The present invention addresses the problem of providing a nursing wheelchair, comprising a seat member which deploys on a frame body to form a seat. The nursing wheelchair readily allows transfer of a person receiving care, and is lightweight and easy to operate. A nursing wheelchair (1) comprises seat members (7a, 7b) which deploy on seat support frames (14a, 14b) constituting part of a frame body (2) in order to form a seat.

A system and method for adjusting the arms of an over-sized trailer is described herein. In one embodiment, the system can comprise a center support, a plurality of swing arms, and a plurality of stabilizer rods. The swing arms can be mounted to the left side and the right side of the center support. The swing arms can each comprise an arm and an arm hinge. The swing arms can be capable of rotating about the arm hinge. Furthermore, a dolly can be capable of being mounted to each swing arms. Each of the stabilizer rods can comprise a first rod portion and a second rod portion. The first rod portion can be connected to the center support and the second rod portion connected to one of the swing arms.

A gliding apparatus includes a gliding board, a first front boot-retaining device for ascending a slope and a second front boot-retaining device for the descent. The first front retaining device comprises a first boot-fastening mechanism, defining a boot pivot axis during the ascent. The second front retaining device comprises a second boot-fastening mechanism, including a movable element incorporating an interface surface capable of contacting a front portion of the boot, the movable element being separate from the first fastening mechanism. The second front retaining device is configurable in a first “inactive” configuration for which the interface surface is away from the boot front portion, and a second “active” configuration for which the interface surface contacts the boot front portion. The first boot-fastening mechanism is capable of cooperating with the movable element of the second front retaining device so as to maintain the second front retaining device in its active configuration.

The present invention relates to a swim chair that allows a mobility challenged individual to be transported across the sand with exceptional ease, to lounge on the chair and enjoy the company and sights, to be pulled into the water and, if able, to slip off the chair to go for a swim, remount the chair and return to shore. The chair includes a main frame, defined by a top frame member and two side frame members; two axle support plates, at or in communication with the side frame members of the main frame, the axle support plates having a plurality of openings to receive a wheel axle and optionally a pull rod axle; a wheel assembly; a drop seat; a footrest and a backrest.

An airbag system for protecting rear seat occupants in dynamic side impacts using an improved packaging arrangement is provided. The system includes seat base and seat back frames. The seat back frame is movable between an upright position and a reclined position. The system further includes a unified airbag having a pelvic portion and a thoracic portion. The pelvic portion is positioned adjacent to the seat base frame. The thoracic portion is positioned adjacent to the seat back frame. The unified airbag is attached to the seat base frame by fixed anchors and to the seat back frame by a movable anchor. A grooved track is provided for attachment of the movable anchor. The airbag may be a strip shape or a triangular shape. One or more tethers may be attached to the unified airbag.

Interior panels having integrated airbag doors for motor vehicles and methods for making such interior panels are provided herein. In one example, an interior panel comprises a substrate having outer and inner surfaces and an opening extending therethrough. A multi-shot injection molded airbag chute-door assembly is mounted to the substrate and comprises a chute wall that at least partially surrounds an interior space. A door flap portion is pivotally connected to the chute wall and at least partially covers the opening. A perimeter flange extends from the chute wall and has a flange section that overlies the outer surface of the substrate. A molded-in lip feature extends from the flange section and contacts the outer surface to form a seal between the flange section and the substrate. A skin covering extends over the substrate and a foam is disposed between the skin covering and the substrate.

In an inflated and expanded state of a side airbag, a forwardly extending portion, provided at an upper portion of a rear side bag portion, extends from a side of a shoulder portion of a seated passenger toward a vehicle front side and is disposed above a front side bag portion. A dimension in a vehicle transverse direction of this forwardly extending portion is set to be smaller than that of the front side bag portion, and a vehicle transverse direction inner side surface at an upper end side of the front side bag portion is inclined or curved so as to rise-up while heading toward a vehicle transverse direction outer side. An upper arm portion is pushed-up due to sliding contact with this surface. Even when the seated passenger inertially toward an oblique front of a vehicle, the shoulder portion can be restrained by the forwardly extending portion.

