Abstract: The various embodiments of the present invention disclose an image processing method and system for capturing a refocusable image set. The method comprises of segmenting a field of view into a plurality of grids, determining a sharpness level associated with each of the plurality of grids, identifying one or more regions based on the determined sharpness level of each of the plurality of grids, each region comprising one or more of the plurality of grids and capturing an image associated with each of the identified one or more regions to form the refocusable image set. The method further comprises of detecting a refocusing action on an object, in the field of view, having an associated illumination level and varying the associated illumination level of the object based on the detection.

Abstract: A five-piece optical lens for capturing image and a five-piece optical module for capturing image, along the optical axis in order from an object side to an image side, include a first lens which can have positive refractive power, and has an object-side surface which can be convex; a second lens with refractive power; a third lens with refractive power; a fourth lens with refractive power; and a fifth lens which can have negative refractive power, wherein an image-side surface thereof can be concave, and at least one surface of the fifth lens has an inflection point; both surfaces of each of the five lenses are aspheric. The optical lens can increase aperture value and improve the imaging quality for use in compact cameras.

Abstract: A lens system according to the present disclosure includes a plurality of lens groups, each having at least one lens element, the lens system including, in order from an object side to an image side, a first lens group that is fixed with respect to an image plane in focusing from an infinity in-focus condition to a close-object in-focus condition; an aperture diaphragm; a second lens group that moves in a direction of an optical axis in the focusing; a third lens group that is fixed with respect to the image plane in the focusing; a fourth lens group that moves in the direction of the optical axis in the focusing; and a lens group closest to the image side, wherein the following conditions (1) and (2) are satisfied: 2.5<|f2/f4|<6.5 ??(1) 0.5<|f/f4|<1.5 ??(2) where f2 is a focal length of the second lens group, f4 is a focal length of the fourth lens group, and f is a focal length of the entire optical system in an infinity in-focus condition.

Abstract: This invention provides an optical lens, which comprises, in order from an object side to an image-forming side, a first lens group having positive refractive power and a second lens group having negative refractive power. The first lens group includes: in order from the object side to the image-forming side, a first lens having refractive power and a second lens having refractive power. The second lens group includes: in order from the object side to the image-forming side, a third lens having refractive power and a fourth lens having refractive power, wherein the fourth lens has a concave surface toward the object side.

Abstract: A five-piece optical lens for capturing image and a five-piece optical module for capturing image, along the optical axis in order from an object side to an image side, including a first lens with positive refractive power having an object-side surface which can be convex; a second lens with refractive power; a third lens with refractive power; a fourth lens with refractive power; and a fifth lens which can have negative refractive power, wherein an image-side surface thereof can be concave, and at least one surface of the fifth lens has an inflection point; both surfaces of each of the five lenses are aspheric. The optical lens can increase aperture value and improve the imaging quality for use in compact cameras.

Abstract: The present invention discloses a camera lens including, lined up in turn from the object side: a stop, a first lens with positive refractive power, a second lens with negative refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, a fifth lens with negative refractive power. The camera lens satisfies the following conditions: 0.70?f1/f?0.78, ?1.90?f2/f??1.30, ?400.00?f3/f??65.00, ?1.20?(R1+R2)/(R1?R2)??1.00, 1.20?(R7+R8)/(R7?R8)?1.90, 0.08?d6/f?0.13.

Abstract: A camera lens system is disclosed. The camera lens system includes a first lens group having a first lens which has a positive refractive power; a second lens group having a second lens which has a negative refractive power and a third lens which has a negative refractive power; a third lens group having a fourth lens which has a concave image side surface and a positive refractive power; a fourth lens group including a fifth lens which has a convex image side surface and a positive refractive power; a fifth lens group having a sixth lens which has a concave image side surface and a negative refractive power. An image side surface of the second lens is connected to an object side surface of the third lens.

Abstract: A camera lens system is disclosed. The camera lens system includes five lens groups lined up from the object side. The lens groups includes a first lens group having a first lens having a positive refractive power; a second lens group having a second lens having a negative refractive power; a third lens group having a third lens having a positive refractive power and the a fourth lens having a negative refractive power; a fourth lens group having a fifth lens having a convex image side surface and a positive refractive power; a fifth lens group having a sixth lens having a concave image side surface and a negative refractive power. An image side surface of the third lens is connected to the an object side surface of the fourth lens.

