Abstract: A seat belt apparatus includes a reel, a motor, a clutch member, a belt reacher, a door opening/closing detection section, a wearing detection section and a motor control section. Once a change from an opened state to a closed state of a vehicle door is detected by the opening/closing detection section, the control section controls the motor so that the webbing is pulled out from the reel at a predetermined speed. Once wearing of the webbing is detected by the wearing detection section while the webbing is being pulled out at the predetermined speed, the control section controls the motor to stop pulling-out of the webbing. The predetermined speed is first kept at a constant speed, corresponding for example to a 10[%] duty cycle, for a predetermined time period and then caused to gradually decrease from the constant speed.

Abstract: A first yarn feeder is provided with a drum which has a plurality of yarn loops wound thereon and is driven to rotate by a respective motor. The motor is electronically connected to a textile machine for rotating at a speed proportional to the yarn-drawing speed of the textile machine and delivering the yarn wound on the drum to the latter. A second feeder is arranged to draw the yarn from a reel and to deliver it to the first feeder, with a delivery action which is modulated by a control loop. The latter is programmed to stabilize the tension of the yarn unwinding from the second feeder on a predetermined value on the basis of a signal received from a tension sensor operatively coupled to the yarn.

Abstract: A device for facilitating the efficient and even quilt binding finishing is described. The device comprises: a base member, rod member and spool member.

Abstract: A drum assembly having a post, and first and second spoke frames. Each of the first and second spoke frames includes expandable spokes and immovable spokes, extending away from the post. Each expandable spoke includes a distal end movable between a retracted position and an extended position. A plurality of first drum segments each are mounted to the distal end of one of the expandable spokes of the first spoke frame and to the distal end of one of the expandable spokes of the second spoke frame. A plurality of second drum segments each mounted to an end of one of the immovable spokes of the first spoke frame and to an end of one of the immovable spokes of the second spoke frame. Mechanical actuators, extending between the post and either the expandable spokes or the first drum segments, move the expandable spokes between the retracted and extended positions.

Abstract: Spooling machine including two side frames spaced at a horizontal distance by a telescopic spacer beam, each frame having a pintle on supports for bearing a drum for cable pipe or hose, the telescopic spacer beam including at least one outer tube and at least one inner tube, which are slidably and telescopically one inside the other, and a locking device positioned between the outer tube and the inner tube for locking the outer and inner tube in adjustable position. The locking device includes a split part of the inner tube extending over a part of the length of the inner tube and dividing the inner tube into sections, and a force element for creating a swelling force on the split part of the inner tube to press the sections against the inner surface of the outer tube.

Abstract: A system, an apparatus, and a method for an aerospace vehicle braking system for decelerating an aerospace vehicle on a landing surface. An arm is provided having a first portion connected to the aerospace vehicle and a second portion generally distal to the first portion. The second portion of the arm includes an engagement portion configured to engage the landing surface. The arm is movable between a first position, wherein the engagement portion is substantially disengaged from the landing surface, and a second position, wherein the engagement portion engages the landing surface with a force sufficient to significantly decelerate the aerospace vehicle. The engagement portion is configured to pivot with respect to the arm in response to the direction of travel of the aerospace vehicle upon the landing surface. An actuator is connected to the arm to selectively move the arm between the first position and the second position.

Abstract: According to one embodiment, a clutch may be coupled between a rotor system and a power train of a rotorcraft. The clutch may be operable to disengage the rotor system from the power train during operation of the power train. A clutch control system in communication with the clutch and include a rotorcraft condition sensor operable to sense an operating condition of the rotorcraft and a control unit operable to prevent the clutch from disengaging the rotor system from the power train if the operating condition of the rotorcraft fails to satisfy a predetermined criterion.

Abstract: The invention proposes to protect a rear part of a floor of an aft fairing of a pylon of an aircraft bypass turbojet engine using a film of cool air formed of part of a bypass flow of the jet engine which is guided under the floor by two lateral wall portions of this fairing which have been profiled for this purpose. To do that, these two lateral wall portions delimit respective air passage spaces formed between a forward part of the floor and a jetpipe of the turbojet engine and which open laterally and towards the rear.

