具体实施方式：
[0026]It is noted that the drawings of the disclosure are not to scale. The drawings are intended to depict only example aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering may represent like elements.
DETAILED DESCRIPTION
[0027]High touch surfaces may be commonly inhabited by harmful microorganisms due to the nature of their use by humans or other animals. Microorganisms may transfer from, e.g., human to human, through contact of the same high touch surfaces and can cause illness to the users. Harmful bacteria such as Escherichia coli (E. coli), Salmonella, Methicillin-resistant Staphylococcus Aureus (MRSA), and Clostridium Difficile may be found on many surfaces, which may increase the chance of a user becoming sick or transmitting the bacteria. For example, there are numerous cases of hospital acquired bacterial infections. Healthcare facilities are one or many facilities at risk for causing or spreading illness. Athletic facilities/gyms, public transportation vehicles, food preparation or production plants, hotels, offices, etc., are all at risk for hosting the contraction of bacterial related illnesses by their inhabitants.
[0028]High touch surfaces, such as handles, may be disinfected in a number of ways, such as cleaning with disinfecting, chemical cleaners. Chemical cleaners may only provide intermittent disinfection, and may allow harmful microorganisms to build up between cleanings. Because humans may contact a surface at any time, continuous disinfection may be advantageous.
[0029]In some examples, antimicrobial coatings such as silver, copper or zinc, may be used to disinfect. These coatings may be applied directly to surfaces, or may be provided in high touch surfaces (e.g., handles). These coatings, however, may wear off or may require replenishing. They may also be messy and/or unsafe for human contact. Antimicrobial coatings may also damage surfaces to which they are applied.
[0030]In some examples, high touch surfaces may be internally illuminated. Often, internal illuminated surfaces may be prone to dead spots (e.g., areas with inconsistent or no illumination) due to various reasons such as spacing of centrally located light emitters, edge lighting decreasing over lengths of surfaces, etc. Examples of the present disclosure provide expansive light directing elements to redirect light from a light source to consistently a illuminate a surface with a similar intensity and irradiance. In examples disclosed herein, internal illuminations may be configured with disinfecting properties. In contrast to devices that transmit ultraviolet (UV) light through a high touch surface for disinfection, which may be harmful to humans and so the light must be off during human use, examples disclosed herein provide non-harmful disinfecting internal illumination to initiate inactivation of bacteria on external surfaces. In such examples, the internal lighting may be continuously illuminated to constantly inactivate bacteria while being safe for human exposure.
[0031]The example light directing elements may include an elongated body having a first end, a second end, and an exterior surface. The example light directing elements may be transparent or translucent to permit transmission of light therethrough. The example light directing elements may be solid and/or cylindrical, and may be used as high touch surfaces (e.g., handles). In some examples, the light directing elements may have various cross sections other than circular (e.g., from a cylinder) such as, for example, a square cross section, a polynomial cross section, a D-shaped cross section, an ovular cross section, etc. Further, the example light directing elements may be internally illuminated with disinfecting light. The light may be any color desired. In contrast to conventional systems that employ dangerous (UV) light, light directing elements may direct light through the exterior surface, wherein at least a portion of the light exiting the exterior surface has a wavelength in a range of approximately 380 to approximately 420 nanometers (nm). In some examples, the light directing elements may be configured such that a portion of light exiting the exterior surfaces of the light directing elements has a wavelength of 405 nm. Light having a wavelength in the range of approximately 380 to approximately 420 nm may inactivate microorganisms such as, for example, Escherichia coli (E. coli), Salmonella, Methicillin-resistant Staphylococcus Aureus (MRSA), Clostridium Difficile, and a wide variety of yeasts and/or fungi. The disinfecting light may also include other wavelengths of light to create other colors such as, for example, white light.
[0032]The example light directing elements may enable the direction and distribution of light to their exterior surfaces with sufficient intensity and/or irradiance to consistently illuminate the light directing element. In examples utilizing disinfecting light, the light should have sufficient intensity and/or irradiance to disinfect the exterior surface (e.g., achieving continual and even disinfection).
[0033]To this end, an example light directing element may include a diffuser including at least one light reflective element arranged within the elongated body to create an axially, enlarging reflective arrangement to progressively redirect light toward the exterior surface as the light passes axially through the elongated body. A light emitter may be operably coupled to the elongated body for emitting light axially through the elongated body. The diffuser may provide a mechanism to direct and distribute lighting in a controlled, consistent, and uniform manner to an exterior surface of the elongated body.
