026055 on February 25, 2016, and disclosed in the corresponding US Pre-Grant Publication 2017/0218686, which is incorporated in its entirety. Incorporated herein by reference. This PDLC film provides electrically controllable light scattering. For example, Figure 4A shows similarly sized chaotically oriented LC domains scattering light in the ground state, where Figure 4B shows similarly sized LC domains redirected by an applied spatially uniform electric field to allow light transmission using a polymer The index of refraction matched between the normal index of refraction of the matrix and the LC material.

It has been determined that Figures 4A and 4B are highly schematic in order to simplify the presentation of the operational concepts of the solutions presented here. According to the proposed solution, a random distribution of refractive index control center size, commonly referred to in this paper as polydispersity, is employed to provide variable dispersion control in lighting devices, i.e. architectural lighting sources.

According to one embodiment of the proposed solution, Figure 5A is a microscope image showing the abundant presence of multiple LC droplets of different sizes (showing the polydisperse character of the composite) well dispersed on the polymer matrix. For example, prior to photopolymerization, such materials typically contain 25% LC, 74% monomer and 1% photoinitiator composite.

Figure 5B is a microscope image showing the relatively "sparse" presence (spaced apart) of LC droplets with low dispersity of dimensions sparsely located (dispersed) throughout the polymer matrix.

Figure 6A is a graph showing the characterization results versus voltage showing the change in transmission intensity obtained using a commercially available PDLC privacy film with the microstructure shown in Figure 5A in front of a CREE liquid crystal source. As shown in Figure 7 (for a 1/10 second exposure), in the ground state (0V when no drive signal is applied), the PDLC film is sub-translucent, but not opaque (see Figure 4A). With the gradual application of a voltage-controlled drive signal (RMS with a fixed frequency), the PDLC film gradually became more translucent and more transparent at a high voltage of 50V. Figure 8A shows a 1/15 second exposure through the beam intensity pattern projected through the LEDs of the PDLC film of Figure 5A driven at 10V AC, while Figure 8B shows a 1/60 second exposure through at 50V AC The beam intensity pattern projected by an LED driven by the same PDLC film. For all intents and purposes, although PDLC films can operate safely at RMS voltages around 120V AC without degradation, the light transmittance increases asymptotically, essentially reaching a plateau above 80V AC. Figure 8C shows a 1/60 second exposure beam intensity pattern projected by an LED through the same PDLC film driven at 120V AC. As can be observed from a visual comparison between Figure 1 and Figure 8C, a portion of the incident beam intensity is lost (for the same 1/60 second exposure). The measured projected illuminance corresponding to the CREE LED of Figure 1 without the PDLC element is shown in the graph of Figure 6A for comparison. Exposure time (intensity fixation) was different in each graph so that the visual representation of the graphs avoids white saturation (intensity burning).

The measured light scattering properties are illustrated graphically in Figure 9. Referring to Figure 7, which corresponds to a structure in which the PDLC film of Figure 5A scatters light at the maximum level, shown in Figure 9 as the largest outer ellipse. A stepwise increase in the RMS voltage level of the drive signal applied to the PDLC film reduces light scattering and thus light divergence (Fig. 8C) to almost reduce to its original value without the PDLC film (Fig. 1) (however resulting in Smaller intensity as in Fig. 6A).

From a technical point of view, Fig. 9 depicts the optical CREE LED source of Fig. 1 emitting light through the PDLC film of Fig. 5A under different driving conditions of the PDLC element, its intensity is measured at different angular positions, thus obtaining the extension A (standard) normalized polar plot of the angles. In the ground state, with 0 Vrms applied to the PDLC film, the projected beam exhibits the broadest light intensity distribution (Fig. 7), corresponding to the largest outer ellipse representing the 48.8°F WHM. Applying a drive signal of 10 Vrms on the PDLC film reduced the beam spread to the second ellipse corresponding to the 28.0°F WHM. Increasing the drive signal voltage applied to the PDLC film to 20Vrms further reduced beam spread to 17.3°F WHM. Further increasing the drive signal voltage applied to the PDLC film of 50Vrms reduces the beam spread to 16.2°F WHM, the corresponding graph with a measured spread of 15.6°F WHM corresponding to the inherent dispersion of the spot beam of the LED light source (without the PDLC film) There is little difference in the graph of the angle. It can be seen that the PDLC orientation at 50 Vrms (Fig. 4B) is nearly saturated and almost as transparent as possible (see Fig. 6A). These optical spreading results represent a significant overall improvement, providing an increase in the maximum divergence angle, greater than 33° (or a broadening factor >3; measured by the ratio of the divergence angle at the applied maximum voltage to the ground state divergence angle), which is Very inspiring, getting a fairly large angle of expansion with fairly good optical quality.

