Abstract: A X-ray exam system includes an x-ray source, a detector positioned to receive x-rays transmitted for the x-ray source, a patient table positioned so that the x-ray source emits x-rays towards a patient thereon, a video monitor for displaying images while performing an exam, and a voice activated control system coupled to the x-ray source, the detector, and the video monitor. The voice activated control system configured to control playback imaging sequencing based on a voice command to facilitate analysis of a plurality of acquired images. The control system includes an audio microphone configured to be positioned for receiving audio input from an operator, and an audio signal processor coupled to the microphone for processing amplified audio signals from the amplifier. The processing includes at least one of word and phrase recognition.

Abstract: A method and apparatus for an x-ray tube having an emitter and a differentially biased emitter-cup cathode configured to provide an electron beam of substantially greater perveance and beam compression ratio than otherwise obtainable with conventional cathode designs is disclosed. The method and apparatus include a cathode assembly opposing an anode and spaced apart therefrom. The cathode is maintained during operation of the x-ray tube at a negative potential with respect to the anode. The cathode assembly includes an emitter for emitting an electron beam to a focal spot on the anode during operation of the x-ray tube and a cathode front member having an aperture defined by the cathode front member on a first side of the emitter. A backing is disposed on a second side of the emitter and is operably connected to the cathode front member via a backing insulator. The cathode further includes a means for applying a differential bias in the cathode assembly to variably change the focal spot size.

Abstract: A personnel x-ray inspection system includes an electron source that provides a pencil beam of electrons. An electromagnet assembly receives the pencil beam of electrons and directs the beam of electrons along a line to form a scanning redirected beam under the control of a scan command signal. The scanning redirected beam strikes a target and generates a cone of x-rays that moves along a target line as a result of the scanning redirected beam. A collimator receives the scanning cone of x-rays and generates a collimated traveling pencil beam, which is directed to a person under inspection. A moving platform translates the person under inspection through the collimated traveling pencil beam. A backscatter detector detects backscattered x-rays, and provides a backscattered detected signal indicative thereof. A system controller provides the scan command signal, and also receives and processes the backscattered detected signal.

Abstract: In order to provide in-region, interLATA service, a bell operating company (BOC) must provide telecommunications service to competitive local exchange carriers (CLEC) in a non-discriminatory manner. To demonstrate that the BOC service to the CLEC is non-discriminatory, the BOC provides a series of performance measures to regulatory agencies and to the CLEC. A system and method is described for ensuring the quality of those performance measurements. The system and method provide for identifying sub-processes within a performance measurement process (PMP), identifying critical audit points within each sub-process, and implementing control measures corresponding to each critical audit point. The system and method help to eliminate the need for time-consuming and expensive third-party audits of the PMP.

Abstract: In order to check the functionality of a switching center (VST) which is to be tested in a telecommunications network in which user information on the subscriber connections is interchanged via intermediate interfaces (NK1, NK2) with a respectively connected switching center, and signaling messages for controlling the subscriber connections and for administration of the intermediate interfaces (NK1, NK2) are interchanged via signaling interfaces (SSS), original signaling messages which have been transmitted from the switching center (VST) and in which the switching center (VST) is stated as the source point are received, the original signaling messages are each converted in accordance with a predetermined rule into signaling messages in which the switching center (VST) is stated as the destination point, and the signaling messages which have been converted in this way are sent to the switching center (VST).

Abstract: A voice message delivery method and system for delivering voice messages from a Sender to a Receiver, where neither the Sender nor the Receiver are required to be Subscribers to the system. The invention allows voice messages to be delivered to non-Subscribers and, if they are not how, to be recorded into the existing answering machine or voicemail system of the Recipient. Advertisements played during either the process of sending or receiving a message provide revenue for a company providing the service of the present invention without requiring users to become Subscribers.

Abstract: A sound source management system for a telephone switching network is disclosed in which, in response to a sound source capturing request from a subscriber through a call processing unit, a sound source management unit drives an idle sound source detection unit to refer to a sound source management data storing unit, so as to detect an idle sound source connected to the own switching unit or connected to another switching units, and when an idle sound source is detected, the detected sound source is captured so that a sound from the captured sound source is sent to the subscriber, whereby a momentary resource shortage in each switching unit can be avoided economically and without affecting the traffic of the overall network.

