Abstract: Provided is a polymer dispersed liquid crystal display device including: a pair of substrates including an electrode on at least one substrate; and a composite layer disposed between the pair of substrates. The composite layer includes a liquid crystal component and a polymer network constituted by a cured product of a photopolymerizable liquid crystal compound, and is in a transparent state when no voltage is applied and in a scattering state when a voltage is applied, and the polymer network has a helical structure with a number of turns of from one to less than eight in the composite layer.

Abstract: The present disclosure provides a display device, including: a light emitting device and a light adjusting layer, the light adjusting layer being on a light emitting side of the light emitting device, and the light emitting device being configured to generate and emit light having a wavelength in a wavelength range of visible light, wherein the light adjusting layer is configured to block light having a wavelength in a partial wavelength range of blue light from passing through when subjected to an external stimulus and allow the light having the wavelength in the partial wavelength range of blue light to pass through when the external stimulus is removed, and the light adjusting layer includes a responsive photonic crystal.

Abstract: Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may use transmissions causing power density exposure (PDE) to nearby users. To reduce the PDE of an antenna module (e.g., below a maximum PDE threshold), the UE may implement a shielding strip around the antenna module. For example, the antenna module may include a substrate having a first surface and a set of antenna elements on the first surface. The shielding strip may enclose the set of antenna elements of the antenna module and extend away from the first surface above the antenna elements. The shielding strip may reduce PDE outside a field of view of the antenna module. Additionally, in some cases, the placement of the antenna module in the UE and the materials used for constructing the UE may further reduce PDE.

Abstract: According to an aspect, a liquid crystal display device includes: a first substrate provided with a first electrode portion that includes a plurality of strip electrodes arranged in a first direction and that is configured to generate a transverse electric field in the first direction; a liquid crystal layer in which liquid crystal molecules are oriented in the first direction when the transverse electric field is not generated; a second substrate facing the first substrate across the liquid crystal layer; and an electrode provided at the second substrate.

Abstract: There is provided a liquid crystal display device capable of preventing a decrease in voltage holding ratio (VHR) of a liquid crystal layer and an increase in ion density (ID) and resolving the problem of display defects such as white spots, alignment unevenness, image sticking, and the like. The liquid crystal display device prevents a decrease in voltage holding ratio (VHR) of a liquid crystal layer and an increase in ion density (ID) and suppresses the occurrence of display defects such as image sticking, and the like. The liquid crystal display device is useful for an IPS-mode or FES-mode liquid crystal display device for active matrix driving. The application of the device can include liquid crystal TVs, monitors, cellular phones, smart phones, and the like.

Abstract: A ferroelectric liquid crystal composition having a chiral smectic C-phase is disposed as a liquid crystal composition layer between a first substrate and a second substrate arranged between two polarizing plates of which the planes of polarization are orthogonal to each other. The substrates are provided with vertically oriented films, respectively, and at least one of them is provided with orientation treatment that can form a pretilt angle in a certain direction. The C-director of the liquid crystal molecule is oriented in the certain direction at a portion being in contact with the substrate provided with the orientation treatment and is twisted by at least 180° between the first substrate and the second substrate. At least one of the substrates is provided with a pair of electrode structures generating electric fields approximately parallel to each other.

Abstract: A liquid crystal display device which can exhibit a blue phase stably is manufactured. A first substrate and a second substrate are attached by a sealant interposing a liquid crystal layer comprising a liquid crystal composition therebetween, an alignment state of the liquid crystal layer is set to be an isotropic phase by heat treatment, the liquid crystal layer is irradiated with light so as to perform polymer stabilization treatment on the liquid crystal layer, and an alignment state of the liquid crystal layer is changed from an isotropic phase to a blue phase in the light irradiation. Thus, a liquid crystal display device which suppresses a defect which shows an alignment state other than a blue phase (an alignment defect) is manufactured.

Abstract: The present invention relates to modulation elements for electromagnetic radiation and to modulation devices and systems comprising these devices, such as e.g. television screens and computer monitors, as well as to micrometer wave components. The modulation elements according to the invention comprise a mesogenic modulation medium with a dielectric anisotropy, which shows two or more distinct transitions upon application of an electric field. The mesogenic modulation media used in the modulation elements for electromagnetic radiation are also a subject of the present invention.