[0034]Referring to the drawings, FIGS. 1A, 1B, and 2 show perspective views of an example light directing element 100 (hereinafter “element 100”). Element 100 may include an elongated body 110 having a first end 112, a second end 114, and an exterior surface 116. Elongated body 110 may be transparent or translucent to permit transmission of light 120 therethrough (e.g., from one end to the other end, out the exterior surface, etc.). Light 120 may travel through elongated body 110 regardless of where light 120 originates.
[0035]Elongated body 110 may be used as any internally illuminated element, such as a lighting element, but may further be utilized as a high touch surface, such as a handle. A “high touch” surface may be an outside part or uppermost layer of something (e.g., body 110) that may be (but not necessarily) exposed to contact (e.g., by humans or other animals) that transfers or otherwise creates microorganisms on that part or layer. Element 100 may be utilized as a handle frequently grasped by users, e.g., a door handle, refrigerator handle, etc.
[0036]Elongated body 110 may also include an exterior surface 116 configured to be illuminated, grasped, and/or disinfected. Exterior surface 116 may be is textured or otherwise diffuse and may replace a preexisting high touch surface as the outside part or layer of a structure. A portion of elongated body 110 (not shown) through which the transmission of light 120 may not be necessary (e.g., such as those portions covered by end caps or transfer caps shown and described with reference to FIGS. 22-23) may not need to be transparent or translucent. Elongated body 110 can be made of any transparent or translucent material, e.g., clear acrylic, diffuse polycarbonate plastic, glass, any combination thereof, etc. “Transparent” or “translucent” may indicate any level of light transmission short of opaque. As shown in FIG. 1A, elongated body 100 may be a solid cylindrical body. However, elongated body 110 may be other shapes that allow for the transmission of light 120 therethrough and to external surface 116, e.g., cylindrical but with one or more planar chords therein, hexagonal, etc.
[0037]Element 100 may also include a diffuser 130 including at least one light reflective element 132. In some examples, the diffuser 130 may comprise a plurality of light reflective elements 132 (shown as dots in FIGS. 1 and 2) arranged within elongated body 110 to collectively create at least one axially, enlarging reflective array 134 to progressively redirect light 120 toward exterior surface 116 as light 120 passes axially through elongated body 110. In some examples, the diffuser 130 may be a solid conical structure such as, for example, diffuser 1100 illustrated in FIG. 11. Of course, other shapes may be used such as, for example, a truncated cone, a trapezoidal prism, a paraboloid, a half sphere, a pyramid, other known geometric shapes, and/or any combination thereof.
[0038]The plurality of light reflective elements 132 may be arranged within elongated body 110 to redirect light 120 toward exterior surface 116, creating exiting light 126. In some examples, exiting light 126 is substantially uniform and/or comprises a consistent irradiance across a surface area of exterior surface 116. In one example, exiting light 126 may have an irradiance of at least 0.01-0.02 milliWatts per square centimeter (mW/cm2) across exterior surface 116. One or more of the plurality of light reflecting elements 132 may be at least partially reflective so as to redirect light from an incident angle to a reflected angle, which may direct light 120 to exterior surface 116. One or more of the plurality of light reflecting elements 132 may include a planar, magnetic body to allow for proper positioning thereof during manufacture, which will be described in detail herein. One or more of the plurality of light reflective elements 132 may have a magnetic field configured to enable magnetic positioning of the one or more of the plurality of light reflective elements 132 in a desired location within the elongated body 110, such as, e.g., in groups and axially symmetrical about centerline C, helically as shown in FIG. 1B, and/or other configurations. One or more of the plurality of light reflecting elements 132 may be made of, for example, ferromagnetic material, magnetic metal, or include such material. The size of light reflecting elements 132 may vary to better provide uniform and/or consistent illumination across the exterior surface 116. In some examples, one or more of the plurality of light reflecting elements 132 may have a surface area of less than approximately 4 square millimeters (4 mm2).