Abstract: A barge-in detector for use in connection with a speech recognition system forms a prompt replica for use in detecting the presence or absence of user input to the system. The replica is indicative of the prompt energy applied to an input of the system. The detector detects the application of user input to the system, even if concurrent with a prompt, and enables the system to quickly respond to the user input.

Abstract: Whether a call is placed after waiting for confirmation operation or without waiting for confirmation operation upon completion of speech recognition is selected. Data is initialized in the standby state, and upon instruction of speech recognition, speech recognition is done. The speech recognition result is displayed, and when a speech recognition key is operated without any confirmation operation, speech recognition is redone without setting the standby state.

Abstract: The present invention relates to a system for automatically identifying enunciation of telephone numbers and email addresses in voice mail messages for presentation to a user via either voice or text, without the user being required to replay the message. Furthermore, according to the invention the extracted telephone number or email addresses may be forwarded to an application for further processing (e.g. to dial the extracted number, add the email address and/or telephone number to a contacts database, etc.) The user may specify text strings to be searched (other than telephone numbers and email addresses). Thus, a user can specify certain words such as “extension”, “email”, etc., in order to qualify the extracted number or email address information, or words such as “urgently” or “immediately” to identify important voice mail messages.

Abstract: An on-demand caller ID service is disclosed. A customer dials an access code to retrieve calls made to his telephone number. An automated voicemail response system would repeat the telephone numbers and/or names associated with those telephone numbers that called over a predetermined time period, such as the last 24 hours. The customer is billed a per usage charge for each time he accesses the service. The customer may also subscribe to the service. Customers that are not subscribers of caller ID may utilize this service if they are seeking to track down an incoming call that may have been missed during the day. Also, customers who are away from their telephone line may remotely check who has called them by accessing the service.

Abstract: A system and method for playing back data segments stored in one or more locations and managed by one or more playback servers. In a preferred embodiment the system and method receive data describing data segments to be played back; transmit notifications to the playback servers to prepare for playback; and transmit playback requests to the playback servers. The system and method are also capable of playing back the segments in a specified order and such that gaps between the segments are minimized. Additionally, a graphical display can be provided to display the status of the segments being played back.

Abstract: A system and method for monitoring a telephone switching environment. In a preferred embodiment the system and method construct a call record for each telephone call; receive data regarding telephony events; match a received telephony event with a call record; update the matching call record based on the received telephony event data; and combine the updated call record with data indicating the location of recorded audio data for the segment of the call, to generate a master call record representing the lifetime of the telephone call. Additionally, the system and method are capable of assembling and playing back segments of telephone calls using the recorder locations described in the master call record for each telephone call, and of using the master call record to display a graphical representation of the telephone call.

Abstract: A quick startup procedure for a modem system utilizes known characteristics of a previously established communication channel to reduce the initialization period associated with subsequent connections over the same channel. In response to the establishment of a call, the modem devices determine whether the quick connect protocol is supported. If so, then the called modem transmits a modified answer tone to the calling modem. The calling modem analyzes the signal received in response to the modified answer tone to determine whether characteristics of the current channel are similar to stored characteristics associated with a previous connection over the same channel. If a channel “match” is found, then the modem devices carry out a quick initialization routine that eliminates, abbreviates, or modifies a number of procedures or protocols that are carried out in conventional modem startup processes.

Abstract: A method and apparatus for providing prepaid local telephone services is provided. The method includes determining if a subscriber is making a qualified local telephone call, checking to see if a maximum number of calls have been made by the subscriber and decrementing a call counter if a telephone call in connected. The system includes a switch for receiving telephone calls and identifying subscribers and qualified telephone calls. In addition, the system includes a telephone network element in communication with the switch, the telephone network element having logic for identifying local telephone calls, a notification timer configured to remove the telephone network element from a telephone call after a predetermined period of time, and a call counter for monitoring a number of local calls permitted to a subscriber.

Abstract: A system and method for providing call information query stores modified call information associated with a telephone number within the local databases of a service provider's local network. The modified call information enables a service provider to unilaterally alter how calls are routed and rated. The service switching points (SSPs) located within a same local network are equipped with modified intelligent network or advanced intelligent network software that enables the local SSPs to receive remote call information resulting from a remote query performed by a remote SSP. The local SSPs analyze the remote call information and generate queries to their local databases to obtain modified call information. New services requiring modified call information can then be implemented based upon the modified call information received as a result of the queries.