In contrast, Figure 6B is a graph showing measured light transmission versus applied voltage for the device depicted in Figure 5B. Due to insufficient polydispersity of the material, the transport change is abrupt and occurs within a relatively narrow range of control voltage values. Furthermore, hysteresis loops were observed, which may have some applications, however for general lighting applications, hysteresis introduces complexity in the control of such devices.

It is worth noting the limitation of the acceptance angle of the detector used to obtain the presented results; if the acceptance angle of the detector is larger, a wider beam dispersion or a gentler drop in beam intensity will be measured (both considered a better measurement). The low acceptance angle of the detector is believed to be responsible for the lower measurement of light transmission through the PDLC film, as the asymptotic intensity values depicted in Figure 6A compared to the measured intensity of the LED light source without the PDLC film ( about 82% transmission efficiency). It is believed that better light integration including light propagating at (shallower) wider angles (light scattered by the PDLC film at higher scattering angles) will show a measured transmittance close to about 90%, as the PDLC film expects Does not absorb much light at high scattering angles.

One of the many advantages of using the proposed combination of PDLC film elements and LED light sources is the cost efficiency of manufacture, as PDLC films can have lower production costs than arrays of LC beam shaping devices. Manufacturing tolerances for PDLC films for controlled LED beam dispersion applications can be reduced compared to the manufacturing tolerances required for PDLC lens elements or PDLC privacy panes. The lower manufacturing tolerances, if random, can cause beam dispersion, which is desirable in the case of point-beam LED light sources. Wafer-level fabrication of planar uniform transparent electrode layers is superior to electrode strips that require precise deposition of tens of micrometers wide. ("Planarly uniform" may include uniformly sparsely deposited flat electrode layers).

According to one embodiment of the proposed solution, Figure 10 shows an actively controlled PDLC film driven directly from mains power, which is used directly and exclusively in front of a spot beam LED source to provide variable dispersion control. When the main switch is closed, the LED light source produces an incident beam that provides a spot beam. The divergence control switch controls beam expansion, which selects a widened output beam when the switch is open (Fig. 7), or a spot beam output beam when the switch is closed (Fig. 8C). It will be appreciated that Figure 10 is highly schematic, eg not showing the electrical components of the current limiter, which can limit the current delivered to the PDLC film. Preferably, the PDLC film includes a transparent planar uniform electrode layer. The main power supply can be one of the 50Hz and 60Hz 120/110V AC power cords. In the implementation of this embodiment according to the proposed solution shown in Figure 10 a PDLC film is used, preferably a PDLC film connected between live and ground is driven full cycle (see Figure 6A).

In another embodiment according to the proposed solution, an actively controlled PDLC film, via pulse width modulation (PWM) from a power driver, is used directly and only in front of spot beam LED sources to provide variable dispersion control . While the details of the PWM controller are not provided herein, those skilled in the art will understand that such a PWM controller, essentially replacing CTRL in the schematic circuit, may include a thyristor type dimmer or Wave counter signal generator in series at high frequency. In one implementation according to the proposed scheme, the preset PWM drive duty cycle is selected by looping through the loop mains. In another implementation according to the proposed solution, the selector switch can be incorporated into the panel of the luminaire, eg a selector ring.

In another implementation in accordance with the first embodiment shown in Figure 11, control may be achieved by a selector (CTRL) configured to select among a plurality of discrete presets: disconnecting the PDLC film from the power line to To provide the widest output beam (Fig. 7), connect the PDLC film in parallel to the power supply to essentially allow the LED spot beam to pass (Fig. 8C), connect the PDLC film to the power supply through a rectifier, which essentially achieves half the value of work The widest output beam was converted to a spot beam during the period, and the PDLC film was connected between the ground and live wires, which substantially reduced the applied voltage by half (Fig. 8B). According to one embodiment of the proposed solution, the preset value can be selected by looping through which the main power supply loops. According to another implementation of the proposed solution, the selector switch can be incorporated into the panel of the luminaire, eg a selector ring.