[0039]FIGS. 1A-1B illustrate an example single axially enlarging reflective array 134. As illustrated in FIGS. 1A-1B, the example axially enlarging reflective array 134 may face the first end 112 of the elongated body 110 and may redirect light 120 entering first end 112. FIG. 2 illustrates an example of the elongated body 110 comprising a pair of axially enlarging reflective arrays 134A, 134B. Array 134A may face the first end 112 of the elongated body 110 and may redirect light 120 entering the first end 122. Array 134B may face the second end 114 of elongated body 110 and may redirect light 120 entering the second end 114. An array may face a direction such that reflective portions of reflective elements 132 are positioned to have light from that direction strike them and be redirected. In some examples, the array(s) 134 may be conical in arrangement, such that the apex of the conical arrangement may be closest to the end 112 and/or 114 which it faces. The density and/or position of one or more of the plurality of light reflecting elements 132 may vary axially and/or radially, such that a collimated beam of light 120 oriented parallel to centerline C entering an end 112, 114 of element 100 at an axial position may be output at a correlated radial position. The sum effect of the numerous small reflective elements 132 and exterior surface 116 boundary may create an optic that receives light 120 input on one and/or both ends, and advantageously emits exiting light 126 uniformly over at least a portion of exterior surface 116.
[0040]As shown in FIGS. 1A and 2, and in an enlarged cross-sectional view of FIG. 3, each axially enlarging reflective array 134 may include one or more groups of light reflective elements 132, which may collectively form a series of increasing sized reflective structures relative to centerline C. In FIGS. 1A and 2, the reflective structures may be circular, e.g., reflective elements 132 may be arranged serially in circles. However, as shown in FIG. 4, groups may be arranged as increasing radius arcs, which may not create exiting light 126 entirely about exterior surface 116, but only in selected arcuate sections thereof. Any angle of arc may be employed, e.g., anywhere between 1° and 360°. The example reflective elements may be arranged in a generally conical arrangement. However, as shown in the perspective view of FIG. 5, they may be alternatively arranged in a truncated or frusto-conical arrangement, e.g., conical with a cut off end. Furthermore, the plurality of reflective elements 132 may be arranged in a helical pattern (e.g., FIG. 1B) or may form a solid conical structure (e.g., FIGS. 11-23).
[0041]As illustrated in FIG. 3, groups of light reflective elements 132 may collectively form a series of increasing sized reflective structures, e.g., circles, to sequentially redirect light 120 along a length of elongated body 110. One of more rays of light 120 entering near a centerline C of elongated body 110 may strike a first group of reflective elements 132A nearest a respective end 112 and may be redirected toward exterior surface 116. One or more rays of light 120 slightly farther from centerline C may strike a second group of reflective elements 132B (e.g., with a larger radius), which may be positioned slightly farther into elongated body 110. The one or more rays of light 120 that strike reflective elements 132B may be redirected toward exterior surface 116. Any number of groups of reflective elements 132 (e.g., 134C, 134D, etc.) may be provided along a length of elongated body at various intervals to enable a uniform or near uniform illumination of exterior surface 116. As illustrated in FIGS. 2-3, each axially enlarging reflective array 134A, 134B may have a progressively decreasing distance from exterior surface 116 as the distance from light emitter 140A, 140B increases. Each array 134A, 134B may be any length of elongated body 110 as desired, e.g., a 50/50 split, a 30/70 split, etc. FIG. 6 shows an end view of elongated body 100 illustrating the groups of reflective elements 132A-132D of FIG. 3 from either end 112 or 114 and the light 126 that is reflected therefrom.
[0042]As illustrated in FIG. 1A, light directing element 100 may also include various types of light emitters 140 operably coupled to at least one end 112, 114 of elongated body 110 for emitting light 120 axially into elongated body 110 to strike axially enlarging reflective array(s) 134. As noted, light 120 may eventually exit through exterior surface 116 as exiting light 126. In one example, a single light emitter 140 may be operative to direct light 120 (prior to exiting light 126 exiting exterior surface 116) into first end 112 of elongated body 110, and out exterior surface 116. In another example, two light emitters 140A, 140B may be operably coupled to respective ends 112, 114 of elongated body 110 for emitting light 120 axially into elongated body 110 to strike each of the pair of axially enlarging reflective arrays 134A, 134B has one array 134A having a respective smaller end facing first end 112 of elongated body 110, and the other array 134B has a respective smaller end facing second end 114 of elongated body 110.