Abstract: A seat base for use in aircraft has a first cross member, a second cross member, a first leg, a second leg, and a base plate having a first bendable tab and a second bendable tab facing away from the first tab. The first cross member, the second cross member, and the base plate are each configured to be secured to the first and second legs in an extended position and a retracted position. The first and second legs are configured to be secured to seat feet and floor tracking rails. The first and second cross members are secured to the base plate so as to allow for selective rotation of the first and second cross members in response to relative vertical movement of the first leg with respect to the second leg.

Abstract: The present invention relates to a de-icing arrangement for de-icing a structural element {170; 270; 370). The structural element could be made of a whole polymeric or metallic material. The arrangement comprises a power source (250) being electrically connected to an electrode configuration (200), said power source is arranged to, when applicable, electrically charge said electrode configuration (200). The electrode configuration (200) is arranged to generate an impulsive force (Fn) for removal of ice adhered on said structural element (170; 270; 370). The invention relates to a method for de-icing a structural element. The invention also relates to a computer programme and a computer programme product. The invention also relates to a platform carrying the arrangement.

Abstract: An ice protection system (20) comprising an electrothermal device (30) responsible for maintaining an aircraft surface (14) at an anti-ice temperature greater than 0° C. An optimum power input to the electrothermal device (30) is based on outside air temperature sensed by an OAT sensor (30) and on liquid water content detected by an LWC detector (50). The system (20) can be preferably characterized by the absence of surface-temperatures sensors.

Abstract: A method for deicing an aerostructure includes driving a sensing current through a heater element coated to an aerostructure, the heater element having a resistance that is temperature dependent. A resistance of the heater element is monitored. It is determined whether there is icing at the heater element using the monitored resistance of the heater element. A melting current is driven through the heater element when it is determined that there is icing at the heater element.

Abstract: An outer fuel access tank cover (FTAC) of an aircraft, a wing comprising such outer FTAC of an aircraft and an aircraft are provided. In one example, an outer fuel tank access cover (FTAC) (4) of an aircraft includes an inner surface and an outer surface. The outer FTAC is to cover the outer opening of a void area of a manhole for accessing the interior of a wing of an aircraft in which the interior of the wing comprises a fuel tank. The outer FTAC comprises absorption means adapted for absorbing the impact energy due to an object impacting against the outer FTAC.

Abstract: Unique aeroplane wing profiles substantially increasing the aerodynamic qualities of the wing are proposed. The advantage of the proposed profiles and novel method for forming lifting force for a wing on the basis of said profiles is the complete shifting of the interaction of the windstream onto the lower contour, the complete liberation of the upper contour from interaction with the windstream, leading to the elimination of wave drag—an insurmountable defect in wings with a classic profile, and a substantial increase in lifting force for the wing. Novel solutions are given which were the basis for a basically novel interpretation of the process of flow around a wing by the windstream and of the formation of excess pressure along the lower surface.

Abstract: An aircraft is provided with a mechanical linkage that mechanically transmits an amount of manipulation of a control stick to a rudder controlling mechanism, an amount-of-manipulation sensor that detects the amount of manipulation, and an FBW control-law computing unit that calculates an FBW control-law command indicating an amount of control for a craft in accordance with the detected amount of manipulation. Also, with the aircraft, a high-pass filter outputs, among the control-stick manipulation amounts detected by the amount-of-manipulation sensor, an amount of change in the control-stick manipulation amounts; by subtracting the amount of change that has passed through the high-pass filter by means of the subtracting portion, the FBW control-law command serves as an SAS command; and the rudder controlling mechanism is driven by adding an amount of movement of an SAS actuator in accordance with the SAS command to the control-stick manipulation amount transmitted by the mechanical linkage.

Abstract: A vertical take off and landing (VTOL) aircraft is designed to be so efficient that it can be commercially competitive with runway dependent aircraft operating in a range of 100 to 1000 miles. Improvements include a high efficiency tilting rotor and wing design that enable both vertical takeoff and efficient high speed cruising, a high aspect ratio wing, and a variable speed propulsion system that is efficient in both hover and cruise flight. Preferred aircraft use thin inboard and outboard wings, thin rotor blades, and use efficient lightweight design to achieve unusually low empty weight fraction. Inventive methods include utilization of advanced design and analysis techniques, which allow for accurate prediction of an aircraft's physical behavior.

