摘要:
According to an exemplary embodiment of the present invention, a lighting system for communication with a remote control device is provided, which comprises a light emitting element adapted for emitting modulated light to the remote control and for detecting control signals from the remote control. This may provide for a communication between the remote control and the lighting system without the need of an extra sensor or an extra transmitter.
摘要:
According to an exemplary embodiment of the present invention, a lighting system for communication with a remote control device is provided, which comprises a light emitting element adapted for emitting modulated light to the remote control and for detecting control signals from the remote control. This may provide for a communication between the remote control and the lighting system without the need of an extra sensor or an extra transmitter.
摘要:
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).
摘要:
A lighting device, and a lighting system including such a lighting device and an adjustable power source, includes at least one LED, a control device employing a device for measuring a quantity that is indicative of an electrical resistance of the LED at a predetermined current or voltage, a power supply control device for controlling an adjustable electrical power supply for driving the LED. The electrical resistance of a LED is functionally dependent of the LED's junction temperature, which in turn determines its optical output characteristics. Thus, by measuring the junction temperature indirectly, through measuring of electrical LED characteristics, and mapping them to a temperature, LED output control is possible.
摘要:
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.
摘要:
In a method and a driver circuit for operating one or more light emitting diodes, LEDs, an alternating supply current is generated and transformed to an alternating secondary winding voltage. Using rectifier means, such as diodes or synchronous switches, the alternating secondary winding voltage is converted to a substantially constant load current by using a buffer element, such as an output choke, i.e. a suitable inductor. The power transferred from the power source to the LEDs may be controlled by frequency control of the alternating supply current.
摘要:
A driver circuit for operating one or more light emitting diodes(LEDs) is disclosed. An alternating supply current is generated and transformed to an alternating secondary winding voltage. Using rectifier means, such as diodes or synchronous switches, the alternating secondary winding voltage is converted to a substantially constant load current by using a buffer element. The buffer element comprises an output choke, such as an inductor. The power transferred from the power source to the LEDs may be controlled by frequency control of the alternating supply current.
摘要:
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.
摘要:
The present invention relates to a method for controlling an illumination device (100), the illumination device (100) comprising a flux sensing unit (101) and at least two differently colored light sources (102, 103, 104), the method comprising the steps of switching on and off each of the light sources according to a predefined pattern, acquiring measurement values by means of the flux sensing unit at predetermined intervals in accordance with the predefined pattern, calculating a color point for each of the light sources based on the measurement values, calculating a difference between the color points and corresponding reference color points, and adjusting an analog current drive level of the light sources, wherein the difference is minimized such that a desired color is obtained. The present invention provides for the possibilities to in a more accurate way correct for the color changes due to change in drive current, temperature, and aging effects. Furthermore, the control method according to the present invention does not require a factory calibration, or knowledge of batch specific binning information, for obtaining the current or temperature related characteristics of the light sources, which significantly reduces the cost normally related to factory calibration and batch specific binning information. Furthermore, the present invention relates to an illumination device (100) comprising means for performing such a method.
摘要:
The present invention relates to a lighting device, as well as to a lighting system comprising such a lighting device and an adjustable power source, and also relates to a method of driving such a lighting system. The lighting device comprises at least one LED (1a, 1b), a control device that comprises a measuring means (7, 9) to measure a quantity that is indicative of an electrical resistance of said LED at a predetermined current or voltage, a power supply control means (11) connected to said measuring means (7, 9) and constructed to control an adjustable electrical power supply (3a, 3b) for driving the LED (1a, 1b), said signal being based on said value of said quantity. The electrical resistance of a LED is functionally dependent of the LED's junction temperature, which in turn determines its optical output characteristics. Thus, by measuring the junction temperature indirectly, through measuring of electrical LED characteristics, and mapping them to a temperature, LED output control is possible.