[0043]Light emitter(s) 140 may include any form of light emission element capable of creating the desired wavelength of light and introducing it to elongated body 110. In some examples, light 120 may enter elongated body parallel with center line C. In some examples, a beam collimator (e.g., as shown in FIG. 16) may be used in connection with light emitter(s) 140 to enable application of collimated rays of light 120. In one example, light emitter 140 may include one or more light emitting diodes (LEDs) 142. LEDs 142 may be coupled to ends 112 and/or 114 via a separate structure or fixedly coupled thereto. Alternatively, LEDs 142 can be embedded within elongated body 110, e.g., within ends 112, 114. In another example, light emitter(s) 140 may include one or more electroluminescent light emitters 144. In another example, light emitter(s) 140 may include one or more lasers 146, e.g., a gallium nitride (GaN) based laser, or a frequency doubling gallium arsenic (GaAs) laser. Light emitter(s) 140 may be part of elongated body 110, or coupled thereto using any now known or later developed coupling process, e.g., adhesive, fasteners, etc.
[0044]Light 120 and/or exiting light 126 may have any color desired. In one example, light 120 and exiting light 126 may be any color chosen for illumination and/or aesthetic purposes, e.g., white, green, orange, etc. In some examples, light emitting element 100 may also include a control system operatively coupled to light emitter(s) 140 and/or exiting light 126. The example control system may control operational features such as but not limited to: a duration of illumination, color, light intensity, and/or light irradiance of the light emitter(s) 140 and/or exiting light 126. Control system may include any now known or later developed microcontroller. Light emitting element 100 may also include at least one sensor coupled to control system to provide feedback to control system. Capacitive touch sensors, infrared (“IR”) sensors, or piezo electric sensors may be used to detect touch of the exterior surface 1116 (e.g., to change color, intensity, irradiance, etc. based on touch). Similarly, remote cameras and/or occupancy sensors may be used to determine whether exterior surface is likely to be touched (e.g., when a room is vacant there is a low probability that exterior surface will be touched).
[0045]The example sensor(s) may sense any parameter of the control environment of light emitting element 100, including but not limited to: touch of light emitting element 100, heat of a user's hand on light emitting element 100, motion of a user, motion of structure to which light emitting element 100 is coupled, temperature, light reception, and/or presence of microorganisms on exterior surface 116, etc. Sensor(s) may include any now known or later developed sensing devices for the desired parameter(s). Control system with (and without) sensor(s) may control operation to be continuous or intermittent based on external stimulus, and depending on the application. In one example, sensor(s) may detect heat/human touch, motion, or light. Sensor(s) may send the detected information to the control system, which may vary the color, intensity, or duration of disinfection of the exiting light 126.
[0046]In an example, based on a human touching a surface previously illuminated with 405 nanometer light, a sensor may detect the touch and send information to control system. The control system may then alter the light emitted from the light emitting element to disinfecting white light while in use.
[0047]In another example, where light directing element 100 comprises disinfecting properties, exiting light 126 exiting exterior surface 116 may have at least a portion thereof with a wavelength in a range of 380 to 420 nanometers (nm). This wavelength of light may inactivate, decrease, and/or kill microorganisms on surfaces. In one example, exiting light 126 may have at least a portion thereof with a wavelength of 405 nm. Exiting light 126 may solely comprise wavelengths between 380 to 420 nm, or light 120 may be converted in a number of ways, described herein, to create disinfecting light of another color such as white light. In this example, exiting light 126 exiting exterior surface 116 may have any irradiance or intensity sufficient to disinfect exterior surface 116, which may vary depending on, for example: the type of material of body 110, the level of microorganisms thereon, the extent of touching (e.g., low level bedroom door handle versus high level grocery cart handle), the type of application, etc. In one example, exiting light 126 may have an irradiance of at least 0.01-0.02 milliWatts per square centimeter (mW/cm2) across the surface area of exterior surface 116, e.g., all or at least part of exterior surface 116.
[0048]The desired exiting light 126 may be created in a number of ways. In one example, light emitter(s) 140 may emit light 120 that is the same as the desired exiting light 126 that exits exterior surface 116 of elongated body 110, e.g., light 120 may simply pass directly out exterior surface 116 as exiting light 126 after being redirected by diffuser 130. In some examples, the color of the exiting light 126 may be selected to match a color of a structure to which the device is attached. In another example, light 120 may be converted prior to exiting exterior surface 116 as exiting light 126 from one color to another color such as white light, or a disinfecting light. For example, light 120 may be converted to a white light having a portion thereof with the wavelength in the range of 380 to 420 nanometers, but also other wavelengths of light to create the white light, e.g., 450-500 nm and 550-700 nm. 450-500 nm light may be produced using one or more blue phosphors and 550-700 nm light may be produced using one or more green and/or red phosphors. In some examples, the red phosphors may be nitride phosphors. Other colors of light may also be similarly generated. In some examples, a multiple LED light emitter may be used to create various colors of light. For example, a multiple LED light emitter may comprise red, green, blue, and violet light emitters configured together for the creation of various colors of light.