Abstract: A device and a method operate decentralized functional units arranged in an industrial installation. The device contains a superordinate control system which interchanges information with the decentralized functional units using data messages, and a data transport network having a number of network access points. The superordinate control system is coupled to the data transport network via at least one network access point. The device further has communication units which are connected to a network access point and provide the decentralized functional units with access to the data transport network, and an energy transport network to which the decentralized functional units are connected and which supplies the decentralized functional units with electrical energy. A number of intelligent energy stores are connected to the energy transport network and consume energy and/or output energy in accordance with the super ordinate control system and/or at least one of the other energy stores.

Abstract: A method operates a railway safety system having at least one trackside device while taking into account a measured velocity value recorded when the rail vehicle drives into a switch-on section of the railway safety system. In order to minimize the closing times for a level crossing by such a method, the measured velocity value is used as the basis for checking whether a correction time for forwarding a signal from the one trackside device to an associated railway safety assembly is to be set according to the measured velocity value when the rail vehicle drives into the switch-on section. Thereafter, a set correction time is checked to determine if the set correction time should remain effective according to at least one further influencing variable of the rail vehicle that determines the travel time. A railway safety system for carrying out the method is also provided.

Abstract: A pipe brace assembly includes a main clamp body that can be secured to a brace pipe. A cable, or other flexible tensioning member, can be wrapped around a braced pipe and secured to the main clamp body. The pipe brace assembly includes a method or mechanism for tensioning the cable or flexible tensioning member around the braced pipe. In some embodiments, the tensioning method or mechanism involves moving, such as rotating, the main clamp body to tension the cable or tensioning member. The clamping of the main clamp body and tensioning of the cable or tensioning member can occur simultaneously.

Abstract: A pipe mounting structure of a work machine that has a lightweighted structure and is able to stably mount many pipes thereon includes a structure for mounting pipes to a work machine such as a demolition machine. The structure includes at least a pair of protruding portions formed by upwardly protruding end portions of side plates of a front boom, a bridge member that is bridged between the pair of protruding portions, and connecting portions that connect the protruding portions and the end portions of the bridge member to each other, and the plurality of pipes are fixed to the bridge member.

Abstract: An adjustable weight supporting apparatus is provided with a horizontal member, an optional vertical member, an optional adapter, and legs. The weight supporting apparatus may be used to support the weight of an automobile or other object. The horizontal member may be placed on a lifting device, which may be lifted to contact an object. Legs and/or the vertical member may be added to the horizontal member to support the weight without a lifting force, which may be temporarily fixed in place with one or more pin. The horizontal member may include an elongated portion and a cuff. Various aspects of the apparatus may be adjusted to support a desired object at a desired height and/or footprint to provide sufficient access under the object. The leg may be a single curved piece or multiple pieces.

Abstract: A mounting device typically used for mounting line-of-site equipment, the mounting device including leg members that can fold into a trough like body of the mounting device, and further including a strap spool connected to an end portion of the mounting device. A strap on the strap spool can be unspooled and used to attach the mounting device to a surface.

Abstract: Mounting apparatuses, electronic device holders, and components of electronic device holders are shown and described herein. A mounting apparatus is removably connected to an object and the electronic device holder. The electronic device holder is configured to hold an electronic device and has one or more of an adaptor, a movable stand, and one or more portions of a backside thereof that are either clear or removed. The adaptor is removable from the electronic device holder for removal and replacement thereof with one or more additional, different adaptors.

Abstract: A mounting system for mounting a personal navigation device to a surface comprises a base assembly, a socket, and a mounting coupler. The base assembly includes a base, a mounting ball, and an arm connecting the base to the mounting ball. The socket may be integrated in the personal navigation device and includes spaced apart first and second magnets. The mounting coupler may attach to the mounting ball of the base assembly and removably couple with the socket of the personal navigation device. The mounting coupler may include a body and spaced apart first and second magnets. The body may include a forward wall configured to couple with the personal navigation device and a rear wall configured to couple with the base assembly. The magnets may be aligned with the magnets of the personal navigation device to ensure proper orientation of the personal navigation device on the mounting coupler.

Abstract: A support device is provided. The support device includes a support assembly with an elongated first body defining a cantilever mounting and a support surface.

Abstract: An adjustable mounting assembly has first and second mounting portions. The first mounting portion has an engagement arm with an adjustable end having first engagement teeth disposed about a first axis of rotation. The end portion has an adjustable second portion rotatable about the first axis of rotation, and having second engagement teeth that intermesh with the first engagement teeth to retain the second portion in an adjustable pan-position. The second portion has third engagement teeth disposed about a second axis of rotation angularly offset from the first axis of rotation. A second mounting portion is adjustably attached at an attachment portion to the first mounting portion, and the attachment portion has fourth engagement teeth disposed about the second axis of rotation that intermesh with the third engagement teeth to retain the second mounting portion is a selected tilt position.

