摘要:
The invention describes a method of driving a discharge lamp (1) in a projection system (10), wherein, in a feed-forward control process, system status data (SDL, SDF, SDV) comprising static information pertaining to the design of the system and/or dynamic information pertaining to the projection system and/or dynamic information pertaining to the lamp operation are obtained. Based on the system status data (SDL, SDF, SDV), a momentary target light waveshape (LWT, LWT′) required by the projection system (10) and a waveshape correcting function are determined. Subsequently, the actual current (I) of the discharge lamp (1) is controlled regulated according to a momentary required waveshape (RW) which is determined based on the target light waveshape (LWT, LWT′) and the waveshape correcting function. Moreover the invention describes an appropriate driving unit (11) for driving a discharge lamp (1) and a projection system (10), comprising such a driving unit (11).
摘要:
The present invention relates to a method of operating a projection system comprising several solid state light sources (2, 3, 4) of different colour 13, 14, 15) and at least one spatial light modulator (1) having an array of switchable elements. Said array is illuminated by at least one of said light sources (2, 3, 4) for several illumination periods and is addressed such that the light is timely and spatially modulated to project images onto a screen. In the present method said light sources (2, 3, 4) are controlled to emit light modulated in amplitude (15) and/or time (18) during said illumination periods of said array. With the present method an increased greyscale resolution of the projection system can be achieved.
摘要:
A scanning backlight unit (BU) for a matrix display comprises a plurality of light sources (L1, . . . , Ln). A driver (2) supplies drive signals (D1, . . . , Dn) to the light sources (L1, . . . , Ln). A controller (3) controls the driver (2) to separately activate the light sources (L1, . . . , Ln) to obtain light-emitting regions (5) being active. A light sensor (4) is associated with a group of at least two of the light sources (L1, . . . , Ln) to supply a sensor signal (SES) which indicates a luminance (LU) of the group. The controller (3) reads the sensor signal (SES) at different instants (ts1, . . . , tsn) at which mutually different subsets of the light sources (L1, . . . , Ln) of the group are active to control the driver (2) to supply power levels to the light sources (L1, . . . , Ln) of the group to obtain a luminance (LU1, . . . , LUn) of each one of the light sources (L1, . . . , Ln) of the group in dependence on the sensor signal (SES).
摘要:
The invention relates to a method and an arrangement (10) for monitoring a gas discharge lamp (22), comprising a control circuit (18) for detecting an electrical measured value assigned to the lamp voltage. The control circuit (18) is provided for detecting one voltage value prior to a change in current and a second voltage value after a change in current, or a setting time, and for producing a control signal which depends on the difference in the voltage values or on the setting time. In this way, a pressure within the lamp is monitored and a control signal can be produced which can be used to cool the lamp or to switch the lamp off. This methods detects inflation and therefore prevents an explosion of the lamp.
摘要:
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.
摘要:
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 artifacts is made possible by the second pulses (P2, P4, P20, P30, P50, P60).
摘要:
A projection system for image representation includes a display, a lamp, and a sensor for generating a sensor signal for monitoring and compensating changes in the luminous flux provided by the lamp. To achieve a monitoring of the light quantity actually incident on the display, an optical component is arranged in a light path between the lamp and the display. The optical 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 and the other light component is directed at the sensor arranged outside the light path. A sensor signal generated in this manner renders it possible to compensate for fluctuations in the luminous flux provided by the lamp through the control of a lamp driver in an effective.
摘要:
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).
摘要:
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.
摘要:
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.