[0049]In the illustrated example of FIG. 3, elongated body 110 may include a light-converting layer(s) 150 through which light 120 may travel to convert at least a portion of exiting light 126 to a wavelength(s) different from the wavelength of light 120 emitted from light emitter(s) 140. In FIG. 3, light-converting layer 150 may be embedded in elongated body 110; however, it may be located anywhere along a path of light 120 such as on ends 112, 114, or on exterior surface 116. Light-converting layer 150 may include any now known or later developed layer(s) for converting all or certain portion(s) of light 120 to different wavelengths. In some examples, light-converting layer 150 may include at least one phosphor, at least one optical brightener, and/or at least one quantum dot. Light-converting layer 150 may tune light 120 to, for example, alter a color tint of exterior surface 116 or the color tint of the material directly surrounding each of light emitter(s) 140, etc., within device 100. Light-converting layer 150 may be segmented across the layer's surface to convert light 120 to two or more different wavelengths, e.g., one segment to enable some of light 120 to pass unconverted, another segment to convert some of light 120 to another wavelength, and another segment to convert some of light 120 to yet another wavelength. In any event, exiting light 126 may be customized to provide disinfection and/or a desired color. In some examples, exiting light 126 may have a color rendering index (CRI) value of at least 70, a correlated color temperature (CCT) between approximately 2,500 K and 5,000 K and/or a proportion (e.g., between 20% and 44%) of its spectral energy measured in the 380 nm to 420 nm wavelength range.
[0050]Referring to FIGS. 7-10, a method 200 is illustrated for creating the example light directing element 100. As illustrated in FIG. 7, an extrusion system 202 may extrude a transparent, elongated body 210 having a plurality of magnetic light reflective elements 232 within transparent, elongated body 210. Transparent, elongated body 210 may include a first end 212, a second end 214, and an exterior surface 216. Elongated body 210 may be extruded using any now known or later developed extrusion system 202 capable of forming transparent, elongated body 210 with magnetic light reflective elements 232 therein. Light reflective elements 232 may be dispersed throughout elongated body 210 in any manner, e.g., random, in concentric circles, in a helix, etc. As shown in FIG. 8, one or more magnetic light reflecting element 232 may include, for example, a planar body. One or more magnetic light reflecting element 232 may include a reflective layer 234 having a reflective surface 235, and may include magnetic material (e.g., a ferromagnetic material, mica substrates coated with iron oxides (ferrite) and/or titanium dioxides, or other magnetic material) as another layer 236 or within reflective layer 234. The reflective coating may include one or more dielectric coatings to create a Bragg mirror. Other magnetic pigments that may be employed on other materials may include but are not limited to: iron oxide, and/or titanium oxide. Alternatively, the magnetic material may be a compound featuring at least one of the following elements: iron, aluminum, nickel, cobalt, samarium, dysprosium, or neodymium. One or more of the magnetic light reflecting elements 232 may be subjected to a magnetic field during manufacturing in order to temporarily or permanently magnetize them. In the simplest manifestation, the one or more of the magnetic light reflecting elements 232 may respond to the applied magnetic field, while the material of the elongated body 210 may not. Elongated body 210 may include any now known or later developed transparent material capable of extrusion, e.g., clear acrylic, diffuse polycarbonate plastic, glass, or any combination thereof.