Abstract: The first embodiment of the present invention presents a mobile device holder that is comprised of four components: a single finger holder, a single finger tensioner, a base platform; and an adhesive pad. The single finger holder and tensioner are permanently attached to form a first assembly, and the base platform and the adhesive pad are combined to form a second assembly. The adhesive pad has a cover that when removed may be used to attach the second assembly to a mobile handheld device. The first assembly is easily attached to and removed from the second assembly by a user. The first assembly may be rotated 360 degrees relative to the second assembly, and is held snugly in place by the single finger tensioner. Several additional embodiments are presented. One alternate embodiment replaces the single finger holder by a two-finger holder; another embodiment has an accessory that attaches to the handlebars of a stationary bicycle.

Abstract: An adjustable equipment mount assembly is configured to be adjustably secured within an overhead support module that is configured to be secured to a structure, such as a ceiling of an enclosed room. The overhead support module is configured to deliver air to the structure. The assembly may include an equipment mounting plate configured to connect to equipment, one or more first adjustable support members configured to allow the equipment mounting plate to be adjusted between different positions with respect to the overhead support module in a first direction, and one or more second adjustable support members configured to allow the equipment mounting plate to be adjusted between different positions with respect to the overhead support module in a second direction that differs from the first direction.

Abstract: A lifting and storage mechanism for storing a recumbent trike in a garage using the energy of a counterweight or motor is disclosed. The lifting and storage mechanism includes a pulley system that securely holds the trike in a horizontal balanced position while lifting and lowering the trike and while in a stored position. Counterweight reduces the pulling force required to manually lift the trike with pulley system; A motor can be used in place of counterweight to eliminate manual intervention.

Abstract: An adjustable stand holder includes a stand base including a base frame, an axle holder and a guide track arranged at the base frame at right angles, a cover member including a cover frame pivotally coupled to the axle holder and a smoothly curved stop flange raised from a front side of the cover frame for supporting a mobile electronic device on the cover frame, and a wheel receivable in the stand base and mountable between the base frame and cover frame to support the cover member in a tilted position relative to the stand base and movable along the guide track to adjust the tilting angle of the cover member relative to the stand base.

Abstract: A support for a variably positioning a platform which is adapted to hold a book or electronic display for convenient viewing, the support having a pair of swing arms pivotally connected together end to end and to an upright standard, with the platform connected to an outer end of one swing arm with a two orthogonal pivot connections to a platform mount and a pivot connection between the mount and platform. This creates five axes of independent pivoting movement of various components available to position the platform. A friction element for some of the pivot connections allows tightening of an adjustment screw to increase or decrease the friction to stabilize the platform in a selected position without tending to loosen the screw and the associated pivot connection.

Abstract: A vibration isolator with low elevation seismic restraint comprises a support member, at least two vibration isolating members, a top plate, a seismic snubber and a snubber limit plate. The vibration isolating members, are seated on the support member opposing end portions. The top plate has a middle portion and opposing end portions, wherein the top plate spans over the vibration isolating members, such that the vibration isolating members are between the support member and the top plate. The seismic snubber has a shaft element that is mounted to the top plate on one end. A snubbing limit plate is mounted to the support member such that it spans the U shaped support member middle portion, wherein the shaft member second end is between the snubbing limit plate, and the support member. The shaft member passes through the support member via a through-hole, and a first snubber element mounted to the shaft element second end, such that seismic movement is limited by the snubbing limit plate and the support plate.

Abstract: A cradle for mounting an engine in a vehicle has left and right side members, and a rear cross member and front cross member extending between the left and right side members. The cradle has left and right front body mounts. Left and right deflector devices are mounted respectively on the cradle adjacent the left and right body mounts and forwardly of the vehicle wheels. Each of the left and right deflector devices including an impact receiving member that projects outwardly and rearwardly from the cradle to receive an impact load offset outboard from the body mounts. Each impact receiving member has an upper and lower sheet metal shell providing a top wall welded to a top wall of the cradle and a bottom wall welded to the bottom wall of the cradle, and a front impact receiving wall extending vertically between the top wall and the bottom wall.