Abstract: A display panel comprises a first and a second substrates and a BP liquid crystal layer. A first electrode is provided on the first substrate, a second electrode is provided on the second substrate, and reflection portions each having a first and a second reflection surfaces are provided between the first and second substrates. When light is transmitted to the panel, the light is reflected on the first reflection surface of the reflection portion and the light after the first reflection is transmitted to an adjacent reflection portion through the liquid crystal layer and is reflected on the second reflection surface of the adjacent reflection portion. When different voltages are applied, the liquid crystal layer will shift the phase position of the light passing therethrough, while when there is no voltage, the liquid crystal layer will not shift the phase position of the light passing therethrough.

Abstract: A liquid crystal display device includes a first substrate, a second substrate, a liquid crystal layer disposed between the first substrate and the second substrate, and an electrode group provided on at least one of the first substrate and the second substrate, and that applies an electric field to the liquid crystal layer, wherein the liquid crystal layer contains at least one liquid crystalline compound, and at least one chiral dopant, wherein one of the liquid crystalline compounds contained in the liquid crystal layer develops a blue phase liquid crystal, and wherein the liquid crystal layer has a storage elastic modulus G? of 4,000 Pa or more at 25° C. and 1 Hz frequency.

Abstract: Thermochromic liquid crystal filters are fabricated by providing two polarizers oriented at offset polarity with respect to each other; providing alignment structures adjacent the inner surfaces of the polarizers; placing a plurality of spacers between the polarizers; and filling a space created by the spacers with a thermotropic liquid crystal that acts as a depolarizer in a nematic state. The filter acts as a wave block when the liquid crystal is in an isotropic state. Alternatively, the filters can be created by encapsulating a thermochromic liquid crystal with a polymer material to form a flexible film and orienting the thermochromic liquid crystal in the polymer material to create a structure that functions as a thermochromic optical filter. Such filters can control the flow of light and radiant heat through selective reflection, transmission, absorption, and/or re-emission. The filters have particular application in passive or active light-regulating and temperature-regulating films and materials.

Abstract: The liquid crystal display device may include a first electrode; a second electrode facing the first electrode and forming a vertical electrical field together with the first electrode; a blue phase liquid crystal layer provided between the first electrode and the second electrode; and a first prism sheet provided to face the second electrode with the first electrode between the second electrode and the first prism sheet. The first prism sheet changes a path of incident light so that the incident light from the outside obliquely enters the blue phase liquid crystal layer with respect to the vertical electrical field.

Abstract: A liquid crystal material in which liquid crystal molecules have uniform alignment state is provided. A liquid crystal layer containing a liquid crystal material is included between a TFT array substrate and an opposed substrate. The liquid crystal material has a phase system continuously showing an isotropic phase, a nematic phase, and a smectic ‘A’ phase in this order as temperature changes from higher state to lower state and shows electroclinic effect in the smectic ‘A’ phase. As the liquid crystal material is heated (temperature is increased), the nematic phase is shown after the smectic ‘A’ phase without other phase in between, and the isotropic phase is shown after the nematic phase without other phase in between. Since the alignment state of the liquid crystal molecules becomes uniform, the transmittance is precisely controlled.

Abstract: The invention relates to a user interaction device (200, 300) comprising an optical module (210, 310) having a layer (5) of a substance being electrically switchable between a first visual state and a second visual state, and an electrical switch (6a, 6b) for electrically switching the substance between the first and second visual states, a detector (6a, 11b) for detecting the presence of a physical object, and a control unit (290, 390) for controlling the electrical switch in response to the detection of presence of the physical object.

Abstract: A switchable autostereoscopic display device comprises a display panel (60) and an imaging arrangement (620 for directing the output from different pixels to different spatial positions to enable a stereoscopic image to be viewed. The imaging arrangement comprises a blue phase LC material. A controller switches the blue phase material to an isotropic state for the 2D mode and to a birefringent state for the 3D mode. This arrangement enables a switchable lens arrangement to be formed without alignment layers. This can give a high angle performance thin switchable arrangement.