[0051]FIG. 7 illustrates that, prior to the transparent, elongated body 210 hardening, a varying electromagnetic (EM) field may be applied along and around at least a portion of transparent, elongated body 210 to arrange a plurality of magnetic light reflective elements 232 within elongated body 210 to collectively create at least one diffuser 130 comprising at least one axially, enlarging reflective array 134 (or arrays 134A, 134B). The varying EM field may be created by an electromagnet system 260 controlled by a control system 262. Control system 262 may include any now known or later developed micro-electronic controller. Elongated body 210 may be passed through a varying EM field created by electromagnet system 260 and controlled by control system 262, which may move and/or manipulate magnetic light reflective elements 232 into groups, a helix, a cone, etc. to form diffuser 130. As the elongated body 210 is extruded into the desired cross section (or shortly thereafter) and remains formable, it may be passed through one or more variable electromagnetic fields (produced by electromagnet system 260). The fields may vary in intensity such that magnetic reflective elements 232 are moved into the desired locations. Control system 262 may also vary the rate of extrusion, temperature, and/or magnetic field strength. In some examples, applying the varying EM field may arrange magnetic light reflective elements 232 to have a progressively decreasing distance from exterior surface 216 as the array extends axially from an end 112, 114 into transparent, elongated body 210. Alternatively, as shown in FIG. 1B, the application of the varying EM field may arrange each axially enlarging reflective array 134 to include an enlarging helical arrangement of magnetic light reflective elements 132. Alternatively, as shown in FIG. 4, the application of the varying EM field may arrange each axially enlarging reflective array 134 to include groups of magnetic light reflective elements 132 collectively forming a series of increasing radius arcs. Applying the varying EM field may arrange magnetic light reflective elements 232 in groups in a series of increasing diameter circles from first end 112 towards the second end 114, or vice versa, from second end 114 towards first end 112, forming at least a portion of a cone configuration 136 (FIG. 1A). As shown in FIGS. 2 and 7, two arrays 134A, 134B may be formed with a first axially enlarging reflective array 134A facing first end 112 of the transparent, elongated body 110 for redirecting light entering first end 112; and a second axially, enlarging reflective array 134B facing second end 114 of transparent, elongated body 110 for redirecting light entering second end 114. Applying the varying EM field may arrange the magnetic light reflective elements 232 within transparent, elongated body 210 to redirect light 120 (e.g., FIG. 3) entering the elongated body toward exterior surface 116 with a substantially uniform irradiance (e.g., 0.01-0.02 mW/cm2) across at least a portion of a surface area of exterior surface 116.
[0052]FIG. 9 illustrates a method 300 for monitoring the arrangement of a plurality of magnetic light reflective elements 232 within transparent, elongated body 210 during the applying the varying EM field, e.g., using a monitoring system 264. Here, similar to FIG. 7, elongated body 210 may be passed through a magnetic field created by electromagnet system 260 and controlled by control system 262 to create a varying EM field that moves and/or manipulates magnetic light reflective elements 232 into groups and form diffuser 130. In the illustrated example of FIG. 9, control system 262 may vary the rate of extrusion, temperature, or magnetic field strength dynamically based on, for example, measurements (e.g., real-time) of the density and/or location of reflective elements 232, by monitoring system 264. Monitoring system 264 may be capable of sensing the location, either specifically or generally, of magnetic light reflective elements 232. For example, monitoring system 264 may include at least one sensing system for sensing the arrangement of magnetic light reflective elements 232 within the transparent, elongated body.
[0053]In some examples, the sensing system features a source, detector, and one or more focusing or filtering devices configured to work with radiation. The radiation may be light, ultrasound, x-rays, terahertz radiation, other known radiation, or any combination thereof. The presence and location of the magnetic light reflective elements 232 may be determined by the presence or absence of radiation in two or more measurements. For example, an optical testing method may involve shining a light into elongated body 210 perpendicular to the direction of extrusion, and monitoring the results with an image sensor. The pattern and intensity of the light hitting the sensor may vary based on how much the reflective elements redirect radiation. The sensor and/or light emitter may be rotated around elongated body 210, testing it from all angles. The light source may be, for example, a laser scanning across the diameter of the extrusions, or a collimated beam of light of the same width. Control system 262 may utilize the data collected from the image sensor to do at least one of the following: create a 3D model of the reflective array, compare the 3D model to an ideal arrangement, or compare raw data with saved data measured in the same manner from one or more ideal configurations produced previously. In another example, inductive sensing may be employed. One or more sensing coils, shielded from the field locating the reflective elements, may sense the depth of the particles within the material. Control system 262 may use the concentration of reflective elements to interpret raw data from the sensing coils into a measure of their location. Based on one or more magnetic light reflective elements 232 being out of position, control system 262 may adjust the electromagnetic field to alter the arrangement during application of the varying EM field, e.g., to apply more or less intense or differently directed electromagnetic field in a certain area of elongated body 210, or scrap/recycle a non-conforming section and apply corrections to make the next section conform. For example, control system 262 may dynamically change the electromagnets current and voltage values based on the amount and location of metal in their fields, e.g., to detect the uniformity of the distribution of the reflecting elements. Alternatively, between two or more stages of the groups of reflecting elements, arrays of smaller inductors could be located around elongated body 110 to detect the depth/concentration of the reflecting elements.
[0054]FIGS. 7 and 9 also show the transparent, elongated body 210 hardening to form