Abstract: A compact low-cost imaging lens which provides brightness with an F-value of 2.5 or less and a wide field of view and corrects aberrations properly, meeting the demand for low-profileness. The imaging lens elements are arranged in the following order from an object side to an image side: a first lens with positive refractive power having a convex surface on the object side; a second lens with negative refractive power; a third lens with positive or negative refractive power having at least one aspheric surface; a fourth lens with positive refractive power; a fifth lens as a meniscus double-sided aspheric lens having a concave surface near an optical axis on the image side; and a sixth lens as a meniscus lens having a concave surface near the optical axis on the object side. The both surfaces of the fifth lens have pole-change points off the optical axis.

Abstract: A compact low-cost imaging lens which provides brightness with an F-value of 2.5 or less and a wide field of view and corrects aberrations properly, meeting the demand for low-profileness. The imaging lens elements are arranged in the following order from an object side to an image side: a first lens with positive refractive power having a convex surface on the object side; a second lens with negative refractive power; a third lens with positive or negative refractive power having at least one aspheric surface; a fourth lens with positive refractive power; a fifth lens as a meniscus double-sided aspheric lens having a concave surface near an optical axis on the image side; and a sixth lens as a meniscus lens having a concave surface near the optical axis on the object side. The both surfaces of the fifth lens have pole-change points off the optical axis.

Abstract: Provided is a projection lens including: a first lens, a reflective optical device, a second lens and a third lens from an image side of the projection lens to an object side of the projection lens in turn. The first lens is of a negative focal power, an image side of the first lens is concave; the reflective optical device enables light to be bended; the second lens is of a positive focal power, an object side of the second lens is convex; the third lens is of a positive focal power, an object side of the third lens is convex. A diaphragm is arranged between first lens and second lens, the projection lens meets: 0.4<ImgH/D<0.7, wherein ImgH equals to a half-length of an object diagonal, D represents a vertical height from the image side of the first lens to a center axis perpendicular to an object.

Abstract: An optical system, which may include a fish-eye lens including a whole view angle larger than 180 degrees, includes in order from an object-side to an imaging-side, a first lens group including a negative focal distance, an aperture, and a second lens group including a positive focal distance. An infrared cutting coat is coated on a lens surface that includes curvature of a lens among lenses included in the second lens group.

Abstract: A zoom lens includes in order from an object side: a first lens unit having a negative refractive power, and a second lens unit having a positive refractive power, wherein the first and second lens units move along respective loci different from each other during zooming; the first lens unit has two negative lenses arranged continuously from the object side; and a focal length of the first lens unit, a focal length of the second lens unit, a focal length of the zoom lens at a wide angle end, a focal length of a negative lens G11 arranged on most object side in the negative lenses contained in the first lens unit, and a focal length of a negative lens arranged on second most object side in the negative lenses contained in the first lens unit.

Abstract: A reflector for helio-thermal systems may include a metallic carrier plate and a reflective coating that is applied to the carrier plate and is constructed from at least one metallic reflective layer and at least one protective layer applied to the reflective layer. Such reflectors have high reflective capabilities, are robust in relation to mechanical stress, and can be manufactured cost effectively. Such reflectors are also lightweight and dimensionally stable due to the fact that the carrier plate may be formed from a sandwich plate having at least one nonmetallic intermediate layer disposed between an upper and lower metallic cover plate. The upper cover plate may have a smoothed surface to which the reflective layer can be applied. The smoothed surface prior to the reflective layer being applied may have an arithmetic mean surface parameter Ra of less than 0.03 ?m. Methods for manufacturing such reflectors are also disclosed.

Abstract: A compact microscope including an enclosure, a support element, a primary optical support element located within the enclosure and supported by the support element, at least one vibration isolating mount between the support element and the primary optical support element, an illumination section, an objective lens system, a sample stage mounted on the primary optical support element, an illumination optical system to direct an illumination light beam from the illumination section to the sample stage, and a return optical system to receive returned light from sample stage and transmit returned light to a detection apparatus, wherein the illumination optical system and return optical system are mounted on the primary optical support element.