Abstract: A liquid crystal display device includes: first and second substrates between which a liquid crystal forming material is sandwiched and which are disposed to be opposite to each other; a pair of electrodes including one and the other electrodes; a control means for controlling a voltage applied between the electrodes; and a temperature detector. The control means applies a voltage, by which a change of light transmittance occurs based on an induction and disappearance phenomenon of a nematic phase in the liquid crystal forming material, between the electrodes when a temperature of the liquid crystal forming material is in an isotropic phase temperature range, and the control means applies a voltage, by which a change of light transmittance occurs based on a change of orientation of directors of the liquid crystal forming material, between the electrodes when the temperature of the liquid crystal forming material is in a nematic phase temperature range.

Abstract: A polymer-dispersed liquid crystal system has a continuous polymer structure having defined therein a plurality of discrete bodies of liquid crystal material. The bodies of liquid crystal material exhibit a polydomain operating state in which the liquid crystal material within each body is arranged in multiple domains, each domain being defined by a quantity of liquid crystal material whose molecules have a substantially common identifiable alignment in at least one axis, wherein the resolved alignments of neighboring domains diverge substantially from one another and are stable over time.

Abstract: A liquid crystal display includes a display section performing display using a liquid crystal, a substrate disposed to face a bottom surface of the display section and having a circuit for driving the liquid crystal mounted thereon, and a heat diffusing section disposed in contact with the bottom surface of the display section and a top surface of the substrate and having thermal conductivity higher than the thermal conductivity of air.

Abstract: Provided is an electro-optical device which allows high-speed response and has high luminance and contrast.

Abstract: A photodisplay device in which an optically addressed image can be viewed indefinitely, erased and readdressed with a new image is disclosed. Optically responsive reversible photochiral materials are incorporated into a bistable cholesteric liquid crystal in an electrooptic display cell. A high resolution image exposed on the cell is fixed by a low voltage pulse to unpatterned electrodes and can be, at a later time, erased with a high voltage pulse.

Abstract: A bistable electro-optic display is updated by writing an image on the display using a first drive scheme capable of driving pixels to multiple gray levels, and thereafter varied using a second drive scheme using only two gray levels, at least one of which is not an extreme optical state of the pixel.

Abstract: A liquid crystal display includes a pair of substrates and a liquid crystal layer interposed between the substrates and has a reflective area and a transmissive area. At least one of the substrates is provided with a retardation film whose phase difference differs between the reflective area and the transmissive area. Alternatively, at least one of the substrates is provided with a retardation film whose slow axis differs between the reflective area and the transmissive area.

Abstract: The present invention discloses a multilayer dielectric optical structure wherein one of the optical materials in the multilayer structure shows an optically isotropic state above and a birefringent state below a characteristic temperature Tc near the room temperature. The optical structure reflects a predetermined wavelength range of electromagnetic radiation above the Tc but allow the same to transmit through below the Tc. The predetermined wavelength can be the near infrared radiation from 700 nm to 2500 nm, and the optical structure rejects solar heat in warm summer days but admits the same to interior on a colder winter day.

Abstract: A liquid crystal display device is provided with an electrode structure for effective utilization of optically isotropic liquid crystals. Such a liquid crystal display device comprises a first substrate; a second substrate; polarizing plates provided on the first substrate and the second substrate, respectively; a liquid crystal layer disposed between the first substrate and the second substrate; and pixel electrodes and common electrodes provided on the first substrate, wherein the liquid crystal layer has such a property that optical anisotropy is induced therein by a change of an optically isotropic state caused by a voltage; wherein ones of the pixel electrodes and the common electrodes are formed in an inter-digital form, while the other ones are formed in a flat plate, and wherein an electric field is applied to the liquid crystal layer by a potential difference between the pixel electrodes and the common electrodes.

Abstract: A plurality of display elements each includes two signal lines: S1 and S2. An electrode 4, which is one of the electrodes constituting an element capacitor Cp, is connected to the signal line S1 via a switching element TFT1, while the other electrode 5 is connected to the signal line S2 via a switching element S2. The gate electrodes of the switching elements TFT1 and TFT2 are connected to a single common scanning line G. With this structure the drive voltage applied to the element capacitor can be increased even when a TFT has a limited withstand pressure.

Abstract: Disclosed herein is a liquid crystal device which includes first and second substrates which face each other and a liquid crystal layer interposed between the first substrate and the second substrate, and transitions an alignment state of liquid crystal molecules of the liquid crystal layer from a spray alignment to a bend alignment to perform display or optical modulation, the liquid crystal device including: a protrusion which is provided on at least one of the first substrate and the second substrate at the side of the liquid crystal layer and has a concave portion; and an alignment film which is provided on the surfaces of the first substrate and the second substrate at the side of the liquid crystal layer so as to cover the surface of the protrusion including the concave portion.