Aspirator for an airbag deploying into a vehicle passenger compartment in order to protect a driver of the vehicle during an accident, includes a housing having an innermost and an outermost wall and defining an outlet at a distal end leading to an airbag and coaxial flow passages between the innermost and outermost walls into which air from a passenger compartment flows to inflate the airbag. An aspiration system is coupled to the housing and configured to direct gas into the flow passages to mix with the air from the passenger compartment in the flow passages. The aspiration system includes openings on an inner side of the outermost wall and on an outer side of the innermost wall. These openings are configured such that the gas is directed therefrom into the flow passages in a direction substantially parallel to a flow direction of air into the flow passages.

An airbag apparatus for vehicle includes: an airbag body formed by joining outer peripheral portions of two base cloths, the two base cloths being superimposed on each other; an inflator introducing gas to an inside of the airbag body; and a vent hole formed on the airbag body and configured of a slit, the vent hole communicating between the inside and an outside of the airbag body, the slit being formed so as to be directed from the outer peripheral portions toward central portions of the two base cloths over the two base cloths.

Airbag inflator system includes an inflatable airbag, e.g., a side curtain airbag, a housing, a gas generating system arranged apart from the housing for generating gas, and a conduit leading from the gas generating system to the housing to provide gas to the housing, e.g., to a lateral end of the housing. A filter may be arranged between the gas generating system and the housing, possibly in the conduit. A nozzle may be arranged between the gas generating system and an interior of the airbag, which nozzle is varied as a function of temperature. The housing may be movably arranged relative to a fixed base and mounted to vary its relation to the base as a function of temperature, e.g., via elastic or deformable supports which support the housing on the base.

A lightweight folding motorized chair with mechanical traction steering and braking. A folding frame supports the traction wheels and the drive system with hinged frame members configured to mechanically fold the control levers, wheels and periphery components into a substantially flat configuration for easy storage in small spaces. A mix of weight saving choices including: structural materials; mechanical traction control system; lithium ion battery; and overall lightweight design keeps the folding motorized chair at a size and weight that a person can lift into the trunk of a car.

A deployment guiding cloth is wound from an outside in the vehicle width direction, on an outer peripheral portion of a folded side airbag. This deployment guiding cloth extends toward a vehicle front side and is interposed between the side airbag that is partially deployed and a vehicle cabin side portion (a center pillar garnish and a door trim) before the side airbag is fully deployed.

A pre-weakened cover of an airbag module is provided including a layer having an outer show surface and an opposing inner surface. A plurality of first cuts is arranged at a first angle on the inner surface. A plurality of second cuts is arranged at a second angle on the inner surface. Each of the second cuts intersects two adjacent first cuts to form a generally V-shaped pattern.

A pre-weakened cover of an airbag module is provided including a layer having an outer show surface and an opposing inner surface. A plurality of first cuts is arranged at a first angle on the inner surface. A plurality of second cuts is arranged at a second angle on the inner surface. Each of the second cuts intersects two adjacent first cuts to form a generally V-shaped pattern.

A driver seat airbag system includes: an airbag that is housed in a pad section of a steering wheel, receives a supply of gas for inflation during a collision of a vehicle, and is inflated and deployed between the steering wheel and an occupant in a driver seat; and an inflator that generates the gas. The airbag includes an auxiliary inflated section that is inflated to a front of the vehicle in conjunction with inflation and deployment of the airbag, so as to enter a space between a rim and a spoke of the steering wheel.

Embodiments of the invention relate to polycrystalline diamond compacts (“PDCs”) comprising a polycrystalline diamond (“PCD”) table including at least a portion having aluminum carbide disposed interstitially between bonded-together diamond grains thereof, and methods of fabricating such PDCs. In an embodiment, a PDC includes a substrate, and a PCD table bonded to the substrate. The PCD table includes a plurality of bonded-together diamond grains defining a plurality of interstitial regions. The PCD table further includes aluminum carbide disposed in at least a portion of the plurality of interstitial regions.

There is provided a cassette having: a flexible accommodating body that accommodates an accumulative fluorescent sheet in a light shielded state; an entrance/exit portion that is provided at one end portion of the flexible accommodating body, and through which the accumulative fluorescent sheet can be inserted and removed into and from the flexible accommodating body due to mounting to a radiographic image reading device; and opening/closing means for opening the flexible accommodating body such that a push-out member, that pushes the accumulative fluorescent sheet out toward the entrance/exit portion, can be inserted, or closing the flexible accommodating body in a light shielded state.