Abstract: A tomography accessory device for supporting a sample relative to the imaging assembly of a microscope has an electric positioning motor supported on the existing sample supporting stage of the microscope. An output shaft of the positioning motor is supported for rotation about an output axis parallel to a plane of the stage and a controller acts to control the motor so as to rotate the output shaft between a plurality of different angular positions about the output axis. An adjustable assembly supports a sample holder relative to the outer shaft such that i) the sample holder is translatable relative to the output shaft along at least one translation axis oriented generally perpendicularly to the output axis, and ii) the sample holder is pivotable relative to the output shaft about at least two pivot axes which are transverse to one another and which are generally perpendicular to the output axis.

Abstract: The present invention relates to a microscope (30) comprising an objective (1) and an illumination unit (31) for selectable generation of an orthoscopic beam path (14) proceeding through the objective (1) for pointlike scanning illumination, and of a conoscopic beam path (13) proceeding through the objective (1) for evanescent illumination of an object, the illumination unit comprising: a light source (10) for generating illuminating rays along an illuminating beam path (32); a displacement unit (7) for deflecting the illuminating beam path (32); a scanning eyepiece (8), placed after the displacement unit (7), for focusing the illuminating rays into an image plane (11) of the scanning eyepiece (8); and a mirror surface (6) arranged in the image plane (11) of the scanning eyepiece (8), having a transparent region (27) for generating the orthoscopic beam path (14) and having an at least partly reflective region (28) facing toward the scanning eyepiece (8) for generating the conoscopic beam path (13) from the il

Abstract: An apparatus for viewing a biological sample that functions as both a microscope and an interferometer. A short-coherence light source directs light onto the sample. A Fourier transform lens and a pixel-array detector are positioned to collect light scattered by the sample. An optic fiber assembly conveys a reference beam from the short-coherence light source. The detector collects the reference beam and the signal beam and uses coherence gating to acquire interferometric image data. In some embodiments the axis of the incident light striking the sample and the axis of collected scattered signal light form an angle of less than 180 degrees and advantageously an angle between 120 and 150 degrees. A method of converting a microscope into an interferometer is also disclosed.

Abstract: Aberration-corrected incoherent imaging methods and systems that can acquire a sequence of coherent images and an incoherent image of a specimen, implement an embedded pupil function recovery process in junction with Fourier ptychographic technique to construct an improved resolution image and pupil function of the imaging system using the sequence of coherent images, determine an optical transfer function based on the estimated pupil function, and remove the aberration from the incoherent image using a deconvolution process to generate an aberration-corrected incoherent image.

Abstract: An illumination system for illuminating a region within a field of view of an imaging device with a spot from a laser.

Abstract: A total internal reflection light illumination apparatus includes a light source providing illumination light L1, a spatial light modulator inputting the illumination light L1 and converging and outputting the illumination light L1 by presenting a lens pattern, an objective lens illuminating an object substrate with illumination light L2 converged and output by the spatial light modulator, and a calculation unit providing, to the spatial light modulator, the lens pattern corresponding to at least one of a desired polarization state, desired penetration length, desired shape, and desired light intensity of the evanescent light L3. The lens pattern converges the illumination light L2 on a pupil plane of the objective lens.

Abstract: A microscope system is made available, said microscope system including: a microscope with an observer beam path with at least one camera for obtaining at least one electronic image of an observation object with a deep channel with a base, a motor-driven mount and/or a motor-driven stand, on which the microscope is mounted, a detection unit for detecting the focal depth set at the microscope, an image processing unit connected to the detection unit for the receiving focal depth and connected to the at least one camera for receiving the at least one electronic image, which image processing unit establishes the image portion in the at least one electronic image constituting the base of the deep channel in the electronic image, and a control unit connected to the image processing unit for receiving the established alignment for outputting control signals.

Abstract: An image pickup apparatus includes an image pickup element and an optical system. The image pickup element includes a plurality of pixels, and the plurality of pixels is arranged in rows two-dimensionally. The optical system includes in order from an object side, a first lens unit which includes a plurality of lenses, a stop, and a second lens unit which includes a plurality of lenses. The first lens unit includes a first object-side lens which is disposed nearest to an object, and the second lens unit includes a second image-side lens which is disposed nearest to an image. The following conditional expressions (1), (2), (3), (4), and (5) are satisfied: 3250<2Y/p??(1), ?1.0<???(2), CRAobj<10 deg??(3), 2.0<LL/?(Y×Yobj)<15.0??(4), and 0.5<LTL/Doi<0.95??(5).

