Abstract: The protection circuit comprises a clamping circuit with a switching element for reducing a supply voltage in case of an over voltage condition, and a holding circuit for providing a holding current for the clamping circuit. The clamping circuit comprises a threshold circuit, which provides a switching voltage for a switching element when the supply voltage reaches an upper voltage limit. The switching element is connected to a charge capacitor, which provides the switching-on voltage for the switching transistor, and by reducing this supply voltage, the switching of the switching transistor is disabled. The holding circuit comprises in particular a capacitor, which is coupled via a resistor to the clamping circuit for providing an additional current in case of an over voltage condition.

Abstract: The present invention relates to a method for identifying a data area D,E or D,G, reserved in accordance with a first specification, as useful data area G in accordance with a second specification.

Abstract: A method for power level control in a Plasma Display Panel with which the Peak White Enhancement Factor can be increased. The method includes the provision of a set of power level modes for the sub-field coding. To each power level mode a characteristic sub-field organization belongs. The sub-field organization is variable in respect to one or more of the following characteristics: the number of sub-fields the sub-field type the sub-field positioning the sub-field weight the sub-field pre-scaling a factor for the sub-field weights which is used to vary the amount of small pulses generated during each sub-field. The method includes the steps of determining a value which is characteristic for the power level of a video picture and selecting a corresponding power level mode for sub-field coding.

Abstract: A method for convergence correction in a projection television display having a monochromatic tube for each of the three primary colors red, green and blue, whose images can be projected on a screen. Each tube has an associated deflection correction device which comprises a convergence circuit. Convergence correction values are determined by measurement using sensors with screen edge locations which cannot be seen. Convergence correction values are calculated for the entire screen by interpolation between these values.

Abstract: A method of operating a photo sensor in a projection display device comprises the steps of, illuminating the sensor with a projected image. Detecting a signal from the sensor responsive to the illumination by the projected image. Changing a threshold value of the detector until the signal detection ceases. Storing a value representative of the threshold value which terminated detection of the signal from the sensor.

Abstract: An image display is operable with video signals having a plurality of scanning frequencies and comprises a cathode ray tube for the display of ones of the video signals. A deflection coil is mounted on the cathode ray tube and a horizontal deflection amplifier is coupled to the deflection coil and generates a deflection current therein. A plurality of retrace capacitors are controllably coupled to the horizontal deflection amplifier in response to a selected scanning frequency to maintain a substantially constant active picture display area with the ones of the video signals having the plurality of scanning frequencies.

Abstract: A wireless telephone system comprises one or more wireless handsets and a base unit. Each handset has a handset transceiver and a rechargeable handset battery for powering the handset. The base unit has a base transceiver for communicating over an RF channel with each handset via its handset transceiver; a recharge cradle for physically docking a docked handset battery comprising one of a detached handset battery and a handset; and a recharge unit for recharging the docked handset battery. The base unit is coupled to an AC power supply and utilizes the docked handset battery as a backup power supply if AC power from the AC power supply is lost or irregular to prevent communication between the base unit and the handsets from being disrupted.

Abstract: DVDs have currently the highest storage density among the optical discs of practical use. Due to the high storage density the reproduced signal is deteriorated by noise caused by inter-symbol interference, crosstalk, focus error, or mastering errors. A conventional threshold bit detector generates a high bit error rate in case of low SNR. For accurate reproduction of digital data from a DVD under low SNR conditions, a specific Viterbi detector is used which performs maximum likelihood sequence estimation.

Abstract: A power supply for a video display tube includes a deflection transformer with a primary winding powered with a scan voltage which has a first value when displaying signal according to a first video standard and a second voltage when displaying video according to a second standard. A secondary winding of the transformer produces filament voltage for the display tube. A variable coupler couples the filament voltage to the filament of the picture tube in an amount established by a control signal. A memory produces a first control signal in response to the first scan voltage and a second control signal in response to the second scan voltage. The first and second control signals are selected so that the voltage coupled from the transformer to the filament is the same at both scan voltages.

Abstract: A wireless telephone system comprises a base transceiver having a base receiver and a plurality of wireless handsets. Each handset comprises a handset transceiver for establishing a time-division multiple access (TDMA) link over a shared channel with the base unit via the base transceiver, in which each handset communicates during an exclusive time slot of a TDMA scheme that allocates time slots to handsets. The base receiver is characterized by a plurality of demodulation parameters and is for synchronizing with each handsets. The base receiver stores a set of demodulation parameters for each handset and switches to the set of demodulation parameters for a particular handset when the base unit is to synchronize with the particular handset.

Abstract: A method for rewriting onto a disk medium capable of being rewritten a limited number of times, comprises the steps of: encoding as data blocks all programs to be recorded; writing any encoded program onto a track on the disk medium as a given sequence of encoded data blocks; and, precessing along the track when overwriting the given sequence of encoded data blocks with a subsequent sequence of encoded data blocks. An apparatus comprises a controller for enabling any encoded program to be written onto a track on a disk medium as a given sequence of encoded data blocks. When overwriting the given sequence with a subsequent sequence of encoded data blocks, the controller precesses the rewriting along the track.