Abstract: Transaction Capabilities Application Part (TCAP) information from an Signaling System 7 (SS7) network (11) is provided, in response to an original SIP-compatible request by an SIP entity (17) in an SIP network (10), to the SIP network where the TCAP information is then used to facilitate call setup and routing of the call. In one embodiment, the SIP network locally stores the TCAP information upon receipt (at least temporarily) such that the TCAP information is available for subsequent local use without requiring a correspond inquiry to the SS7 network.

Abstract: A computer telephony interface includes both first party and third party call components. A telephony server is arranged to control one or more of plural network nodes and has a control interface having a call model and call components for (a) at least one first party call and (b) at least one third party call. First and third party call components are linked to a single call model.

Abstract: A method for enabling user interaction between a user terminal, at least one service switching point and at least one service control point in an intelligent network. An operator position comprising a computer terminal is coupled to the service control point and a telephone terminal is coupled to the service switching point. If the service control point requires input data for executing a service, it sends a request to the operator position, where the operator is prompted to request the necessary information from the user that invoked the service. The service switching point establishes a connection between the user's terminal and the operator position telephone terminal. The operator handles the user interaction between the service control point and the user terminal via the operator computer terminal and the operator telephone terminal. Once the necessary information has been obtained, the operator sends the user information to the service control point.

Abstract: A first call processing system advantageously uses a constant bit rate connection and a variable bit rate connection to utilize the bandwidth for a data call. The first call processing system receives signaling for the data call. The first call processing system then processes the signaling to generate a first instruction to set up a constant bit rate connection for the data call between the first call processing system and a second call processing system. The first call processing system processes the signaling to generate a second instruction to set up a variable bit rate connection between the first call processing system and the second call processing system. Any bandwidth that the data call does not need and use can be utilized for other calls. Thus, the performance of other calls is improved.

Abstract: A method of routing signalling information at a signalling transfer point of a telecommunication network. A Global Title Routing Case (GTRC) table is provided for mapping Global Titles to GTRCs, where each GTRC is allocated a primary and secondary destination signalling point. At least one peak time period is predefined, and said primary and secondary destination signalling points are swapped for a fraction of said GTRCs during said peak period to allow for load sharing during this period. For a signalling transfer request received at the signalling transfer point, the Global Title associated with the request is mapped to a GTRC using the GTRC table, and the destination signalling point is determined in dependence upon the primary and secondary destination signalling points allocated to the mapped GTRC and signalling point availability, and, in the case of said fraction of GTRCs, the time at which the request is received.

Abstract: A Call Management System provides for management of calls directly by system users at their workstation computers via a digital data network such as a digital networks not controlled via the user's telephone instruments as in prior systems. A call management computer intercepts incoming calls and controls the handling of such calls according to instructions received from the users' workstations, which are accessed via the digital data network. Trunk circuits are monitored and controlled using digital signal processors to proactively identify the called party, the calling party and the call type (voice, Fax, data) and control and to monitor all calls. Each different type of call is managed differently and automatically through direct user workstation controls and/or user-generated rules to provide special treatment for designated callers. Multiple calls to user at the same time may be handled with no busy signals to callers. Only one number is needed for a user to receive voice Fax and data calls.

Abstract: A communication processing system includes a network having a number of agent terminals associated therewith and one or more processing elements enabled to support a distributed system deployment protocol. The distributed system deployment protocol is utilized in the system to configure one or more of the agent terminals for communication with customer terminals via the processing element(s) in order to provide designated services. The agent and customer terminals are also preferably enabled in accordance with the protocol such that configuration of these terminals to support and to utilize call center services is implementable without requiring the use of disk-based memory at the terminals.

Abstract: A telephone having a hands-free mode of operation. The telephone includes a pair of microphones spaced apart from each other. Each microphone receives sound in hands-free mode of operation and provides audio signals representative of received sounds. The audio signals from each microphone may be converted to digital audio signals. The digital audio signals are presented to a fixed delay path and a variable delay path. Audio signals from both paths are combined and filtered in an adjustable filter to remove noise based upon a prior determination of the noise source location and the voice spectrum derived from the digital audio signals.

Abstract: In a speakerphone system, the signal that is directed to a loudspeaker is filtered by a dynamically controllable highpass filter. The filter characteristics are adjusted on the basis of the power of the signal and the degree of recent microphone activity. The filtered signal is a far-talker signal, while the microphone activity is represented as a near-talker signal that includes an echo component as a consequence of loudspeaker-to-microphone coupling. The degree of microphone activity is determined by a subband analyzer. A noise floor estimator may be used to determine the degree to which the near-talker signal is comprised of background noise, so that the noise can be eliminated in the process of controlling the highpass filter.