Figure 12 shows, according to another embodiment of the proposed solution, a pair of preferably dissimilar PDLC films electrically connected in series, driven eg directly from a 120/110V or 240/220V AC power supply. Without limiting the invention, the dissimilarity between PDLC films may be the thickness of the LC layer or the polydispersity of the LC droplets or the difference in the chirality of the LC material. Selective switches can be electrically connected between the PDLC films to achieve a variety of output beams. When the selector is in the electrically floating position, the full supply voltage is applied full cycle to a pair of series-connected PDLC films, and each PDLC film imparts a dispersion effect to the incident beam. Due to the dissimilarity between PDLC films, the sequence of incident beams passing through the PDLC films can provide different output beams. The selector can be configured to electrically short one PDLC film, with the substantially shorted PDLC film providing the corresponding widest output beam; while the full supply voltage is applied to the other PDLC film, which provides substantially little beam divergence. Due to the dissimilarity between PDLC films, the dispersion of the output beam can be different according to the ordering of the PDLC films. When the selector is connected to ground, substantially half of the power supply voltage is applied to each PDLC film. When the control selector is connected to one of the two oppositely connected rectifiers, a corresponding one of the PDLC films can be grounded during one half cycle, while during the other half cycle, both PDLC films are connected to the mains. Since the PDLC films are dissimilar, the output beam can provide different lighting conditions according to the choice of its rectifier polarity. According to one embodiment of the proposed solution, the preset value can be selected by looping through which the main power supply loops. According to another implementation of the proposed solution, the selector switch can be incorporated into the panel of the luminaire, eg a selector ring.

Figure 13 shows another embodiment according to the proposed solution, a pair of preferably similar PDLC films electrically connected in series, each PDLC film providing dispersion into the spot beam of a corresponding spot beam LED light source, e.g. Directly driven by 120/110V AC. Each LED and PDLC film pair is configured to be oriented to project a corresponding output beam in a different direction to provide projections that do not necessarily overlap. Without limiting the present invention, the directional projection of the light beam can be achieved by, for example, arranging a predetermined stopper on at least one gimbal mechanism (not shown). Such combinations can take input voltages available in architectural and industrial lighting applications, while still being configured to project uniform illumination into differently oriented output beams.

The advantage of using such thin films of PSLC, as opposed to PDLC films, is the very limited presence of a polymer known to be relatively sensitive to UV light. Another advantage is the relatively low voltage required to drive PSLC elements.

According to another embodiment of the solution proposed by the present invention, Figure 14 shows the control of the polydispersity of LC agglomerates in PSLC composites, typically containing 95% LC, 4% monomer, 1% light A mechanism for initiating material complexes, set before photopolymerization, as in V.V.PRESNYAKOV, T.V.GALSTIAN, "Light Polarizer Based on Anisotropic Nematic Gel with Electrically Controlled Anisotropy of Scattering" "Electrically Controlled Anisotropy Based on Anisotropic Nematic Gels" Anisotropic Scattered Light Polarizers", MC & LC, Molecular Crystals and Liquid Crystals, Volume 413, 2004-issue 1, which is hereby incorporated by reference in its entirety. The PSLC film observed in Fig. 14a) is between crossed polarizers. In Fig. 14b), the PSLC film is observed through a polarizer, which is parallel to the original orientation of the (ground state) LC molecules, in Fig. 14c), the PSLC film is observed through a polarizer, which is parallel to the (ground state) ) The original orientation of the LC molecules is vertical. It can be determined that the observation of the PSLC film through the polarizer is for illustration purposes only; it is recommended to use the PSLC film to the LED light source without any such polarizer.

Figure 15 shows, according to the solution proposed by the present invention, in another embodiment of controlling the light transmission mechanism, another polydispersity PSLC layer is used. In this case, very strong scattering and large beam expansion are achieved, mainly corresponding to one polarization mode of the light (almost a factor of 300). If desired, two such PSLC layers can be used, the optical axes of their ground states being perpendicular to each other (both perpendicular to the original incident propagation direction of the light). This bilayer device can control the divergence of unpolarized light.