Abstract: This invention teaches a binocular telescope wherein wedge prisms are positioned in the optical path of each telescope to control the amount of perceived parallax. The invention has several advantages including better depth perception, increased field of view, and the possibility to view close objects.

Abstract: A target adjustment apparatus may be provided. The target adjustment apparatus may include an optical targeting device having a first zero. The target adjustment apparatus may further include an optical adjustment lens removably disposed in a line of sight between a target and the optical targeting device. The optical adjustment lens may shift a target image before it reaches the optical targeting device, creating a second zero.

Abstract: An image pickup unit includes an objective lens unit, cover glass fixed on a light receiving surface of an image pickup device, a circular optical member stuck to a front end face of the cover glass and having a diameter smaller than a diagonal line length of the cover glass, a holding frame having a circular fitting hole in which the optical member is fit from a rear, a first light blocking member disposed in a front of the optical member, and a second light blocking member disposed between a rear end face of the optical member and a front end face of the cover glass.

Abstract: An operation mechanism for an insertion device includes a moving section, an operation section configured to operate the moving section, a frame body fixed in the operation section, a long member movable along the frame body according to the operation of the operation section, a first tabular member provided between the frame body and the long member in the operation section, and a plurality of first projecting sections projecting from the first tabular member to the frame body side and disposed in a plurality of holes of the frame body.

Abstract: Disclosed is a manufacturing method for a wavelength conversion device, comprising: preparing a plurality of wavelength conversion modules, each wavelength conversion module comprising a ceramic substrate, a reflecting layer and a fluorescent powder layer, said layers being stacked sequentially and formed into one piece; installing and fixing the plurality of wavelength conversion modules on one surface of a base substrate. By arranging different fluorescent powders respectively on the different wavelength conversion modules, a plurality of wavelength conversion modules can be produced separately at the same time, thereby significantly shortening the production cycle. Each such module is produced independently and is thus not subject to the restrictions of the characteristics of other fluorescent powders. This is beneficial for the optimization of the various processes, and a wavelength conversion device having optimal performance is thereby obtained.

Abstract: Provided herein are a reflective lens capable of changing a focal length and an optical system using the same. An active reflective lens according to an embodiment includes: a lens unit including material that is deformable in response to an electric signal; a support unit configured to support the lens unit; a base unit formed below the support unit; a first electrode formed on the lens unit; and a second electrode formed on the base unit. The distance between the first electrode and the second electrode is determined depending on a shape of an upper surface of the base unit, and the distance between the first electrode and the second electrode varies depending on regions of the lens unit.

Abstract: In described examples, a DMD includes an array of micromirror pixels. Each pixel includes a right electrode on a first side of the pixel, a left electrode on a second side of the pixel adjacent the first side, and a cantilevered beam supporting a mirror. The cantilever beam tilts on two axes of translation: pitch and roll. The mirror has: a first landed position (on a first and second spring tip) over the right electrode; and a second landed position (on the first and a third spring tip) over the left electrode, such that the first landed position and the second landed positions are 90° apart. In transitioning from the first landed position to the second landed position, the mirror maintains contact with the first spring tip while rolling from the second spring tip to the third spring tip.

Abstract: A spatial light modulator comprises, a first light modulation element having a substrate, a reflecting mirror, a movable portion displaced relative to the substrate while supporting the reflecting mirror, and a top electrode adsorbing the movable portion by electrostatic force between the movable portion and the top electrode in a position farther away from the substrate than the movable portion, a second light modulation element placed adjacent to the first light modulation element in the substrate, having a reflecting mirror, a movable portion displaced relative to the substrate while supporting the reflecting mirror, and a top electrode adsorbing the movable portion by electrostatic force between the movable portion and the top electrode in a position farther away from the substrate than the movable portion, and electrode supporting portions commonly supporting the top electrodes of the first light modulation element and the second light modulation element relative to the substrate.

Abstract: Disclosed examples include ultrasonic cleaning systems, driver integrated circuits and methods for cleaning a lens, in which an oscillating drive signal is provided to an ultrasonic transducer and the driver controls the frequency of the drive signal according to a current sense signal representing a drive current flowing in the transducer. The driver sweeps the drive signal frequency and compares the sensed current values with predetermined profiles corresponding to a clean lens and a lens with one or more known contaminants, and generates the drive signal at one or more frequencies corresponding to peaks or valleys of the sensed current values or predetermined frequencies to promote cleaning of the lens.