Abstract: The invention relates to an electro-optic light control element, electro-optic displays containing said elements and display systems such as TV screens and computer monitors. The inventive light control elements contain a mesogenic control medium which is present in the isotropic phase during operation of the light control elements and arc characterized both by good contrast and low angular field dependence and particularly by very short switching, times. The invention also relates to the mesogenic control media used in the electro-optic light control elements.

Abstract: A method for activating a state transition of a liquid crystal in a liquid crystal display is provided. The liquid crystal display has a first substrate, a second substrate and plural pixel structures, wherein the liquid crystal is sandwiched between the first substrate and the second substrate and each of the plural pixel structures has a transistor having a first electrode and a second electrode. The method including steps of: providing a first potential difference between the first electrode and the second electrode to generate a first electric field; providing a second potential difference between the first substrate and the second substrate to generate a second electric field; and transitioning the liquid crystal from a non-display alignment state to a display alignment state by the first and the second electric fields.

Abstract: The present disclosure includes a method that allows one to obtain high quality alignment of nematic or smectic liquid crystal (LC) polymer glasses in thin films. The present disclosure also includes thin films of aligned smectic or nematic LC main-chain polymer glasses, including aligned chiral smectic C* ferroelectric LC main-chain polymer glasses. The disclosure also includes electro-optical devices, including electro-optical devices comprising aligned chiral smectic C* ferroelectric LC main-chain polymer glasses.

Abstract: The optical element in accordance with the present invention comprises a substrate having a light transmission ability and a fixed liquid crystal layer formed on the substrate. The fixed liquid crystal layer is composed of liquid crystal phase sections in which a liquid crystalline compound is fixed in a liquid crystal phase state and isotropic phase sections in which a liquid crystalline compound is fixed in an isotropic phase state. The layer thickness of the liquid crystal phase sections is larger than that of the isotropic phase sections, and the liquid crystal phase sections are formed so as to protrude with respect to the isotropic phase sections.

Abstract: A liquid crystal is provided, which can be used in a liquid crystal display (LCD) to provide an LCD exhibiting a good transmittance. The liquid crystal according to the invention has the following properties: (i) a dielectric anisotropy (??) ranging from about ?2.5 to about ?5; (ii) a splay elastic constant (K11) ranging from about 1.1×10?11 N to about 1.6×10?11 N; (iii) a bend elastic constant (K33) ranging from about 1.1×10?11 N to about 1.6×10?11 N; and (iv) ??, K11 (N) and K33 (N) conforming to the following equation: K 11 + K 33 ? 10 × ? ? ? ? ? < 1.28 × 10 - 12 . A liquid crystal material combination is also provided which comprises the liquid crystal according to the invention above mentioned and a polymerizable monomer.

Abstract: A display element includes a dielectric material layer 3, provided between a pair of substrates (substrates 1 and 2), which is made of a medium showing optical isotropy when no electric field is applied and showing optical anisotropy when an electric field is applied. Further, comb-shaped electrodes 4 and 5 are provided face to face on the substrate 1 so as to be positioned in a surface which faces the substrate 2. Furthermore, polarizing plates 6 and 7 are respectively provided on rear surfaces with respect to the counter surfaces of the substrates 1 and 2. Thus, it is possible to realize the display element which has a wide driving temperature range, a wide viewing angle property, and a high-speed response property.

Abstract: A blue phase liquid crystalline material comprising a mixture comprising at least one bimesogenic compound and at least one chiral compound, wherein the material is capable of stable existence in the blue phase over a temperature range of at least 5° C. A process for the preparation of the above blue phase liquid crystalline material, an optical device comprising it, a process of mirrorless lasing and a slotted monolithic optical waveguide using it are also disclosed.

Abstract: The present invention discloses a multilayer dielectric optical structure wherein one of the optical materials in the multilayer structure shows an optically isotropic state above and a birefringent state below a characteristic temperature Tc near the room temperature. The optical structure reflects a predetermined wavelength range of electromagnetic radiation above the Tc but allow the same to transmit through below the Tc. The predetermined wavelength can be the near infrared radiation from 700 nm to 2500 nm, and the optical structure rejects solar heat in warm summer days but admits the same to interior on a colder winter day.