Figure 16 shows that in one embodiment of the controlled light transport mechanism, according to the proposed solution, a nanoparticle dispersed LC layer is used as described in Paul J. Ackerman, Jao van de Lagemaat, & Ivan I. Smalyukh , "Self-assembly and electrostriction of arrays and chains of hopfion particles in chiral liquid crystals", "Self-assembly and electrostriction of hopfion particles in chiral liquid crystals", in NATURE COMMUNICATIONS | DOI: 10.1038/ncomms7012, 2015 , the entire contents of which are incorporated herein by reference. Elastic self-assembly and patterning of topological particles that provide scattering/dispersion centers are shown. Figure 16A is an optical micrograph showing hexagonal ordering in a densely packed toron array with large area grains separated by grain boundaries. Figures 16B to 16D show polarized optical micrographs depicting the transition from (Figure 16B) isotropic repulsive interactions mediating the formation of hexagonal arrays to (Figure 16C) weakly anisotropic attractive interactions resulting in relatively Small periodic topological grain crystallites, and (Fig. 16D) highly anisotropic interactions lead to voltage-controlled transitions of toron-cable dipoles. The red arrows in Figure 16D indicate the direction of the far field c and the green arrows depict the orientation of the toron-cable dipole. In this case, a change in voltage can achieve very strong scattering, and a large beam broadening. If desired, two such PSLC layers can be used, the optical axes of their ground states being perpendicular to each other (both perpendicular to the original incident propagation direction of the light). This bilayer device can control the divergence of unpolarized light.

Fig. 17 schematically shows, according to yet another embodiment of the solution proposed by the present invention, a control system of light transmission divergence angle and intensity is realized by using the above-mentioned LC device. It should be understood that either lens or reflective optics (or a combination of both) may be used to provide the collimated spot beam from the light source.

With appropriate changes, the proposed solution provides a light source module with controllable beam shape, including a controllable beam control module and a light source module providing said initial beam, which can be configured to adapt the light source module to Light sources to scanners, camera flashes, architectural, automotive or industrial lighting installations.

It can be ascertained that nothing in this description is intended to exclude the inclusion of at least one LED light source, with a dynamically controlled LC beam shaping device element (with a plurality of electrodes) and a dynamically controlled polydisperse LC film element. In such an embodiment, control of the LC beam shaping device may be integrated with the LED power conversion components, while control of the parallel polydisperse LC film elements may be provided by a power source.

In one embodiment shown in Figures 18 and 19A, the beam steering device for liquid crystal has a circular light-passing hole for mounting to a light source having a circular light-passing hole. It should be understood that non-circular optical vias may be provided. The device includes a mounting frame for holding photovoltaic supports, such as a circuit board ring, and substrates for liquid crystal cells. It should be understood that the optoelectronic elements may be supported by the LC element substrate, rather than a separate substrate, as is the case with circuit boards. Although the device can be attached directly to the light through-hole lens or window of a spot beam bulb (LED type, fluorescent or incandescent) as shown, the device can be attached to a light source fixture separate from the light emitting component. In addition, the shape of the LC beam steering device and the light-passing aperture may be different from circular. Some LED spot beam light sources provide multiple LED emitters arranged with lenses for orienting the spot beam from each emitter, and in this case the LC beam steering device may have a single light aperture covering all such A spot beam, or a number of light-passing holes, corresponds to each spot beam. Some other LED light sources, such as arrays of LED devices commonly used provide a linear light source, and LC beam steering and light apertures can be adapted to this geometry.

The adjustable rotational position mount shown in Figure 19A is optional, however, it is advantageous when the LC device is rotationally dependent to be able to adjust the rotational position of a spot beam, such as in a given Beam steering or expansion in the direction. In this case, when the user wishes to widen or turn (stretch) the light beam in a given direction, the mounting can be used to set the direction without additional (eg manual) adjustment of the rotational position of the light source, such as By adjusting the socket connection.

The structure or type of LC beam steering device may vary. In Figure 19A, a type of LC beam expanding device is schematically shown, which has two LC cells and is capable of expanding unpolarized light in both directions at the same time.