Abstract: A seamless lens cover, and methods of forming such a seamless lens cover. The cap structure that covers a camera of a rotating panoramic camera system includes a seamless lens cover through which images are obtained by the camera. The cap structure may be injection molded at an initial lens cover thickness, and then a portion of the as molded initial lens cover thickness may be removed (e.g., by machining away) to achieve the final desired thickness. By such a method, the lens cover may be injection molded at thicknesses suitable for injection molding (e.g., about 0.06 to about 0.1 inch), after which most of the thickness may be machined away, to provide a seamless lens cover having a thickness of less than about 0.015 inch, exhibiting at least 60% transmittance to the thermal spectrum, no lensing characteristics, and no curvature effect.

Abstract: An optical system driving device includes a movable body that is movable in at least three degrees of freedom, and a light transmissive unit integrally mounted to the movable body. The optical system driving device also includes a driving unit that moves the movable body in at least three degrees of freedom, and a detection unit that detects a position of the movable body in each of at least three degrees of freedom. The detection unit includes a light-emitting unit that emits light toward the light transmissive unit, and an optical detector that receives light emitted from the light-emitting unit and passing through the light transmissive unit and outputs a light-receiving signal based on the received light. The detection unit also detects a position of the movable body in each of at least three degrees of freedom based on the light-receiving signal from the optical detector.

Abstract: A glazing for information display includes an assembly of two transparent inorganic or plastic sheets, connected together by a thermoplastic or adhesive interlayer or by multilayer sheets incorporating the interlayer, wherein a luminophore material is incorporated to enable the display. One of the luminophores includes a benzene ring substituted at least by: a first ester —COOR group, wherein R is a linear or branched carbon-based group including a main carbon-based chain of at least six consecutive carbon atoms, the R group including, if the chain is linear, more than 10 carbon atoms and, if the chain is branched, at least 7 carbon atoms, optionally a second —COOR? group, wherein R? is another hydrocarbon-based group or hydrogen, the second group optionally being in para position on the benzene ring with respect to the first ester group, two hydroxyl —OH groups that are optionally in para position on the benzene ring.

Abstract: A head-up display device that is to be equipped to a moving body and displays an image projected on a projection surface of the moving body to be visually recognized as a virtual image from an inside of the moving body includes a light source, an image displaying panel and a common mirror. The image displaying panel luminously displays an image using a light of the light source passing through a first optical path and projecting the image on the projection surface via a second optical path. The common mirror reflects and leads the light of the light source toward the image displaying panel in the first optical path, and a light of the image toward the projection surface in the second optical path.

Abstract: An image display apparatus includes a light source device including a light source unit; a scanning optical system including an image forming unit on which an intermediate image is formed by light from the light source unit; and a virtual image optical system configured to guide light of the intermediate image by using a reflecting mirror and a curved transmissive reflection member. The scanning optical system includes an optical scanning unit configured to scan the light from the light source unit in a main scanning direction and a sub-scanning direction of the image forming unit. The image forming unit is a transmissive member curved with a convex surface toward the reflecting mirror.

Abstract: An assembly comprises a vehicle windscreen, and a stack of first and second films at least partially coating a face of the windscreen, the first film being arranged between the windscreen and the second film, wherein: the second film is a screen suitable for displaying an image projected on the face thereof opposite the windscreen; and the first film is a reflector suitable for reflecting light transmitted by the second film towards the windscreen.

Abstract: A system and method are disclosed for displaying virtual content. When a user is settled in a given geographic area, a full version of the content may be displayed at user-defined or processor-defined location. When the user is moving, for example leaving the geographic area, a mobile version of the content may be displayed at a body-locked position peripheral to the user's view.

Abstract: Disclosed is an improved diffraction structure for 3D display systems. The improved diffraction structure includes an intermediate layer that resides between a waveguide substrate and a top grating surface. The top grating surface comprises a first material that corresponds to a first refractive index value, the underlayer comprises a second material that corresponds to a second refractive index value, and the substrate comprises a third material that corresponds to a third refractive index value.

