Abstract: The invention describes a method of transmitting information between an information transmitter and an information receiver, the potential difference of which moves in cycles between a minimum value and a maximum value and is situated at the minimum value for regular intervals; having the steps: provision of information over the time interval or determining the time interval in which the potential difference between information transmitter and information receiver assumes its minimum value; closing of a switching means of the information transmitter in relation to an information memory assigned to the information receiver, only within the time interval; and transmission and storage of the information in the information memory.

Abstract: A projection system for image display with at least one lamp (1), with at least one sensor (5) for detecting changes in the luminous flux delivered by said at least one lamp (1) and for compensating these changes through a suitable control of the image display and/or the lamp is described. The projection system is remarkable in that a light integrator (3) is provided, into which at least a portion of the light provided by the lamp (1) is coupled in, while the sensor (5) is optically coupled to the light integrator (3) such that it detects the luminous intensity present in the light integrator (3). Since this luminous intensity is very homogeneous because of the multiple reflections and is not influenced by brightness fluctuations caused by an optical component such as, for example, a color modulator (4), a very accurate compensation of changes in the luminous flux generated by the lamp (1) is made possible by the sensor signal.

Abstract: A control unit (2) of a remote control receiver sets the forward or reverse direction operating mode of the photodiode (1) as a function of the useful signal level of its output signal, and to be precise, during standby, the photovoltaic operating mode (forward mode), since in this mode no external bias current is required. If the useful signal level of the photodiode (1) exceeds a predefined threshold, the reverse mode is set, and this brings with it a higher sensitivity. A series circuit (A) of a number of identical photodiodes DA1 DAn in the forward mode allows the realization of a controlled current source (6) having a transistor (T), since the permissible diode voltage (Ud) of the overall arrangement may have n times the value of the operating voltage of an individual photodiode. Thus at the same time the voltage across the individual diodes can be set to a very low value and a favorable operating range for the current source can be set.

Abstract: In order to improve the efficiency of a driver circuit for controlling upper and lower switching means (T3, T4) for converting a direct voltage Ud into a clocked output voltage Ua for a resonant converter with a high-voltage section (HT) for controlling the upper switching means (T3) and a low-voltage section (NT) for controlling the lower switching means (T4), which switch the switching means (T3, T4) on alternately to one another, the switch-on phases of the switching means (T3, T4) being separated from one another by dead-time phases, there is provided a first circuit section which controls the duty cycle ?tein3 of the upper switching means (T3) as a function of the duty cycle ?tein4 of the lower switching means (T4), and receives control signals from the low-voltage section (NT) exclusively during the duty cycle ?tein4 of the lower switching means (T4).

Abstract: In the case of known switched-mode power supplies with integrated preconditioner, the control curves are largely congruent, but deviate from one another in low-load operation, whereby the unregulated intermediate circuit voltage increases. To improve efficiency in low-load operation, closed-loop control of the burst cycle is effected on the primary side of the voltage transformer. The intermediate circuit voltage is limited to a permissible limit value. The closed-loop control device in the switching stage taps the intermediate circuit voltage at a voltage divider which is arranged between the preconditioner functional unit and the switching stage. An assembly additionally monitors the output voltage, for example by means of an optocoupler. Burst mode comprises one or more burst cycles. A burst cycle is started when the intermediate circuit voltage reaches its limit value. At this time, the voltage transformer is switched off. A burst cycle ends when the output voltage reaches a minimum value.

Abstract: The invention relates to a method of representing a video image based on a video signal by means of a projector which comprises an image display device and a high-pressure gas discharge lamp, which lamp is supplied with a square-wave alternating current (I0, I10) on which a current pulse (P1, P3, P10, P40) is superimposed before each phase reversal. According to the invention, the alternating current (I0, I10) is superimposed with a second current pulse (P2, P4, P20, P30, P50, P60) of the same polarity. A simple attunement of the alternating current frequency to the image frequency without image artefacts is made possible by the second pulses (P2, P4, P20, P30, P50, P60).