Other LC devices as shown in Figure 19B, such as polymer dispersed liquid crystal cells, can be used to controllably introduce divergence into the beam, where a single layer will act on both polarization directions and produce a substantially uniform divergence, so it is The direction of rotation is irrelevant. In a PDLC device, the LC material fills the pockets of the polymer matrix material, and the LC material is in a disordered arrangement in the ground state. This causes dispersion of light. When the electrodes are driven, the electric field orients the liquid crystal material and this reduces or eliminates light scattering. Voltages between 25V and 125V corresponding to the thickness of the PDLC material are typically used. Because the power required is quite low, photovoltaic arrays driven by visible light sources can provide the required voltage and power.

On the polymer stabilized liquid crystal cell, a polymer "network" with spatially varying density is formed in the LC cell. The LC material can use an alignment layer to form an ordered ground state, and a low voltage is applied to the planar transparent electrode on the optical via, which can be used to transform the LC material from a transparent ground state to a spatially varying excited state. Such NLC cells act on one polarization direction of light, so two cells are used to modulate two orthogonal polarization directions.

Other LC devices may require layers of liquid crystal material to control light in a single polarization direction in a single direction, and thus these devices may include four layers of liquid crystal to control two directions and two polarization directions.

The type of liquid crystal beam expander of Figure 19A is better shown in Figures 20A, 20B and 20C. Figure 20A shows a basic cell structure comprising a substrate 12 with a gap filled with LC 20, which is typically oriented in the ground state by rubbing the alignment layer 18 into a planar orientation, ie with a small pretilt angle relative to the substrate Aligned liquid crystal molecules. Electrodes 14A and 14B are patterned (interdigitated) extending in the page to form parallel strip electrodes. The effect of applying an electric field is to spatially modulate the orientation of the liquid crystal molecules, resulting in a substantially cylindrical lens, such as a change in the refractive index due to the change in orientation. The light modulation of the substantially cylindrical lens acts substantially only in one polarization direction, and the light is substantially broadened in a plane perpendicular to the electrode lines.

As shown in Figure 20B, four such cells can be configured to modulate light in two polarizations in two directions. The patterned electrode structure on one of the substrates in the device of Fig. 19 is shown schematically in Fig. 20C. Figure 20D shows the optical power distribution of the broadened beam at different voltages along the desired direction. It also shows that the original (ground state of the LC device) beam transforms into a flat-top beam.

Figure 21A is an image of two laser beams, each passing through an LC beam expander similar to the one shown in Figures 20A to 20C, with the LC device in its ground state. Figure 21B shows the image of the two spot beams when the LC device is driven, and the LC device is aligned and oriented, while Figure 21C shows the situation when the LC device is misaligned. It can be seen that while the LC device provides a spatial structure to modulate the light, the orientation is important to control the combined behavior of the beams. Rotationally positionable mounts are therefore important for such LC devices. As mentioned above, some LC devices, such as PDLC and polymer-stabilized LC devices, can be used to modulate light and do not provide direction-specific modulation, so the direction is not critical.

Fig. 22 is a schematic illustration of a side view of a strip or ring circuit board as in cross-section of Fig. 19, including photovoltaic elements mounted on one side for harvesting energy from a light source. The same loop circuit may also include a driver ASIC, antenna, or other electronic circuit elements necessary for dynamic control of the LC device. The LC cells shown in Figures 20A to 20C can be driven with a voltage of about 15V to 30V. PDLC devices are typically driven using voltages from 50V to 100V. A photovoltaic cell typically produces an open circuit between 1V and 2V. Since most liquid crystal devices consume very little power (eg, tens of milliwatts), small photovoltaic elements can be connected in series to suitably generate low power, high voltages for driving such LC devices. By arranging typically opaque photovoltaics and supports (eg circuit boards) around the perimeter of the beam steering device, only a small fraction of the beam is lost to the frame of the LC beam steering device (eg, the ring described above may have a width of about 0.5mm) .

Figure 23 is a schematic block diagram of the electronics of the LC beam steering apparatus according to one embodiment including many different options. For programming and/or controlling the beam control state of the LC device, three different types of interaction interfaces are shown, namely, infrared (IR) interface, Bluetooth interface and wireless interface. IR interfaces are inexpensive and may include IR emitters and receivers mounted on the output side of the frame of the device. A programmed remote control device may have an input key configured to signal the controller to cause a desired change in the beam control state of the LC device. A key can be used to signal that the selected state is set to a preset and thus stored in non-volatile memory. The button can directly specify the preset position or sequence, or can be specified in conjunction with different inputs. The programming process is shown in Figure 24.