An airflow-organization testing method for a clean room and a system using the same method are disclosed. The airflow-organization testing method for a clean room uses a thermal imaging device to detect a sample gas-flow formed by a sample gas in the clean room, and the sample gas has a temperature difference from ambient air. The airflow-organization testing system for a clean room includes a sample gas supplier and a thermal imaging device, and the thermal imaging device can continuously detect a spatial position of the sample gas and display it on a display, thereby improving detection precision and expanding detection range.

The present invention provides grain-drying facilities which can effectively use the heat energy of a biomass combustion hot-air that has been generated in a biomass combustion furnace. The grain-drying facilities adopt technical means of providing the grain-drying facilities 1 which include: a biomass combustion furnace 3 provided with a heat exchanger 24 for generating hot air on the basis of a combustion heat of a biomass fuel and an outside air which has been taken in from the outside; and a circulation type grain-drying apparatus 2 provided with a grain-drying portion 7 to which the hot air that has been generated in the biomass combustion furnace 3 is supplied through a pipe 15 for supplying the hot air, wherein the above described circulation type grain-drying apparatus 2 has a grain-heating portion 6 which has a plurality of heating pipes 6a for heating the grains in the above described grain storing/circulating tank 5, and also has an air-exhaust fan 14 that is communicated with an exhaust side opening 6c that is located in one end side of each of the heating pipes 6a, and has a pipe 11 for supplying an exhaust hot-air, which communicates the exhaust hot-air sent from the above described biomass combustion furnace 3 with a supply side opening 6b that is located in the other end side of the heating pipe 6a.

A carbon fuel combustion process, employing an air gas separation unit, a combustion unit operating either with air or with an oxidizer leaner in nitrogen than air, coming from the air gas separation unit, and a unit for compressing and/or purifying the CO2 coming from the combustion flue gas, wherein the power consumed by the air gas separation unit and/or the flow of oxygen produced by the air gas separation unit and/or the capture of the CO2 coming from the combustion flue gas are variable over time is presented.

Apparatus and methods are disclosed for rapidly counteracting a transient low-pressure condition, that can occur intermittently in the exhaust section of a power plant or other such industrial facility upstream of exhaust fans as a result of an event that interrupts the generation and/or flow of exhaust gases, using jet nozzles disposed in the exhaust section and connected to a source of pressurized air or other suitable momentum material. By orienting the jet nozzles in a direction generally opposite to the flow of exhaust gas and actuating the system to release a burst of compressed air, for example in the event of a power plant interruption, the low-pressure condition can be ameliorated preventing damage to the exhaust section.

A premix burner arrangement for safely oxygen-enriching a premix air-fuel combustion system is disclosed. In the disclosed burner arrangement, a first conduit is arranged and disposed to provide a first gas stream. The first gas stream is a self-reactive or self-flammable premixture comprising air and a combustible gas. At least one second conduit is arranged and disposed to provide a second gas stream circumferentially around the first gas stream. The second gas stream includes oxygen. The premix burner arrangement is configured to combust or react the first stream at a temperature at least 1000° F. greater than the temperature of the second stream. A method and combustion system including the premix burner arrangement are also disclosed.

Improved silicon solar cells, silicon image sensors and like photosensitive devices are made to include strained silicon at or sufficiently near the junctions or other active regions of the devices to provide increased sensitivity to longer wavelength light. Strained silicon has a lower band gap than conventional silicon. One method of making a solar cell that contains tensile strained silicon etches a set of parallel trenches into a silicon wafer and induces tensile strain in the silicon fins between the trenches. The method may induce tensile strain in the silicon fins by filling the trenches with compressively strained silicon nitride or silicon oxide. A deposited layer of compressively strained silicon nitride adheres to the walls of the trenches and generates biaxial tensile strain in the plane of adjacent silicon fins.

Methods and apparatus for converting electromagnetic radiation, such as solar energy, into electric energy with increased efficiency when compared to conventional solar cells are provided. A photovoltaic (PV) device generally includes a window layer; an absorber layer disposed below the window layer such that electrons are generated when photons travel through the window layer and are absorbed by the absorber layer; and a plurality of contacts for external connection coupled to the absorber layer, such that all of the contacts for external connection are disposed below the absorber layer and do not block any of the photons from reaching the absorber layer through the window layer. Locating all the contacts on the back side of the PV device avoids solar shadows caused by front side contacts, typically found in conventional solar cells. Therefore, PV devices described herein with back side contacts may allow for increased efficiency when compared to conventional solar cells.