Abstract: The invention relates to a projection system for image representation, with a display (61), at least one lamp (10), and at least one sensor (7) for generating a sensor signal for monitoring and compensating changes in the luminous flux provided by the at least one lamp (10). To achieve a monitoring of the light quantity actually incident on the display (61) which is as accurate and as interference-free as possible, an optical component (31) is arranged in a light path between the lamp (10) and the display (61), which component allows a first light component to pass through and reflects a second light component such that one of the light components is directed at the display (61) and the other light component is directed at the sensor (7) arranged outside the light path.

Abstract: A projection system for image reproduction by means of at least one lamp (10) as well as a sensor (30) for generating a sensor signal for monitoring changes in the luminous flux generated by said at least one lamp (10) and for compensating these changes through a suitable control of the image reproduction is described. The projection system comprises a device (31; 32; 36, 37) for eliminating substantially periodic interference components from the sensor signal generated by the at least one sensor (30; 301, 302, 303). These interference components may be generated by an optical component such as in particular a color modulator (12) of the projection system. The invention thus renders possible an at least substantially interference-free compensation of fluctuations in the luminous flux generated by the lamp (10), for example owing to an unstable arc discharge, also in those color systems in which the positioning of the sensor (30) in the projection system is non-critical.

Abstract: A circuit arrangement is described for a microcontroller having an improved energy consumption which is achieved in that the microcontroller (2) is connected to its operating clock only during evaluation of a signal. A switching means (5) through-connecting the operating clock when a “logic 1”, signal is present at the control input is arranged between the microcontroller (2) and the clock generator (6). This “logic 1” signal is generated by setting a flip-flop (4, 7) for example, when receiving a remote control signal. The program run of the microcontroller (2) is stopped at a defined breakpoint so that there is no transient time.

Abstract: The invention relates to a method for operating a discharge lamp 11 including two electrodes 12,13. The method comprises applying to the electrodes an alternating current ILamp. In order to improve the performance of the lamp and to increase the life time of the lamp, it is proposed that the alternating current has a direct current component DC for compensating a temperature difference between the two electrodes. The direct current component is selected more specifically such that a first electrode, which is expected to have a lower temperature than the second electrode, functions as anode for the direct current component, while the second electrode functions as cathode for the direct current component. The invention relates equally to an electronic circuit and to a software program for operating a discharge lamp correspondingly, as well as to a lighting system comprising a discharge lamp and means for operating this discharge lamp correspondingly.

Abstract: The invention relates to an image projector with a High-Intensity-Discharge HID lamp (112) and a method of operating it. Such lamps have the disadvantage that their voltaic arc jumps back and forth between different positions at unforeseeable times during operation. This so-called arc jumping has the effect of changing the brightness, i.e. the overall brightness and/or the brightness distribution of the light emitted by the HID lamp (112). For the viewer of an image projected with such a projector, this effect appears as a jolt of this projected image. To avoid such effects for the viewer, it is first proposed according to the invention that changes in the brightness of the light in the image projector's beam path are detected. As soon as a change in brightness caused by an arc jump has been detected, this brightness is reset to a brightness detected at a moment t-2 before the arc jump, in order subsequently to convert it during a predetermined time interval T to the brightness resulting from the arc jump.

Abstract: The invention relates to a method and a device (1) for data transmission in a power supply network (power line communication). The device (1), preferably centrally located in a distribution box (6), is equipped with transceivers (3, 4, 5), each one of which is connected to a phasing line (11, 12, 13) of the power supply network, from which it can receive data, and to which it can transmit data. The transceivers are coupled via a control unit (2), wherein the control unit ensures that the data received from a phasing line can be transmitted, prepared, on at least one other phasing line. Hereby, a re-transmission on all phasing lines with the same transmission power, or a re-transmission matched to the particular signal strengths or the addressees of the data, can take place.

Abstract: The invention relates to a method for enhancing brightness and contrast in images provided by a projection-based presenter utilising a display panel (5) illuminated by at least one scrolling band of light and a lamp (3) as a light source for said at least one scrolling band of light. In order to enable such an enhancement, it is proposed that the method comprises modulating the light output of the lamp (3) between different scrolling positions in a way that a higher light intensity is supplied by said lamp (3) when parts of the display panel (5) currently representing brighter parts of a respective image are illuminated by said at least one scrolling band of light than when parts of the display panel (5) currently representing less bright parts of said image are illuminated by said at least one scrolling band of light. The invention relates equally to a corresponding projector, and to an image processor and a regulation and controlling system for such a projector.