Alternatively, RF wireless interfaces, such as Bluetooth or wireless networking, can be used. Because such interfaces are typically common in computers (including mobile computing and communication devices), the programming means may execute selected presets with or without the controller to display beam modulation to the user so that the Set the state to be stored in non-volatile memory to confirm the selection. This RF wireless interface can also directly control the beam modulation state without relying on the presets stored in the memory of the LC beam control device.

Although more complex in method, the control of the LC beam modulation device can be accomplished by using different interfaces. One or more light sensors disposed on the frame can be used to detect beam patterns attached to the frame, which can be interpreted as control or programming commands. Images of the same beam patterns can be captured with cameras mounted on the frame and interpreted as control or programming commands. Such sensor elements can also be used for programmed "self-tuning" functions of LC beam steering devices. For example, the presence of a person can be detected and the corresponding expansion angle can be obtained automatically according to a pre-programmed design.

The Bluetooth transceiver module, which is battery powered, can be used as a remote control or as a wall mounted controller for controlling the state of the LC device, eg using it to change from one preset to the next.

Another option is to switch the conventional power supply of the light source by switching ON/OFF of the light source to control the beam control state of the LC device. Using this option, when the light source is first turned on, the user can configure the LC beam steering to restore the previously selected state. This selected state may correspond to a spot beam (unmodulated), a beam steering state and/or a beam expanded state. However, if only a static configuration is desired, static optics can be used. Advantageously, the LC beam steering device can be configured to have other states, and a simple OFF/ON optical switch that causes the emitted light to switch OFF and back again when detected by the ON/OFF detection circuit ON. The output of this detection circuit is provided to the controller. The controller can be a dedicated circuit executing code in memory, an FPGA or a processor. The controller responds to the OFF/ON transition to cause the LC drive signal generator to change to parameters according to the next preset drive signal stored in the non-volatile memory.

The circuit of Figure 23 shows the energy from the PV element charging the capacitor to filter any intensity fluctuations. A portion of the PV elements may provide low voltage power supplies for circuits and/or controllers and other electronic processors, while high voltages are used for electronic components in the LC drive signal generator for supplying drive signals to the LC electrodes. As shown, low voltage regulators can also be used to convert high voltages to low voltages for supply to components.

Fig. 25 is an example of a sequence involved in ON/OFF switching control of the LC light beam control device. When the light source is powered on for the first time, power is supplied to the controller, and the controller retrieves a default preset from memory, so that the drive signal generator controls the LC device according to the preset preset. In the non-modulation preset of a PDLC device, when the light is turned on, it always scatters or is initially broadened and then becomes a spot beam, because in a PDLC device the ground state is the scattered and fully actuated state is transparent. In many other LC devices, where the ground state is unmodulated, a spot beam will initially appear until any desired modulation is applied. As shown in Figure 25, if the user toggles the optical switch, the detector circuit detects this rapid ON-OFF-ON change and signals the controller accordingly. Then, the controller controls the LC drive signal generator for executing the next preset state stored in the non-volatile memory. For example, there could be a device for beam divergence or expansion, producing both spot and sheet beam states. However, some LC devices may provide other modulations, and their states may be changed, resulting in the functionality of the LC device.

Alternatively, as schematically shown in Figure 26, the control circuit may be integrated with the light source, the intensity modulation of which is used to control the circuit within the LC beam steering device. The light source data communication may include a powerline data interface, such as an X10 interface, a Bluetooth interface or a wireless WiFi interface, and the data transmitted to the light source may be used to control the continuous intensity of the light source. The transmission of data can be decoded by a controller that generates an intensity modulation signal for the driver circuit of the light source such that the modulation of the intensity of the light source can be detected by the PV element of the LC device, decoded in a decoder, and then Used by the LC device controller to control the LC drive signal generator.

