摘要:
This invention describes a method for driving a gas discharge lamp (1), whereby an alternating voltage (U) is applied to the gas discharge lamp (1), the alternating voltage (U) having a first polarity during a first time interval (tf1, ts1) and a second polarity opposite to the first polarity during a second time interval (tf2, ts2). In this method, the first time interval (tf1) and the second time interval (tf2) are repeated alternately during a first operation mode. During a second operation mode, the electrical power (P) being provided to the gas discharge lamp (1) is smaller compared to the first operation mode, and the first time interval (ts1) and the second time interval (ts2) are repeated alternately, whereby in this second operation mode the duration of the first time interval (ts1) is at least a multiple of the duration of the second time interval (ts2). Furthermore, the invention describes an appropriate driving unit (4) for driving a gas discharge lamp (1), and an image rendering system, particularly a projector system, comprising a gas discharge lamp (1) and such a driving unit (4).
摘要:
Disclosed is a method for driving a gas discharge lamp in at least two operation modes, including the step of applying an alternating voltage to the gas discharge lamp, the alternating voltage having a first polarity during a first time interval and a second polarity opposite to the first polarity during a second time interval. The first time interval and the second time interval are repeated alternately. During a second operation mode, the electrical power being provided to the gas discharge lamp is smaller compared to a first operation mode, and the duration of the first time interval is at least a multiple of the duration of the second time interval.
摘要:
The invention describes a method of shutting down a high pressure discharge lamp (1) in which a pair of electrodes (2) is disposed in an arc tube (3), which method comprises reducing, upon receipt of a shut-down request (SR), the lamp power (P) towards a reduced power level (PR) required to sustain a long-term arc discharge between the electrodes (2), and driving the lamp (1) towards the reduced power level (PR) for a reduced power duration before completely shutting down the lamp power (P), whereby, prior to reducing the lamp power (P) towards the reduced power level (PR), the lamp power (P) is reduced to an undershoot power level (Pu), which undershoot power level (Pu) is lower than the reduced power level (PR) required to sustain a long-term arc discharge between the electrodes (2), and the lamp is driven at this undershoot power level (Pu) for an undershoot power duration (tu) before increasing the lamp power (P) again to approach the reduced power level (PR). Moreover the invention describes an appropriate driving unit (4) for driving a high pressure discharge lamp (1) and an image rendering system (40), particularly a projector system, comprising such a driving unit (4).
摘要:
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.
摘要:
The invention describes a method of shutting down a high pressure discharge lamp (1) in which a pair of electrodes (2) is disposed in an arc tube (3), which method comprises reducing, upon receipt of a shut-down request (SR), the lamp power (P) towards a reduced power level (PR) required to sustain a long-term arc discharge between the electrodes (2), and driving the lamp (1) towards the reduced power level (PR) for a reduced power duration before completely shutting down the lamp power (P), whereby, prior to reducing the lamp power (P) towards the reduced power level (PR), the lamp power (P) is reduced to an undershoot power level (Pu), which undershoot power level (Pu) is lower than the reduced power level (PR) required to sustain a long-term arc discharge between the electrodes (2), and the lamp is driven at this undershoot power level (Pu) for an undershoot power duration (tu) before increasing the lamp power (P) again to approach the reduced power level (PR). Moreover the invention describes an appropriate driving unit (4) for driving a high pressure discharge lamp (1) and an image rendering system (40), particularly a projector system, comprising such a driving unit (4).
摘要:
Driver circuits (1) for driving load circuits (2, 3) receive source signals from sources and provide feeding signals to the load circuits (2,3) and charging signals to capacitor circuits (21). These capacitor circuits (21) provide supporting signals to the load circuits (2, 3) in addition to the feeding signals. By providing the driver circuits (1) with control circuits (22) for controlling the supporting signals, the capacitor circuits (21) can become less bulky/costly and/or will limit the lifetime of the driver circuits (1) to a smaller extent. Further, these driver circuits (1) may get improved efficiencies. Said controlling may comprise controlling moments in time at which the supporting signals are offered to the load circuits (2, 3) or not, and/or may comprise controlling sizes of the supporting signals, and/or may be done in response to detection results from detectors (23) for detecting parameters of one or more signals. Said controlling may comprise switching via switches (24).
摘要:
Driver circuits (1) for driving load circuits (2) comprising first and second light circuits (21-22, 71-72) are in first/second modes for input voltages having first/second voltage amplitudes, the second voltage amplitudes being larger than the first voltage amplitudes. The first light circuits (21, 71) are on in the first and second modes. The second light circuits (22, 72) are off in the first modes and are on in the second modes. A control circuit (21, 71) in dependence of the modes to extend control. These currents may get smaller current amplitudes in higher modes. Light outputs of the first light circuit (21, 71) may get smaller in higher modes. A total light output of all light circuits (21-22, 71-72) may remain substantially constant during all modes.
摘要:
An image projection method comprises the steps of a) obtaining an image pixel array for the image to be projected; b) obtaining a plurality of pixel allocation arrays for the image pixel array, whereby each pixel allocation array comprises occupied elements and vacant elements; c) generating a trigger pulse train for a laser light source according to a pixel allocation array, whereby a trigger pulse is generated for each occupied element; d) generating a modulation signal for the laser light source; e) switching the laser light source with the trigger pulse train and modulating the laser light source with the modulation signal to generate a laser light pulse sequence for a sub-frame image; f) and scanning the laser light pulse sequence to traverse the display; thereby, the steps c) to f) are carried out for each pixel allocation array so that the image appears on the display.
摘要:
Supply circuits for supplying voltage and current signals to light sources (6) comprise switches (22, 32, 42, 52) and controllers (21, 31, 41, 51) to control the switches (22, 32, 42, 52) for reducing values of frequency components of harmonic content of power spectra of the light sources (6). By switching one of the voltage and current signals or by switching signals that result in one of the voltage and current signals, the other one of the voltage and current signals can be adjusted. The power spectrum of the light source (6) may be a function of the voltage and current signals. By adjusting one of them, the power spectrum can be adjusted such that values of frequency components of the harmonic content of the power spectrum are reduced. As a result, visible flicker is reduced in the light originating from the light source (6) without the use of energy storage capacitors for reducing this visible flicker.
摘要:
The invention relates to a circuit (2) comprising at least two parallel-connected light-emitting diodes (4, 5) opposite poled in a first parallel branch (12) and comprising at least two parallel-connected light-emitting diodes (6, 7) opposite poled in a second parallel branch (13), and also comprising a capacitor (8) and a coil (9). According to the invention, the first parallel branch (12) has a capacitor (8) and the second parallel branch (13) has the coil (9). On account of the capacitive parallel branch (10) and the inductive parallel branch (11), idle currents arise which are phase-shifted with respect to one another. The idle currents compensate one another and light changes of the oppositely-poled diode pairs take place at different points in time. A light current is then smoothed.