Abstract:
An electroluminescent device (7) comprising at least one electroluminescent light source (2) and at least one electronic component (3) for driving the electroluminescent light source (2), which electronic component (3) is arranged in such a way as to be separated in space from the electroluminescent light source (2), the electrical connection between the electroluminescent light source (2) and the electronic component (3) being made by a flexible film (8) having electrically conductive regions (82) and at least one electrically insulating surface (81).
Abstract:
The invention relates to a driver circuit arrangement (1') for driving a plurality of individually switchable electrical subsystems (A', B', C'), such as (arrangements of) LEDs (9-A, 9-B, 9-C). Each subsystem has at least one energy storage device (10-A, 10-B, 10-C), such that when the subsystem is disconnected from the main source (7) of electrical energy, the energy storage device can supply energy to the device(s) of the subsystem. By furthermore providing at least one subswitch (13-A, 13-B, 13-C) in the subsystem, between the energy storage device and an electrical device of the subsystem, control over the device is still possible when the subsystem is disconnected form the main source of electrical energy.
Abstract:
A wireless resonant powering device (1) according to the invention comprises a first inductor winding (3), which is arranged to form a transformer (9) with the inductor winding (13) of the energizable load (11). The first inductor winding (3) is arranged to form a resonant circuit (5), which may comprise a suitable plurality of electric capacitances and coils. The components of the resonant circuit (5) are selected such that the magnetic energy received by the inductor winding (13) damps the energy flow in the resonant circuit so that the induced voltage in the inductor winding (13) is substantially constant and is independent of the magnetic coupling between the first inductor winding (3) and the inductor winding 13 at the operating frequency of the driving means (6). The resonant circuit is driven by the driving means (6), comprising a control unit (6c) arranged to induce an alternating voltage between a first semiconductor switch (6a) and a second semiconductor switch (6b). At the output of the transformer (9) an alternating voltage is generated, which is rectified to a DC-voltage by a diode rectifier, filtered by an output capacitance. The resonant circuit (5) is operable on its coupling independent point by the driving means (6). This figure schematically illustrates a situation, where a variable coupling between the first inductor winding (3) and the inductor winding (13) exists. The invention further relates to a wireless inductive powering device, an energizable load, a wireless system and a method for wireless power transfer.
Abstract:
The invention relates to a photo-detector comprising a light sensitive element (101) and a wavelength converter (103) arranged in front of the light sensitive element, the wavelength converter being configured to convert light of a first wavelength into light of a second wavelength and to direct the light of the second wavelength to the light sensitive element. The advantage is that a stable reading across the entire visible spectrum may be provided.
Abstract:
The present invention relates to a device and method for controlling the color point of an LED light source (50). Color point control is a most interesting product feature both for white and colored LED light sources. In known methods for the color control of RGB LED light sources use is made of flux and color sensors. However, there are difficulties with respect to sensing quickly changing ambient light, deeply dimmed colors, coordinating the measurements with the switching of the LEDs, and controlling the color in LED light units comprising a number of independent LED lamps, e.g. segmented wall washers and LCD backlights. It is proposed according to the present invention to control the color of the LED light source (50), using a model-based feed forward approach. Factors relating the parameters controlling the LED currents to the brightness for the different colors (and segments) are stored and used for open loop control. A slow-running procedure continuously measures and updates these factors. Whilst the measurements are e.g. synchronized with the PWM, the procedure itself can run considerably slower and updates the factors asynchronously.
Abstract:
First, light-sensing devices (1) comprise sensors (11) for sensing light (3) originating from second, light-generating devices (2) and for generating sensing results and comprise generators (12) for generating information (4) in response to the sensing results and comprise transmitters (13) for wirelessly transmitting the information (4) to the second devices (2). The second devices (2) comprise lightsources (21) for generating the light (3) and comprise drivers (22) for driving the light sources (21) and comprise receivers (23) for wirelessly receiving the information (4) for adapting the driving of the light sources (21). The first devices (1) may be self-powered devices and may comprise converters (31) for converting the light (3) for feeding the first devices (1). The light sources (21) may comprise one or more light emitting diodes.
Abstract:
Operating a lighting device by acquiring a target brightness level of at least one solid-state lighting unit, and determining a reference driving current amplitude for obtaining the target brightness level. If the reference driving current amplitude is below an optimum driving current amplitude, the solid-state lighting unit is operated at the optimum driving current amplitude, which is pulse-width modulated to obtain the target brightness level.
Abstract:
The invention relates to a lighting device that may particularly be used as an LCD backlight and that comprises an array of light emitters (11.1, 11.2) which are optionally separated by optical barriers (13). The light emitters (11.1, 11.2) may particularly be realized by groups of LEDs (12.1, 12.2) of different colors, for example red, green and blue. Local control units (16), driving units (15.1, 15.2), and sensor units (14) are provided to control the individual light output of the light emitters, wherein at least one of these components is shared by two or more light emitters (11.1, 11.2).