Abstract: An electronic device holder has a movable stand and is configured to be removably connected to one or more different mounting apparatuses that are connected to corresponding objects or directly to a plurality of different objects to support the electronic device holder and thus an electronic device held or supported by the electronic device holder. The movable stand has one or more elastic or stretchable strips that can be stretched or expanded to hold or support the electronic device holder and thus the electronic device.

Abstract: An aperture adjusting apparatus is provided. The aperture adjusting apparatus includes: a variable part of which an aperture size varies; an optical sensor configured to sense light incident to the variable device part and light output from the variable device part; an aperture calculator configured to calculate a size of an aperture formed in the variable part from light intensity sensed by the optical sensor; and a driving controller configured to control driving of the variable device part by receiving a calculation result fed back from the aperture calculator.

Abstract: An alignment system for a laser apparatus includes a guide laser device outputting a guide laser beam, an adjusting mechanism adjusting travel directions of the guide laser beam and a laser beam from the laser apparatus, a beam path combiner controlling travel directions of the laser beam and the guide laser beam to substantially coincide with each other, a first optical detection unit provided from the beam path combiner detecting the laser and guide laser beams, a first controller controlling the adjusting mechanism based on a first optical detection unit detection result, a beam steering unit downstream from the beam path combiner controlling travel directions of the laser and guide laser beams, a second optical detection unit downstream from the beam steering unit detecting the guide laser beam, and a second controller controlling the beam steering unit based on a second optical detection unit detection result.

Abstract: Apparatuses, systems, method, reagents, and kits for conducting assays as well as process for their preparation are described. They are particularly well suited for conducting automated analysis in a multi-well plate assay format.

Abstract: An electronic device may be provided with a touch screen display that is controlled based on information from a proximity sensor attached underneath a display layer. The proximity sensor may have a light source that emits infrared light and a light detector that detects reflected infrared light. When the electronic device is in the vicinity of a user's head, the proximity sensor may produce data indicative of the presence of the user's head. Variations in proximity sensor output due to smudges on the proximity sensor can be detected by providing the proximity sensor with an additional light source. The additional light source may be used to inject light into the display layer. The injected light may be guided within the display layer by total internal reflection. In the presence of smudge, the internally reflecting light may deviate from its normal propagation path.

Abstract: An optical detector is disclosed, having a plurality of detector cells, each detector cell comprising a light sensor, a charge accumulator, and a switch interposed between the light sensor and the charge accumulator; wherein the light sensor produces electrical current when illuminated by electromagnetic radiation, the charge accumulator accumulate electric charge when receiving the electrical current generated by the light sensor, and the switch is configured to controllably electrically isolate or connect the charge accumulator to light sensor, such that the charge accumulator accumulates charge only when electrically connected by the switch to the light sensor.

Abstract: A solid-state imaging apparatus includes a pixel unit which has a plurality of pixels disposed in a two-dimensional matrix shape, wherein each of the pixels that a photoelectrical conversion element which generates a photoelectrical conversion signal corresponding to an amount of incident light disposed on a first substrate, and which outputs a photoelectrical conversion signal generated by each of the pixels to each row as a pixel signal, and an analog-to-digital converter which is disposed on every one or more columns of the pixel unit and generates a digital signal by digitizing a phase state of a multi-phase clock including clock signals of a plurality of phases different from each other at predetermined fixed intervals according to the pixel signal. Each of first and second circuit configuration units whose circuit scales are determined according to the multi-phase clock is disposed on a different substrate of a first or second substrate.

Abstract: A device for color imaging including an optical sensor having light sensitive pixels with a metal film disposed over the light sensitive pixels. The metal film has a group of nano-holes arranged over the pixels according to a periodic lattice formation and is configured to pass light of a preselected first range of wavelengths. The group of nano-holes arranged over an adjoining group of pixels is configured to pass light having ranges of wavelengths different from the first range of wavelengths.

Abstract: A proximity sensor may include an array of Geiger mode avalanche photodiodes, each including an anode contact and a cathode contact. A common cathode contact may be coupled to the cathode contacts of the array to define a first connection lead at a back side of the array. A common anode collecting grid contact may be coupled to the anode contacts of the array to define a second connection lead of the array. Circuitry may be coupled with the first and second connection leads and configured to sense at least one of a dark current and a rate of current spikes generated in dark conditions, and generate an output signal representing, an estimated distance of an object from the array upon the sensing.