Abstract: A telephone line connection and disconnection circuit has a diode bridge coupled to the telephone line which converts different voltages of the telephone line into a voltage referenced to ground. A switching circuit is coupled to the diode bridge which opens and closes a conductive pathway for connecting and disconnecting a telephony product from the telephone line. A resistive element is coupled to the diode bridge and the switching circuit which allows for the conductive pathway to be normally closed. An optical isolator is coupled to the switching circuit and the resistive element for sending a control signal to the circuit when required.

Abstract: A two-step training method for the estimation filter in the echo cancellation (EC) path of the analog front-end (AFE) circuit for a modem, such as an asymmetric digital subscriber line (ADSL) modem. During the first step, the transmit (TX) path is turned off and a digital TX signal (e.g., a pseudo white gaussian noise signal) is applied to the EC path essentially bypassing the EC estimation filter. During the second step, the EC path is turned off and a digital TX signal (e.g., the same pseudo white gaussian noise signal) is applied to the TX path. Coefficients for the EC estimation filter are then generated based on the digital RX signals recorded during the two training steps. In particular, the recorded digital RX signals are transformed to the frequency domain, where one is divided into the other. The resulting digital signal is then transformed back to the time domain, where it is used to generate the coefficients for the EC estimation filter.

Abstract: A safety helmet structure includes a safety helmet formed with a base portion which is located at a position adjacent to a user's one ear. The base portion is provided with an insertion groove which is provided with a threaded seat. A seat is mounted on the base portion and provided with an insertion flange that may be inserted into the insertion groove of the base portion. The seat has a receiver, and a speaker. A signal connecting cord is extended from the seat, and connected to a mobile telephone. The seat is provided with a through hole for passage of a threaded rod. The threaded rod is provided with a thread that mates with the thread of the threaded seat. A spring is mounted between the base portion and the seat for adjusting the protruding position of the seat.

Abstract: A rear cover of a radio handset having a scooped recess for improving the ergonomics of the phone for single-handed operation.

Abstract: In order to be able to convert a fully functional telephone, in particular a mobile telephone, into a “child's telephone” without requiring a large degree of expenditure, it is provided that, if appropriate in addition to further keys, just one of more keys for dialing a telephone number are accessible on the telephone, which further keys cause a stored telephone number to be dialed when they are activated.

Abstract: An encryption/decryption method applicable to product-sum cryptosystem. This method enables highspeed decryption. A ciphertext C=m0B0+m1B1+ . . . +mK−1BK−1 is produced from a scalar product of a plaintext vector m=(m0, m1, . . . , mK−1) and a base vector B=(B0, B1, . . . , BK−1).

Abstract: A bitstream generator including a plurality of linear feed shift registers (LFSRs) operative to generate a bit stream and including: at least a first LFSR operative, when assigned as a generator during a first time period including at least one clock cycle, to provide an output bit in each clock cycle within the first time period, and at least a second LFSR operative, when assigned as an assignor during the first time period, to provide in each clock cycle an output bit for determining assignments of at least some of the plurality of LFSRs for a second time period following the first time period, the assignments including assignment as a generator, and assignment as an assignor, and a first combiner operative to combine output bits from all of the at least a first LFSR being assigned as generators thereby to produce during each clock cycle a single output bit which is provided to the bit stream. Related apparatus and methods are also provided.

Abstract: A system and method of receiving and decrypting encrypted data using a key based upon an initial key used for encryption that is received at a receiving unit whereby a key is generated from the initial encryption key for decryption. The key used to encrypt the data at a transmitting unit periodically changes and is indicated to the receiving unit by using an odd or even flag that is attached to the encrypted data. By observing the flag and whether the flag polarity is odd or even, a new key corresponding to the key used for encryption is generated to provide uninterrupted reception of asynchronously transmitted data.

Abstract: N correlated signals are processed by N pre-filters whose transfer characteristics have different zero points, then the processed signals are input into an N-input M-output linear FIR system, and its transfer characteristics are estimated from its response outputs and the processed signals from the pre-filters.