Abstract: An in-plane switching mode liquid crystal display device includes upper and lower substrates, first and second ferroelectric liquid crystal layers, a nematic system crystal layer, and first and second electrodes. The electrodes and liquid crystal layers are located between the substrates, with the nematic liquid crystal layer between the ferroelectric liquid crystal layers. The ferroelectric liquid crystal layers have different spontaneous polarization directions. An electric field is applied to the liquid crystal layers using the electrodes. The ferroelectric liquid crystal layers react to different electric field to conduct an in-plane driving of liquid crystal molecules in the nematic liquid crystal layer.

Abstract: A liquid crystal device including a first electrode substrate, a second electrode substrate and a liquid crystal layer is provided. The liquid crystal layer is disposed between the first electrode substrate and the second electrode substrate. The liquid crystal layer comprises liquid crystal molecules and particles. The liquid crystal molecules are vertically aligned when the applied voltage between the first electrode substrate and the second electrode substrate is less than a threshold voltage. The arrangement of the liquid crystal molecules is changed so as to produce optical changes in the liquid crystal device when the applied voltage between the first electrode substrate and the second electrode substrate is not less than the threshold voltage.

Abstract: A display element has a arrangement that allows the pixel to have at least two domains in which the medium shows optical anisotropies of different directions when a force (for example, an electric field) is applied or when no force is applied. It is preferable that directions of the optical anisotropies occurred in the respective domains when the electric field is applied respectively have 45 degrees±10 degrees with absorption axes of polarizers, and that the directions of the optical anisotropies occurred in the respective domains when the electric field is applied make 90 degrees±20 degrees.

Abstract: There is provided a liquid crystal display device in which a direction of an orientation axis of a liquid crystal changes based on an electric field component in a direction different from that of a normal to a principal surface of a substrate, the liquid crystal display device including: a transmitting portion and a reflecting portion disposed on the substrate; wherein a voltage applied to the liquid crystal in the transmitting portion is different from that applied to the liquid crystal in the reflecting portion.

Abstract: A liquid-crystal device includes first and second substrates opposing each other and a liquid-crystal layer held between the first and second substrates. The liquid-crystal device modulates light by switching the orientation of liquid-crystal molecules in the liquid-crystal layer from a splay state orientation to a bend state orientation. The liquid-crystal device further includes a pixel electrode provided for the first substrate; a first opposing electrode provided for the second substrate, an electric field capable of being generated in the liquid-crystal layer between the pixel electrode and the first opposing electrode; and a second opposing electrode provided for the second substrate, an electric field capable of being generated in the liquid-crystal layer at least between the first opposing electrode and the second opposing electrode.

Abstract: A display element of the present invention includes: a pair of substrates at least one of which is transparent; a medium layer, made of a medium sandwiched between the substrates 1 and 2, whose magnitude of an optical anisotropy is changed by applying an electric field; and at least a pair of electrodes applying to the medium layer an electric field which is substantially parallel to the substrates. The electrodes are provided above the substrate via insulating layers each of which is formed in a convex shape. Therefore, a maximal electric field region generated by the electrodes is separated from interfaces of the substrates.

Abstract: The invention relates to a compensated electro-optical light modulation element comprising a mesogenic medium that is operated in an optically isotropic phase of the mesogenic medium and comprising at least one compensation element, and to displays containing such a light modulation element.

Abstract: A method for simultaneously fabricating a phase separated organic film and microstructures with liquid crystal having desired alignment is disclosed. The method includes the step of preparing a mixture of liquid crystal material, prepolymer, and polarization-sensitive material. The mixture is disposed on a substrate and a combination of UV or visible light or heat treatment is applied while simultaneously inducing phase separation so as to form a layer or microstructure of appropriately aligned liquid crystal material adjacent the substrate.

Abstract: A liquid crystal device comprising tilted smectic phases of banana-shaped liquid crystal molecules is disclosed. A method for fabricating a light modulating device is also disclosed. The method comprises the steps of providing a pair of substrates with a cell gap therebetween and permanently disposing at least one banana-shaped liquid crystal material into said cell gap. The present invention also provides a method of generating an image, comprising providing a pair of substrates with a cell gap therebetween, providing transparent electrodes on each of the substrates adjacent to the cell gap, disposing at least one banana-shaped liquid crystal material into the cell gap; and applying an electric field across the electrodes. The tilted smectic phases of banana-shaped liquid crystal may be in either a racemic or a chiral state.