Abstract: A spectacle lens for a display device can be fitted on the head of a user and generate an image. A spectacle lens body includes a front side and/or the rear side that are curved, and at least a first and a second partial body, the mutually facing boundary surfaces of which are in direct contact, and as seen in top view onto the spectacle lens, a coupling-in section in an edge area of the spectacle lens and a coupling-out section in a central area of the spectacle lens. The spectacle lens can guide light bundles of pixels of the generated image to the coupling-out section and couple them out of the spectacle lens via the coupling-out section. A flat first reflecting surface and a flat second reflecting surface spaced apart from the first reflecting surface are provided in the spectacle lens body.

Abstract: An optical assembly including first (340) and second (312) polarizers and a liquid crystal module (314) disposed therebetween, with the first and second polarizers making an oblique angle of at least 5 degrees therebetween is disclosed. Optical devices like head mounted displays (300) including the optical assembly are also disclosed.

Abstract: A head up display (HUD) may include: a control unit configured to determine contents to be projected on the visible area of a driver and the projection position of the contents; a picture generation unit (PGU) configured to output a picture according to control of the control unit; and an optical system configured to change an optical path of the picture outputted from the PGU so as to project the picture on the visible area of the driver. The optical system may divide the output picture into two or more pictures having different projection distances, and project the pictures.

Abstract: A head up display (HUD) for a vehicle may include: an aspheric mirror configured to reflect an HUD picture to a windshield; a picture generation unit (PGU) configured to directly project the HUD picture on the aspheric mirror; and a control unit configured to calculate a display level of the HUD picture to be displayed on the windshield, based on eye level information of a driver, and control the PGU to output the HUD picture at a position and area corresponding to the calculated display level.

Abstract: An apparatus, system and method for microscopy. The apparatus, system and method includes a stage configured to receive an item; a tunable acoustic gradient index of refraction (TAG) lens having a first aspect positioned to image the received item, wherein the first aspect of the TAG lens is configured to have an optical power profile in accordance with an operational frequency of the TAG lens; one or more lenses configured to magnify an image of the received item at a viewing point; and at least one pulsed light source configured to illuminate the received item and to pulse at one or more points within the optical power profile of the TAG lens.

Abstract: A field mapping optical system and method for converting a light beam having a known spatially coherent first optical field to a second optical field with a required intensity distribution and flat wavefront at a desired distance from the system, by creating an intermediate optical field, between the first and second optical fields, the intermediate optical field being derived from the inverse Fourier transform of the second optical field. The optical system provides a compact and simplified field mapper.

Abstract: There are disclosed a liquid crystal panel and method for the manufacture thereof, and a 3D display apparatus, for enabling left-eye and right-eye images to be separated directly by means of a liquid crystal cell and the manufacturing process of a naked-eye 3D mode liquid crystal cell to be simplified. The liquid crystal panel comprises an upper substrate, a lower substrate and a liquid crystal cell formed of liquid crystal molecules located between the upper and lower substrates. The liquid crystal cell comprises a display layer and a grating layer, the grating layer being arranged in proximity to the upper substrate, the grating layer comprising a light shielding region and a light transmitting region, the light shielding region comprising light shielding liquid crystal molecules, the light transmitting region comprising light transmitting liquid crystal molecules, the light shielding region and the light transmitting region being arranged alternately.

Abstract: The present invention provides a functional material, its preparation method, a three-dimensional display raster and a display device, which belongs to the display technical field and can solve the pollution problem in current three-dimensional display devices.

Abstract: Systems and methods herein are directed to a dual-sided Pepper's Ghost Illusion is shown and described. In particular, various embodiments are described that allow using multiple image sources (e.g., projected bounces and/or panel displays) so the holographic image can be seen from both sides of the holographic system. In one embodiment, a specifically designed “Z frame” may be used to minimize the visible components in such a dual-sided system (e.g., particularly for smaller displays).

Abstract: Systems and methods herein are directed to foil tensioning systems for Pepper's Ghost Illusion. In one embodiment, a roller-based foil tensioning system provides for a holographic foil to be secured to a roller system on two or four sides, rolled outwards, and are then bolted in place, tightening the holographic screen material. In another embodiment, a frame-based foil tensioning system provides for the foil to be secured to a frame system on two or four sides, stretched outwards by expansion of the frame's size (e.g., by a screw jack system), and then bolted in place (while tightened). Illustratively, the foil can be secured to a tensioning system (e.g., the roller system, the expanding frame, or any frame that can be pulled apart) in a variety of manners (e.g., locking strips or snaps and a groove, loops and a rod, two rods with a foil loop, etc.).