Disclosed is a photovoltaic device. The photovoltaic device includes: a substrate; a first electrode placed on the substrate; a second electrode which is placed opposite to the first electrode and which light is incident on; a first unit cell being placed between the first electrode and the second electrode, and including an intrinsic semiconductor layer including crystalline silicon grains making the surface of the intrinsic semiconductor layer toward the second electrode textured; and a second unit cell placed between the first unit cell and the second electrode.

This invention is directed to a flexible solar cell photovoltaic module with high light transmittance based on modified substrate, which belongs to the field of thin-film solar cell technology. The objective of the present invention to provide a technical solution for a transparent flexible solar cell module and its fabrication method. Technical features include using a stainless steel template to mold a modified polyimide PI substrate (the PI substrate). The PI substrate has light-passing through-holes, including draining holes and convergence holes, through and distributed on the PI substrate, a conductive film layer, and various stacked photoelectric conversion film layers. The creativeness of the present invention is obvious, such as reducing the short circuit and current leakage due to crystallization of the photoelectric layer interface caused by a subsequent process of laser etching the conductive film layer, reducing the composition on the surface of the solar cell, reducing steps of the fabrication process, and lowering the production cost. Further, the present invention significantly increases the conversion efficiency and load capacity of the solar cell and the quality-cost ratio. The transparent flexible solar cell photovoltaic module also has a broad range of applications.

A resin composition, a multi-layered film, a backsheet for photovoltaic modules, a method thereof, and a photovoltaic module are provided. The multi-layered film including a coating layer including a fluorine-based polymer has an excellent durability and weather resistance, and also exhibits high interfacial adhesive strength to a substrate since the multi-layered film is formed by coating a cured product of the resin composition including the fluorine-based polymer, an acrylic polymer including a thermosetting functional group, and a heat-curing agent on the substrate. In addition, drying can be performed at a low temperature during the manufacture of the multi-layered film so that the manufacturing costs can be decreased, productivity can be increased, and the deterioration of the product due to heat modification, heat shock, and the like, can be prevented. The multi-layered film can be effectively used as a backsheet for various photovoltaic modules.

Novel photoactive polymers, as well as related photovoltaic cells, articles, systems, and methods, are disclosed.

An organic compound and a photoelectric conversion device containing the organic compound are disclosed. The organic compound and device realize high photoelectric conversion efficiency, low dark current and high-speed responsivity. It has been found that when this organic compound and an n-type semiconductor are used in combination, high-speed responsivity can be realized while maintaining high heat resistance, an aspect of which has not been seen when the connection part between a donor part and an acceptor part is a phenylene group.

A PV panel uses an array of small silicon sphere diodes (10-300 microns in diameter) connected in parallel. The spheres are embedded in an uncured aluminum-containing layer, and the aluminum-containing layer is heated to anneal the aluminum-containing layer as well as p-dope the bottom surface of the spheres. A phosphorus-containing layer is deposited over the spheres to dope the top surface n-type, forming a pn junction. The phosphorus layer is then removed. A conductor is deposited to contact the top surface. Alternatively, the spheres are deposited with a p-type core and an n-type outer shell. After deposition, the top surface is etched to expose the core. A first conductor layer contacts the bottom surface, and a second conductor layer contacts the exposed core. A liquid lens material is deposited over the rounded top surface of the spheres and cured to provide conformal lenses designed to increase the PV panel efficiency.

The present invention provides a photoelectric conversion material comprising a fullerene derivative represented by the formula C60(R1)5(R2), wherein each R1 independently represents an organic group having a substituent; and R2 represents a hydrogen atom or a substituted or unsubstituted C1-C30 hydrocarbon group. Further, the present invention also provides a photoelectric conversion device having a self-assembled monomolecular film of the photoelectric conversion material, and a solar cell having the photoelectric conversion device.

A method for fabricating a photovoltaic device includes depositing a p-type layer at a first temperature and depositing an intrinsic layer while gradually increasing a deposition temperature to a final temperature. The intrinsic layer deposition is completed at the final temperature. An n-type layer is formed on the intrinsic layer.

A photovoltaic cell comprises a top subcell having a first band gap; a middle subcell comprising a substrate and having a second band gap, wherein the substrate comprises a first side and a second side opposite to the first side; and a bottom subcell having a third band gap, wherein the top subcell is grown on the first side of the substrate and the bottom subcell is grown on the second side of the substrate, wherein the first band gap is larger than the second band gap and the second band gap is larger than the third band gap.