Abstract: Disclosed is a liquid crystal display apparatus comprising a pair of substrates and a liquid crystal layer provided between the substrates, the liquid crystal layer containing a liquid crystal composition that exhibits a cholesteric phase. The liquid crystal composition contains a mixture of a chiral material and nematic liquid crystal. The liquid crystal display layer is configured to satisfies the following conditions: a viscosity a [cP] of the liquid crystal composition is in a range from 30 to 150; a dielectric anisotropy b of the liquid crystal composition is in a range from 5 to 50; a thickness c [?m] of the liquid crystal layer is in a range from 3 to 8; and a product of a, b, and c is not less than 3500.

Abstract: A display includes a front panel and a back panel with a light control material in between. One of the panels includes a rigid substrate, for example made of glass or rigid plastic. The other of the panels includes a flexible substrate, for example made of a flexible plastic film. The panel with the flexible substrate may be made by a roll-to-roll process, with various fabrication operations formed while the flexible substrate is still part of a web of material. The panel with the rigid substrate may be separately fabricated, then combined with the other panel on the web through a pick and place operation that accurately locates the front panel relative to the back panel. The display may be any of a variety of displays, such as liquid crystal displays (LCDs), and electroluminescent displays, such as polymer light emitting devices (PLEDs) and organic light emitting devices (OLEDs).

Abstract: In a monostable ferroelectric active matrix display comprising a liquid-crystal layer in the form of a monodomain having an unambiguously defined direction of the layer normals z of the smC* phase, the layer normals z and the preferential direction n of the nematic or cholesteric phase (N* phase) form an angle of more than 5°.

Abstract: The object of the present invention is to provide a novel liquid crystal display material having an excellent contrast ratio, a display method and a display device using the material. The present invention uses a liquid crystal display material comprising a polymer in which a liquid crystal is dispersed in a dissolvable state or a phase separable state, wherein the liquid crystal dissolves in the polymer at high temperatures and separates from the polymer at low temperatures, and a contrast ratio (B/A) of a reflectance (A) of the display material cooled from the dissolution state at a rate of 10° C./sec and a reflectance (B) of the display material cooled from the dissolution state at a rate of 4° C./sec is not less than 2. The image forming state can be maintained by controlling the cooling rate from the dissolution state to maintain the liquid crystal in translucent state.

Abstract: A liquid crystal device is constituted by a chiral smectic liquid crystal to form a plurality of pixels. The chiral smectic liquid crystal has a temperature-dependent tilt angle characteristic satisfying the following relationship: Ĥ10−Ĥ1≦4.0 degrees, wherein Ĥ10 denotes a tilt angle at a temperature which is 10° C. lower than an upper limit temperature of chiral smectic C phase and Ĥ1 denotes a tilt angle at a temperature which is 1° C. lower than the upper limit temperature.

Abstract: A liquid crystal device comprises plural pixel electrodes arranged in a matrix form, a common electrodes facing the pixel electrodes, a liquid crystal layer sandwiched therebetween, and plural switches to drive the respective pixel electrodes. A reflectivity or transmittance of the liquid crystal varies according to a first state where a direction of a normal to each of the liquid crystal is the same, a second state where the above direction of the normal is at random, and a third state where a spiral structure of the liquid crystal is untied, and has a hysteresis characteristics with respect to an applied voltage including an insensitive voltage region where a reflectivity or transmission state is not determined by the applied voltage. The device has an operation such that the applied voltage is brought into the insensitive voltage region, after a display signal is written into the pixel electrode, to hold the display state.

Abstract: Driver apparatus and methods of driving at least a portion of a cholesteric liquid crystal ("CLC") panel to a state having a given reflectivity. One of the methods includes the steps of: (1) initially driving the portion to a nematic phase, (2) subsequently driving the portion to a cholesteric phase focal-conic state, the cholesteric phase focal-conic state providing a known reference state for subsequent driving of the portion and (3) thereafter driving the portion to the state having the given reflectivity.