Abstract: Apparatus and methods for enabling and disabling an amplifier is described. Amplifiers can be enabled and disabled for the sake of power and energy savings and reduction of dissipated heat. The circuit is based on a gain stage and threshold circuitry. A signal associated with an amplifier is introduced into the gain stage. The gain stage amplifies the signal level and provides the amplified signal level to threshold circuitry. The threshold circuitry references the amplified signal level and determines signal states. The control circuitry interprets these signal states to determine when to enable or disable an amplifier. The output of the threshold circuitry can be used to adjust the amplified signal level to oppose drift in the gain stage.

Abstract: A device (MS) having an electrical display (DSPL) is equipped with a transparent electrostatic diaphragm (ACT) vibrateably attached in front of the display. The display has been made electrically conductive and used as a stator of thus formed electrostatic speaker (TD1). A fluctuating DC-voltage is conducted to the diaphragm and display in order to resonate the diaphragm and produce sound respective to the fluctuation. The transparency of the diaphragm allows a user to see the display through the diaphragm. Alternatively, the similar arrangement can be used to implement a transparent electrostatic microphone on the display.

Abstract: A method and apparatus is provided for a hearing aid capable of determining its accumulated utilization time and making use of this information to control one or more of its functions. The control of the hearing aid's function may be obtained through alteration of parameters of a signal processing algorithm of the hearing aid or by execution of a particular transducer adjustment subroutine or algorithm. The accumulated utilization time may furthermore be utilized to provide a function that makes the hearing aid inoperative when a value of the accumulated utilization time matches some predetermined criteria, such as a predetermined limit value. Such a function is highly desirable if the hearing aid is sold in connection with a subscription arrangement between a dispenser and a hearing aid user where the user pays for his or her hearing aid through payment of regular renewal fees.

Abstract: A portable device includes a speaker with an active vent fed by a front of a speaker diaphragm and a larger passive vent fed by a rear of the speaker diaphragm. The outputs of the active and passive vents are acoustically coupled to respective active and passive ports, coupled together outside of the housing within an ear placement region for a user of the portable electronic device to obtain a more uniform frequency response from the speaker configuration over a larger region of a user's ear placement possibilities than would be available with the active vent alone. This is accomplished by a close acoustic coupling of the ports in combination with diverse porting of active and passive acoustic signals. The passive path also serves to relieve pressure near a user's ear to improve signal quality.

Abstract: An earphone comprises a main body and an ear hanger. The main body is to be placed at an entrance of an external auditory meatus of an ear of a user. The main body includes a loudspeaker received therein. The ear hanger is connected to the main body. The ear hanger is adapted to be mounted on the ear. The ear hanger has a curved shape. The ear hanger comprises a core and a sheathing member for surrounding at least part of the core so as to provide a dual structure. The core is formed of hard material and the sheathing member is formed of elastic material.

Abstract: An electro-acoustic converter, comprising a barrel shaped diaphragm (2) formed about a longitudinal axis (3) and comprising first and second annular opposed ends (4, 5), and a first electrically driven vibration generator (6-11) for inducing a vibrational movement in the first annular end in the direction of the longitudinal axis.

Abstract: To provide an electronic watermark method and system for which the detection reliability of embedded information does not depend on the strength of signals that are measured in frames. To achieve the above object, information is prepared for embedding as a bit stream, the sign of the bit stream being changed in accordance with a sign inversion cycle, and the bit stream being embedded in a frame. As for detection of information, values obtained through observation of frames are accumulated, and the accumulated values are compared with threshold values that are varied in accordance with the accumulated values obtained by observation. The comparison results are then employed to detect the embedded information.

Abstract: In a communication system, a transmitting device transmits an image datum to which a specified datum is inserted as an electronic watermark by watermark insertion technique. The image datum represents an image. The specified datum represents a specified process for a receiving apparatus for receiving the image datum. In the receiving apparatus, a processing arrangement is responsive to the image datum and processes the specified datum to execute the specified process. A producing arrangement is responsive to the image data and produce the image.

Abstract: A spray data acquisition system includes a pumping device responsive to an applied force to generate an aerosol spray plume along a spray axis. The system further includes a spray pump actuator that is capable of controlling the pumping force and the duration of the aerosol spray plume produced by the pumping device. The system also includes an illumination device that illuminates the aerosol spray plume along at least one first geometric plane that intersects the aerosol spray plume. The system further includes an imaging device that acquires data representative of an interaction between the illumination and the aerosol spray plume along at least one geometric plane.