A photovoltaic device including a substrate; a first electrode placed on the substrate; a second electrode which is placed opposite to the first electrode and which light is incident on; a first unit cell being placed between the first electrode and the second electrode, and including an intrinsic semiconductor layer including crystalline silicon grains making the surface of the intrinsic semiconductor layer toward the second electrode textured; and a second unit cell placed between the first unit cell and the second electrode.

A surface of a photovoltaic cell is coated with a solution that includes barium titanate to reduce reflection of sunlight that is incident on the surface. The solution may include a base of polydimethylsiloxane and carbon nanotubes. The process may be used in the fabrication of new photovoltaic cell assemblies, or to retrofit existing assemblies in situ.

Methods of forming a photovoltaic structures including nanoparticles are disclosed. The method includes electrospray deposition of nanoparticles. The nanoparticles can include TiO2 nanoparticles and quantum dots. In an example, the nanoparticles are formed on a flexible substrate. In various examples, the flexible substrate is light transparent. Photovoltaic structures and apparatus for forming photovoltaic structures are disclosed.

The invention relates to a packaging machine, in particular a thermoformer, traysealer, comprising at least two transport chains for transporting a web of material, such as a film or the like. The packaging machine is characterized in that sensor means are provided for detecting the chain length and/or the chain pitch and/or the chain tension of the transport chains, means being provided for stretching and/or relaxing at least one individual transport chain, and control means being provided for adapting different lengths or chain pitches of two transport chains by stretching and/or relaxing at least one transport chain in a controlled manner.

A phase-locked loop double-point modulator may include a frequency divider having a ratio which can be changed by a first modulation signal, and an oscillator, a frequency of which can be changed by a second modulation signal correlated to the first modulation signal. A calibration circuit may be configured, in a calibration mode, to match the gains of the first and second modulation signals based on frequency measurements of the oscillator for two different calibration values of the second modulation signal. The phase-locked double-point modulator may also include an attenuator having a constant ratio greater than 1 and placed in the path of the second modulation signal, and a selector switch configured to be controlled by the calibration circuit to reduce the ratio of the attenuator in the calibration mode.

A rail-to-rail comparator including a first comparison unit connected to a first terminal and configured to compare differential input signals to differential reference voltages; a second comparison unit connected to a second terminal and configured to compare the differential input signals to the differential reference voltages; and an output unit configured to be driven in response to a clock signal and to generate a complementary output signal according to comparison results of the first and second comparison units.

A method for generating/transmitting a transmission-unit symbol sequence is disclosed. In the case of transmission information, the information is modulated in time and frequency domains on the basis of a predetermined transmission unit (e.g., a transmission time interval TTI or slot), simultaneous transmission of the information is made, and then a transmission unit symbol is generated/transmitted. A transmission sequence is masked in each symbol contained in one transmission unit. Symbol-unit circular shift (cyclic shift) is applied to the masked result, so that transmission efficiency increases. A control signal transmission method for supporting a variety of formats and a signal transmission method based on a prime-length sequence are also provided.

An arc extinguishing apparatus for a ring main unit includes: a housing; a plurality of fixed contactor assemblies fixed to be protruded toward the center in the housing and formed by inserting a permanent magnet for arc extinguishing by a magnetic force between a pair of main circuit fixed contacts; a plurality of earthing fixed contactors fixed to be protruded toward the center in the housing and installed to be spaced apart from the fixed contactor assemblies at a predetermined angle; a 3-phases common rotational shaft installed to be rotatable at the center of the housing; and a rotatable movable contactor assembly having a plurality of puffer guide plate sections having openings with a narrow opening width to accelerate the velocity of flow of insulating gas to extinguish arc by blowing it, and rotatable to a circuit closing position, an earthing position, and a circuit opening position.

An arc guider configured to provide an arc movement path, one side thereof forming a fixation projection and a center thereof forming a groove in a longitudinal direction, a fixation element sequentially including a main contact, an arc contact being spaced apart from the main contact and an insertion groove accommodating the arc guider and a plurality of projection fixing units being formed on both sides of the insertion groove and being curved toward the accommodated arc guider through an outer force so that the fixation projection does not escape wherein triangle V shaped groove marks by the outer force are formed in the plurality of the projection fixing units.