In the embodiment of Figure 26, the light source is provided with communication capabilities for being able to control the LC device. It would be advantageous if the building also provided LiFi. For example, a LiFi interface may include its own IR source and detectors that use IR light to communicate with other LiFi devices. The LiFi interface can be connected to wireless data infrastructure using wired or non-LiFi connections, such as powerline data interfaces or Bluetooth or wireless network relays. The IR transmitter and receiver of the LiFi interface can utilize the same optical path as the light source, eg, the same reflector or focusing optics. In addition, the IR transmitter and receiver of the LiFi interface can use the LC device to adjust the area in which the LiFi interface will communicate. The LC device can be used to adjust such areas as needed. The LiFi interface can be used, in turn, to communicate control commands with the LC device controller to improve LiFi performance.

Figure 27 shows a variant embodiment of Figure 26 in which power for the LC beam steering device is provided through electrical connectors connected to the light source. In this embodiment, the voltage of the power line can be delivered to the LC beam steering device if voltage is required.

Although the present invention has been shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the invention as defined by the appended claims spirit and scope.

Claims (15)

A liquid crystal beam steering device comprising: a light source configured to provide a beam of light; a liquid crystal spatial light modulator having a control electrode arranged to receive the beam of light from the light source; a photovoltaic array arranged a periphery to receive the light beam of the light from the light source; a drive signal circuit connected to the photovoltaic array and outputting a drive signal to the control electrode in response to an input control signal; a controller responsive to the A command signal, and outputting the input control signal; and a mounting frame including a central light-passing hole, wherein the liquid crystal spatial light modulator includes a substrate connected to the mounting frame and at the center of the mounting frame The perimeter of the through hole supports the photovoltaic array arranged to intercept the perimeter of the light beam of the light source. The apparatus of claim 1, wherein the mounting frame removably secures the liquid crystal spatial light modulator to the light source. The device of claim 2, wherein the liquid crystal spatial light modulator and the mounting frame are circular. The apparatus of claim 3, wherein the photovoltaic array is arranged on a circuit board ring. The device of claim 4, wherein the photovoltaic array is arranged on the light source side of the liquid crystal spatial light modulator. The apparatus of any one of claims 1 to 5, further comprising a light source intensity modulation detector configured to provide the command signal based on modulation of the light source. The apparatus of claim 6, wherein the light source intensity modulation detector is responsive to light source OFF/ON switching. The apparatus of claim 6, wherein the light source intensity modulation detector demodulates the intensity modulation of the light source. The apparatus of claim 6, further comprising a wireless data interface connected to the controller for providing the command signal. A liquid crystal beam steering device comprising: a light source configured to provide a beam of light; a liquid crystal spatial light modulator having a control electrode arranged to receive the beam of light from the light source; a photovoltaic array arranged to receive the light from the light source; a drive signal circuit connected to the photovoltaic array and outputting a drive signal to the control electrode in response to an input control signal; a light source intensity modulation detector configured to be based on The modulation of the light source provides a command signal; a controller that responds to the command signal and outputs the input control signal; and a mounting frame that includes a central light through hole, wherein the liquid crystal spatial light modulator including a substrate connected to the mounting frame and supporting the photovoltaic array at the perimeter of the central light through hole, the photovoltaic array being arranged to intercept the light The perimeter of the source's beam. The apparatus of claim 10, wherein the light source intensity modulation detector is responsive to light source OFF/ON switching. The apparatus of claim 10, wherein the light source intensity modulation detector demodulates the intensity modulation of the light source. The apparatus of claim 10, 11 or 12, further comprising a mounting frame for removably securing the liquid crystal spatial light modulator to a light source, the mounting frame including an electrical connector, It is used to receive electrical energy from the light source. A liquid crystal beam steering device comprising: a light source configured to provide a beam of light; a liquid crystal spatial light modulator having a control electrode arranged to receive the beam of light from the light source; a photovoltaic array arranged a perimeter for receiving said beam of said light from said light source; and a rotatable mounting frame including a central light through hole for securing said liquid crystal spatial light modulator to a light source while allowing said liquid crystal spatial light Rotational orientation of a light modulator; wherein the liquid crystal spatial light modulator includes a substrate connected to the rotatable mounting frame and supporting the photovoltaic array at the periphery of the central light-passing hole, the The photovoltaic array is arranged to intercept the periphery of the light beam of the light source. The device of claim 14, wherein the liquid crystal spatial light modulator and the mounting frame are circular.

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