Abstract: A method of synchronizing a watermark decoder with a watermark encoder uses a spatio-temporal (3D) synchronization pattern added to a data pattern to produce a watermark pattern for embedment into a signal. The spatio-temporal synchronization pattern is formed by multiplying a spatial (2D) synchronization pattern with a pseudo-noise sequence for a block of signal frames having a duration of N frames. Quadrature carrier modulation may be used to increase detectability of the watermark pattern at the watermark decoder. The watermarked signal is correlated with the spatial synchronization pattern to recover a temporal synchronization signal that is used to determine a temporal offset between the watermark encoder and watermark decoder. The temporal offset is then used to synchronize the watermark decoder with the watermark encoder.

Abstract: A system and corresponding method for head tracking and color video acquisition via near infrared luminance keying is disclosed. The head of the local user is tracked in real time by uniformly illuminating a rear projection screen that surrounds a display cube with light having a wavelength in the near-infrared spectrum. A near-infrared image of the head of the local user is acquired by a near-infrared camera equipped with filters that discern the difference between the illuminated rear projection screen and any foreground illumination. A color image of the head of a local user and the projection of a remote location are acquired by a color camera, placed in close proximity to the near-infrared camera. A bounding box is then placed around the head of the local user in the near-infrared image. This bounding box is then translated to the view space of the color camera. This translated image is then used to crop the color image. The cropped color image is then transmitted to the remote location.

Abstract: An optical axis direction, a distance measurement accuracy and so on are efficiently performed for quality assurance of a vehicle-mounted camera in cooperation of an image processing unit and a vehicle-mounted navigation control unit. In a vehicle monitoring system for imaging view ahead of the vehicle with the camera (2a, 2b) installed in the vehicle body and for recognizing a running condition with the image processing unit (20), the image processing unit measures an optical axis direction and a distance measurement accuracy to determine whether the camera quality is appropriate or not for quality assurance of the vehicle-mounted camera. The determined result is displayed on a monitor (52) of the vehicle mounted navigation control unit (5) to recommend adjustment of the camera.

Abstract: An image positional relation apparatus is provided, in which coordinate data of a real targed photographed by a CCD camera and coordinate data of a virtual target logically calculated from the predetermined position of the real target are transmitted to a superimpose circuit, and the real target and the virtual target are superimposed to be displayed on a monitor screen. A user operates a controller so that the real target coincides with the virtual target. An amount of such operation is transmitted to the superimpose circuit as a correction amount, and the positional relation between the real target and the virtual target, i.e., the positional relation between the real image and the virtual image can be properly corrected.

Abstract: Apparatus and a method are disclosed for reading and authenticating documents. These documents include passports, driver's licenses, identity documents and documents of value, and they are read to obtain and verify information recorded thereon, and to test for and detect security features thereon to determine if such documents are genuine, counterfeit or have been altered. A first image is taken of a document under evaluation and, from the image, the size of the document is determined, and that defines the document as being part of a smaller class of documents having the same size. Reference documents for all documents types are segmented and a correlation number is determined for each segment. A correlation number is determined for each segment of the first document having fixed information, and these correlation numbers are compared with correlation numbers of corresponding segments of the reference documents that have the same size as the first document.

Abstract: An iris authentication apparatus performs authentication based on data generated from a human iris in which camera section and a signal processing section detect an iris state in the form of data. By using a database section, an iris data processing section detects whether the iris state is in a living body state. When the iris data processing section has detected that the iris state is in a living body state, it is judged that the detected data is effective. In this manner, the iris authentication apparatus can reliably prevent a third person from being authenticated by pretending to be a registered person by forging an iris pattern that is a non-living-body iris.

Abstract: This invention relates to an apparatus for measuring structures in a fingerprint or the like, comprising at least one sensor array adapted to be positioned close to, or in contact with, the surface of the fingerprint, the sensor array being adapted to measure chosen characteristics of the surface, e.g. by measuring capacitance or resistivity, at a plurality of positions. At least one sensor array comprises at least one line of sensors, adapted to measure said characteristics at chosen intervals of time, the surface having a relative movement in relation to the sensor array with a direction essentially perpendicular to the at least one line of sensors, and at least one of the outer ends of at least one sensor array protrudes towards the surface to be measured, providing an essentially U-shaped cross section in a plane perpendicular to the direction of said movement.