Abstract: A deep SPAD structure uses the substrate as the anode terminal of its multiplication p-n junction. A bias voltage for the SPAD (in excess of the SPAD's breakdown voltage) is coupled to the SPAD's cathode terminal. The bias voltage is generated by a charge pump circuit which is also integrated on the substrate. The charge pump circuit is configured to isolate the bias voltage on the cathode terminal. A triple well CMOS process is used to isolate the transistors of the charge pump circuit from the substrate.

Abstract: A wavelength tunable interference filter includes an electrostatic actuator that changes the dimension of a gap between a fixed reflection film and a movable reflection film, a fixed drawn electrode and a movable drawn electrode that are connected to the electrostatic actuator, and a third substrate having a top surface portion and a sidewall portion. An end surface of the sidewall portion is bonded to a first substrate so that a space surrounded by the top surface portion, the sidewall portion, and the first substrate is hermetically sealed. A second substrate and the electrostatic actuator are disposed in the space, and the fixed drawn electrode and the movable drawn electrode are disposed on the first substrate and extend both inside and outside the space.

Abstract: A detector system having a single emitter body. The emitter body has a plurality of light emitting diodes (LEDs) for emitting a plurality of wavelengths. Each LED adapted to emit a different wavelength of light. A broadband filter is adapted to receive the plurality of wavelengths. A detector arrangement adapted to receive the plurality of wavelengths filtered by the broadband filter. A controller adapted to control the plurality of LEDs and detector arrangement.

Abstract: An apparatus and a system for measuring flicker of a display panel are disclosed. The apparatus comprises a light guide tube, a measuring probe for flicker measurement, and an optical device for diverging fight. The light guide tube comprises an opening at a first end and an opening at a second end. The trumpet-shaped light guide tube gradually enlarges from the opening at the second end to the opening at the first end. The opening at the first end is used fir receiving light emitting from the periphery regions and the center region of the display. Light entering into the light guide tube through the opening at the first end emerges from the opening at the second end and is transmitted to the measuring probe through the optical device having a diverging effect. The more overall flicker information is acquired to improve the accuracy of measurement.

Abstract: An optical encoder is disclosed. Specifically, a three-channel encoder is disclosed which utilizes a single track for all three channels. An index channel is provided on the same optical track as the first and second channels which are used to determine incremental angular position. Thus, a more compact and simple three-channel encoder is provided.

Abstract: A disclosed formation monitoring system includes a casing that defines an annular space within a borehole. An array of electromagnetic field sensors is positioned in the annular space and configured to communicate with the surface via a fiberoptic cable. A computer coupled to the fiberoptic cable receives said measurements and responsively derives the location of any fluid fronts in the vicinity such as a an approaching flood front to enable corrective action before breakthrough. A disclosed formation monitoring method includes: injecting a first fluid into a reservoir formation; producing a second fluid from the reservoir formation via a casing in a borehole; collecting electromagnetic field measurements with an array of fiberoptic sensors in an annular space between said casing and said borehole, said array communicating measurements to a surface interface via one or more fiberoptic cables; and operating on said measurements to locate a front between the first and second fluids.

Abstract: The present invention provides a timing device, especially a timing device for use in mass spectrometers, for example TOF mass spectrometers, for processing trigger signal data containing a trigger signal indicating the occurrence of a trigger event, the timing device having: a trigger signal deserialiser configured to receive trigger signal data containing a trigger signal indicating the occurrence of a trigger event as serial data and to output the trigger signal data as parallel data, and wherein suitably the timing device has a processing means configured to process trigger signal data outputted by the trigger signal deserialiser as parallel data.

Abstract: A mass analyser comprises: an electrical field generator, providing a time-varying electric field for injection of ions to be analysed, excitation of ions to be analysed or both; first and second detection electrodes, each of which receives a respective voltage pickup due to the time-varying electric field and provides a respective detection signal based on a respective image current at the detection electrode; and a differential amplifier, providing an output based on the difference between the detection signal for the first detection electrode and the detection signal for the second detection electrode. It may also be provided that the electrical field generator comprises at least one field generating electrode without a spatially symmetrical counterpart and the capacitance between each field generating electrode and the first detection electrode is substantially the same as the capacitance between that field generating electrode and the second detection electrode.