A food container stacking device comprising: a horizontal member, with a first longitudinal side, a second longitudinal side, a top surface, and a bottom surface, a first corner, second corner, third corner, and fourth corner; the food container stacking device configured to lay on the top surface of a first food container, and further configure to support a second food container on the top surface, thereby allowing for the stacking of the first and second food containers. A food container stacking system, comprising: a first food container; a first food container stacking device configured to lay on the top surface of the first food container, the first food container stacking device comprising: a horizontal member, with a first longitudinal sinusoidal shaped side, a second longitudinal sinusoidal shaped side, a top surface, and a bottom surface, a first corner, second corner, third corner, and fourth corner; a first pin removeably attachable to the first hole, and extending from the bottom surface; a second pin removeably attachable to the second hole, and extending from the bottom surface; a third pin removeably attachable to the third hole, and extending from the bottom surface; a fourth pin removeably attachable to the fourth hole, and extending from the bottom surface, where the first and second pins are configured to lay outside of the perimeter of the first food container, and where the third and fourth pins are configured to lay outside of the perimeter of the first food container, on an opposite side of the first food container.

Container assemblies can include a first container and a second container, where the second container extends into and is supported by the first container. The first container and the second container can each include a flange around the periphery of an access opening. The flange of the second container is configured to provide support for the second container via engagement with the flange of the first container. In some instances, the second container can extend into and be supported by the first container through engagement of the flange of the second container with the flange of the first container such that a side panel of the first container is not in contact with a corresponding side panel of the second container. The container assembly can also include a lid for retaining the second container in the first container and/or for sealing to the first container and/or the second container.

Protective mailer capable of being processed by postal processing equipment without causing damage to the article held by the mailer. The pocket holding the article inside the mailer is offset relative to one edge, when folded, by a distance sufficient to prevent damage when the mailer is oriented and processed. The mailer may include a resizing flap that, when unfolded and deployed, changes the dimensions of the mailer so that the mailer is processed by the postal processing equipment as a non-letter or flat mailpiece.

A bottled drink includes a cap and a bottle where a granular supplement containing multiple constituents in a stable manner is stored in the cap and a solution suitable for dispersing the granules is filled in the bottle. Granules which contains mutually incompatible multiple chemical agents or nutritional constituents and whose surface is coated with polyglyceryl fatty acid ester are stored in the cap of the bottle and the bottle is filled with a solution whose viscosity at a shear deformation speed of 0.01 s−1 is 10 to 300 Pa·s.

A container has a base and walls connected to the base to define an interior space. The walls have upper edges that terminate in a plane and define an opening for access to the interior space. Wetted donnable articles are stacked within the container, each article in a flat configuration at least partially perpendicular to the opening permitting withdrawal of any one of the donnable articles through the opening in a flat configuration. Walls on opposing sides of the base of the container diverge from each other with increasing distance from the base, such that the interior space widens gradually toward the opening. Walls on other opposing sides of the base have lower portions connected to the base and upper portions connected to the lower portions by steps that lengthen the interior space abruptly.

The present invention relates to utility surfaces. Specifically, the invention relates to a utility surface, generally a table or other flat surface, with drawers attached to the utility surface. In preferred embodiments of the present invention, the utility surface and attached drawers may be folded into a collapsed format that is convenient for portability.

Containers and components thereof for use in the medical industry and methods to manufacture the same are described. An example tab for use with a medical container includes opposing sheets sealed to define an open ended chamber into which a port is to be at least partially positioned. The port is to enable access to the medical container. The tab includes a tear seal defined by each of the opposing sheets and a first guide positioned on a first side of each of the tear seals. The tab includes a second guide positioned on a second side of each of the tear seals, wherein the first and second guides are to enable a tear to propagate substantially between the guides and adjacent the tear seals.

A container (10) for consumer goods comprises a first panel (16) having a pattern (22) applied to an area (20) of the external surface thereof; and a second panel (26) comprising a transparent optical element. The first panel (16) and the second panel (26) are moveable relative to each other between a first position, in which the transparent optical element in the second panel (26) does not overlie the pattern (22) on the first panel (16), and a second position, in which the transparent optical element in the second panel (26) at least partially overlies the pattern (22) on the first panel (16), whereby an altered image of the pattern is visible through the transparent optical element.