Abstract: The invention relates to a method and a server (1) for implementation of central standby functions in an (in-home) network with devices (11-16) connected thereto. The standby server (1) contains a central processor (3), a mass memory (4) and interfaces (2, 5, 6) for the network connection. When one of the devices (11-16) is shut down, it sends corresponding information and where applicable data to the server (1) whereupon the latter takes over the standby functions for the device. In particular the server (1) can temporarily store data directed to the device as long as this is switched off, or pass on with time delay data to be transmitted by the device. Centralization of the standby functions in a special server reduces the energy consumption and improves the speed of data transmission.

Abstract: In the case of known switched-mode power supplies with integrated preconditioner, the control curves are largely U congroent, but deviate from one another in low-load operation, whereby the unregulated intermediate circuit voltage increases. To improve efficiency in low-load operation, closed-loop control of the burst cycle is effected on the primary side of the voltage rns- former. The intermediate circuit voltage is limited to a permissible limit value. The closed-loop control device in the switching stage taps the intermediate circuit voltage at a voltage divider which is arranged between the preconditioner functional unit and the switching stage. An assembly additionally monitors the output voltage, for example by means of an optocoupler. Burst mode corn- pnses one or more burst cycles. A burst cycle is started when the intermediate circuit voltage reaches its limit value. At this time, the voltage transformer is switched off. A burst cycle ends when the output voltage reaches a minimum value.

Abstract: A method and a circuit arrangement for the operation of a high-pressure gas discharge lamp (HID [high intensity discharge] lamp or UHP [ultra high performance] lamp) is described, which lamp is particularly suitable for illuminating projection displays with sequential color rendering (for example LCOS or SCR-DMD systems) with a pulsatory lamp current. Artefacts in the color rendering are avoided through the generation of at least one compensation pulse of a given amplitude and a given timing and through superimposition thereof on the lamp current.

Abstract: The invention relates to a coupling module (1) via which communication becomes possible between different electronic appliances of an (in-home) network (30). To this end, the coupling module (1) can be expanded in modular fashion with transmitter and receiver modules (20-27), which in each case create a network interface with the electronic appliances, with the associated transmission protocol in each case. The coupling module (1) may preferably independently detect the connected appliances, and pass on incoming information to the particular addressee in the appropriate protocol.

Abstract: In order to improve the efficiency of a driver circuit for controlling upper and lower switching means (T3, T4) for converting a direct voltage Ud into a clocked output voltage Ua for a resonant converter with a high-voltage section (HT) for controlling the upper switching means (T3) and a low-voltage section (NT) for controlling the lower switching means (T4), which switch the switching means (T3, T4) on alternately to one another, the switch-on phases of the switching means (T3, T4) being separated from one another by dead-time phases, there is provided a first circuit section which controls the duty cycle ?tein3 of the upper switching means (T3) as a function of the duty cycle ?tein4 of the lower switching means (T4), and receives control signals from the low-voltage section (NT) exclusively during the duty cycle ?tein4 of the lower switching means (T4).

Abstract: The invention relates to an image projector with a High-Intensity-Discharge HID lamp (112) and a method of operating it. Such lamps have the disadvantage that their voltaic arc jumps back and forth between different positions at unforeseeable times during operation. This so-called arc jumping has the effect of changing the brightness, i.e. the overall brightness and/or the brightness distribution of the light emitted by the HID lamp (112). For the viewer of an image projected with such a projector, this effect appears as a jolt of this projected image. To avoid such effects for the viewer, it is first proposed according to the invention that changes in the brightness of the light in the image projector's beam path are detected. As soon as a change in brightness caused by an arc jump has been detected, this brightness is reset to a brightness detected at a moment t-2 before the arc jump, in order subsequently to convert it during a predetermined time interval T to the brightness resulting from the arc jump.

Abstract: The invention describes a method of transmitting information between an information transmitter and an information receiver, the potential difference of which moves in cycles between a minimum value and a maximum value and is situated at the minimum value for regular intervals; having the steps: provision of information over the time interval or determining the time interval in which the potential difference between information transmitter and information receiver assumes its minimum value; closing of a switching means of the information transmitter in relation to an information memory assigned to the information receiver, only within the time interval; and transmission and storage of the information in the information memory.