摘要:
A string of LED loads is supplied by means of a rectified mains voltage. A cathode of each LED load is coupled to ground by means of a string. The strings are made conductive and non-conductive one by one in dependency of the instantaneous value of the rectified mains using both voltage and current sensing.
摘要:
There is provided an arrangement for spot illumination (14). The arrangement provides an improved collimation and color mixing unit comprising a LED array (1), a convex shaped reflector (15a), a field lens (21) and an additional cylindrical reflector (15b) at the exit aperture of the system. In combination with an optical projection system which may comprise at least two additional zoom lenses and a gate (in which several maskers, gobos or shutters could be inserted) the system allows color mixing in an extended operational range including out of focus zoom settings often used to get soft edge spots.
摘要:
LED light source suitable for use with a phase cut dimmer (III), comprising •input terminals (K1, K2) for connection to an AC supply voltage, •a rectifier (I) coupled to the input terminals, 108 a series arrangement comprising N LEDs (LL1, LL2, LL3) coupled to the rectifier, •control circuitry (EX) for sequentially activating (deactivating) the LEDs as the supply voltage increases (decreases), wherein the control circuitry comprises: •N controllable current regulators, each regulator being coupled between the cathode of a LED and ground and comprising a transistor and one impedance in series, •a global current control circuit (X) coupled to the control electrodes of said transistors and comprising circuitry for adjusting the voltage at said control electrodes in dependency of the phase angle, •a series arrangement of a switch (S) and a capacitor (C1) coupled- to the rectifier and •means (VIII) for rendering said switch conductive in case the AC supply voltage drops below a reference value.
摘要:
LED light source comprising a string of LED loads (LED1-LED4) supplied by a rectified mains voltage. The number of LED loads carrying current is increased as the momentary amplitude of the rectified mains voltage increases, and is decreased as the momentary amplitude of the rectified mains voltage decreases. The order in which the LED loads start carrying a current and the order in which the LED loads stop carrying a current is reversed for each half period of the mains.
摘要:
An illumination system (10) for spot illumination comprising a tubular reflector (2) with a reflective inner surface, the tubular reflector (2) having an entrance aperture (7) and an exit aperture (8) being larger than the entrance aperture (7); and a light-source array (1) comprising a plurality of light-sources (13a-c; 30a-d, 31a-d, 32a-d) arranged to emit light into the tubular reflector (2) at the entrance aperture (7) thereof. At least one of the tubular reflector (2) and the light-source array (1) is configured in such a way that each symmetry state of the light-source array (1) is different from any symmetry state of the tubular reflector (2). By avoiding coinciding symmetry states, the occurrence of preferred directions of the emitted light can be reduced, whereby the spatial homogeneity with respect to intensity and, where applicable, color of the emitted light can be improved.
摘要:
It is an object of the invention to provide for an alternative for analyzing fluids. To this end a device for analyzing fluids comprising magnetic particles is provided, the device comprising magnetic means for generating a magnetic field designed for exerting a magnetic force to the magnetic particles creating a movement of the fluid comprising targets and a membrane with an array for moving the fluid through or along the array.
摘要:
The present invention relates to a hydrogel-containing temperature indicating element for use in ultrasound therapy. The temperature indicating element of the present invention and the therapeutic device and method making use of the same enable in some embodiments an automated adaptation of the power output as a function of the tissue temperature, avoiding therefore overheating or burning of the skin.
摘要:
A light-emitting diode has a first electrode, a second electrode and a light-emitting layer. A receptor layer of an ion receptor has an affinity for ions of a first charge and is positioned between the first electrode and the light-emitting layer. A further layer includes immobile ions of a second charge and is positioned between the second electrode and light-emitting layer. The immobile ions initially have attached counterions of the first charge that move towards the receptor layer upon application of an electric field for capture by the receptor layer. Upon capture of the counterions, a concentration of immobilized ions of the first charge is formed at the first electrode yielding an ion gradient for injection of electrons and holes resulting in emission of light.
摘要:
The present invention provides a microf luidic device, for instance for molecular sieving or for detecting a target substance in a sample fluid. The device comprises a first substrate (120) having a substantially flat first surface that is provided with first recesses (124), and a second substrate (128) having a substantially flat second surface that is provided with second recesses (130). At least some of the first recesses are filled with a porous material (114). Alternate first recesses and second recesses form a meandering channel for a sample fluid. The second recesses may be filled with a further porous material. In an embodiment, a capture substance for binding a target substance is arranged in or on the porous material.
摘要:
The present invention relates to a method for illuminating a scene having an average lighting setting, the method comprising the steps of receive scene information from an image sensor (110) comprising a plurality of pixels, determine chromaticity coordinates for the scene based on the scene information, and determine, based on the chromaticity coordinates, control values used for driving the at least two differently colored light sources (L1, L2, L3), thereby allowing for illumination of the scene without essentially changing the average lighting setting of the scene. The present invention provides for the possibility to in a more precise way match the average lighting setting of the scene, wherein it is possible to produced light that assure a more natural rendering of illuminated objects in the scene. In comparison to the prior art, for light sources which have spectra far from the black body curve, the chromaticity coordinates are a better representation of the color of ambient light illuminating the scene than when using the correlated color temperature. The present invention also relates to a corresponding illumination device (100).