Abstract: A projection television receiver having red, green and blue image projectors for respective images of different colors and a high gain projection screen formed by at least one hologram disposed on a substrate superimposed on at least one light transmissive panel. The high gain holographic screen provides increased horizontal viewing performance over lenticular (e.g., fresnel) screens without reliance on screens having wide horizontal half viewing angles.

Abstract: An inventive method for preventing focus flutter display in a TV receiver or monitor includes the steps of amplifying a received signal for driving cathode elements of a cathode ray tube, and delaying initial full amplification of the signal during the amplifying step for a duration sufficient to prevent focus flutter display on the tube. A corresponding inventive kine driver circuit that prevents display of focus flutter includes an amplifier for amplifying and coupling received video signals to cathode elements of a picture tube, and a control circuit for delaying full amplification of the video signals to be fed to the cathode elements for a duration sufficient to prevent focus flutter display on the tube.

Abstract: In order to avoid, during trick mode, jittering of a second image superimposed on a first image, the arrangement is able to provide a signal including a vertical synchronisation signal and representative of a first image to a screen. The arrangement also generates a second image to be synchronised with the first image. The arrangement is able to perform a pseudo-vertical synchronisation signal. A selection is made to use whether the vertical synchronisation signal or the pseudo vertical synchronisation signal depending on the mode in which the arrangement is functionning.

Abstract: A method and apparatus for responding to an incoming call on one of a plurality of external telephone lines when a conference call is in progress on that external telephone line includes the following. First, caller identification information is received relating to the incoming call. Then the plurality of handsets involved in the conference call are notified that an incoming call has been received. Should it be desired to answer that incoming telephone call via a callback, a pre-recorded message is transmitted to the caller of the incoming call requesting the caller hang up and the incoming telephone call is terminated. The caller of the incoming call is then called back on a unused external telephone line using the previously received caller identification information relating to that incoming call. Finally, one of the plurality of handsets involved in the conference call is connected to the caller of the incoming call.

Abstract: Video recording according to the DVD-VR Specification allows to record only one sub-picture stream. Therefore, a new technique is provided in order to be able to record at least two different sub-title streams in such a way that the sub-pictures of the different streams may be displayed optionally. A first sub-picture stream is directly copied to the DVD-VR disc, whereas a second or third sub-picture stream is transcoded to Teletext format so that the data can be included into the video stream to be recorded on the DVD-VR disc. Thus, several sub-titles are available during replaying a DVD-VR disc.

Abstract: A method for the reproduction of coded pictures. On a video CD, the video data for the PAL system are stored with a resolution of 352*288 pixels at a frame frequency of 25 Hz. The video data for still pictures can be stored either with this resolution or with an increased resolution of 704*576 for the PAL system. Consequently, depending on the specification, for still pictures on a video CD, there may also be a data stream having a mixed resolution in addition to a data stream having a standard resolution. According to the invention, a preliminary analysis is carried out in a first step. After the identification of pictures Nres having the first resolution, these pictures are either skipped or their contents are stored in a buffer. After the identification of pictures Hres having the second resolution, these are fed to a decoding stage.

Abstract: The invention relates to a digital device for detecting the hold by an apparatus of a telephone line into which is plugged a modem employing band superposition transmission, the modem sending a send signal on the telephone line and receiving from this line a digitized reception signal, characterized in that the said device comprises: a means for providing a parameter of the transfer function of the send signal on the reception signal, the said parameter being characteristic of the presence of at least the said apparatus on the line, control means for controlling the interruption of the exchanges of signals of the modem on the line, the said control being dependent on the said parameter of the transfer function. The invention also relates to the method implemented by the device of the invention, a modem comprising this device and a server of an Internet access provider using such a modem.

Abstract: The invention concerns a method and apparatus for playing an audio track during a faster than 1× speed video trick mode playback of a video presentation. The method begins with the step of retrieving from a storage medium information for producing at least a video portion and a corresponding audio portion of a presentation. The audio portion of the presentation, like most audio sound tracks, includes periods of relative silence. For example, these may occur between words or between dramatic pauses in the dialogue. Audio gating is used to selectively gate the audio portion of the presentation to remove at least a portion of the periods of relative silence. Finally, a remaining part of the audio portion of the presentation is concatenated for playback to remove any gaps after the portion of the periods of relative silence have been removed.

Abstract: A horizontal deflection winding centering circuit includes a Darlington transistor and a diode. The Darlington transistor and diode form a non-linear network that is coupled in series with an inductor. The series arrangement of inductor and non-linear network is coupled in parallel with a horizontal deflection winding. The base voltage of the Darlington transistor is produced by a voltage divider coupled in a current path of the inductor current.