Abstract: A signal switch comprises a switch arrangement for selectively passing optical wireless communication, OWC, signals received from a plurality of photodetectors for output to an external device. A signal strength detector is arranged to measure a signal strength of OWC signals as passed by the switch arrangement. While an OWC signal received from a first one of the photodetectors with a signal strength is being passed by the switch arrangement, a selection unit controls the switch arrangement to pass a combination of the OWC signal from the first photodetector and the OWC signal from another photodetector, determines a signal strength of the combination of OWC signals, and estimates the signal strength of the OWC signal from the other photodetector based on the signal strength of the OWC signal from the first photodetector and the signal strength of the combination of OWC signals.

Abstract: A monitor device is provided for monitoring a lighting arrangement of lighting elements of unknown electrical load, and a driver using the monitoring arrangement. A set of duty cycles is applied to switches which control sub-sets of lighting elements thereby to create a desired light output. With this desired duty cycle setting, the current for an individual duty cycle period is monitored, in particular to detect variations in a current plateau level within the individual duty cycle period. This is used to determine electrical characteristics or parameters including at least a cable resistance between a power supply unit and the lighting arrangement. A power consumption of the lighting arrangement may then be obtained. This avoids the need to probe the sub-sets of lighting elements individually in order to determine the nature of the load and its power consumption.

Abstract: A signal switch comprises a switch arrangement for selectively passing optical wireless communication, OWC, signals received from a plurality of photodetectors for output to an external device. A signal strength detector is arranged to measure a signal strength of OWC signals as passed by the switch arrangement. While an OWC signal received from a first one of the photodetectors with a signal strength is being passed by the switch arrangement, a selection unit controls the switch arrangement to pass a combination of the OWC signal from the first photodetector and the OWC signal from another photodetector, determines a signal strength of the combination of OWC signals, and estimates the signal strength of the OWC signal from the other photodetector based on the signal strength of the OWC signal from the first photodetector and the signal strength of the combination of OWC signals.

Abstract: A monitor device is provided for monitoring a lighting arrangement of lighting elements of unknown electrical load, and a driver using the monitoring arrangement. A set of duty cycles is applied to switches which control sub-sets of lighting elements thereby to create a desired light output. With this desired duty cycle setting, the current for an individual duty cycle period is monitored, in particular to detect variations in a current plateau level within the individual duty cycle period. This is used to determine electrical characteristics or parameters including at least a cable resistance between a power supply unit and the lighting arrangement. A power consumption of the lighting arrangement may then be obtained. This avoids the need to probe the sub-sets of lighting elements individually in order to determine the nature of the load and its power consumption.

Abstract: A lighting unit which includes a driver, a light source and a buffer capacitor of an auxiliary circuit (such as an independent active electronic circuit). The charging current allowed to flow to the buffer capacitor is controlled based on sensed currents flowing to the light source thereby to control the charging current of the buffer capacitor. In this way, large inrush currents caused by the use of a large buffer capacitor at the output of the driver can be avoided and the triggering of a fault detection mode within the driver can be prevented. Furthermore this circuit ensures that the driver is operated within the specification limits during start-up.

Abstract: A lighting unit which includes a driver, a light source and a buffer capacitor of an auxiliary circuit (such as an independent active electronic circuit). The charging current allowed to flow to the buffer capacitor is controlled based on sensed currents flowing to the light source thereby to control the charging current of the buffer capacitor. In this way, large inrush currents caused by the use of a large buffer capacitor at the output of the driver can be avoided and the triggering of a fault detection mode within the driver can be prevented. Furthermore this circuit ensures that the driver is operated within the specification limits during start-up.

Abstract: The invention provides a current modulating circuit, for example for use in a driving circuit for driving a lighting load such as an LED arrangement. A current modulating element is provided in series with the lighting load, and modulates the current based on a data input signal. A feedback system controls the current modulating element, and it has a first feedback control path which uses a voltage across the current modulating element, and a second feedback control path which uses the data input signal. The voltage feedback is used to maintain the overall current equal to the current output from a driver. The difference in current is taken up by a capacitor at the output of the driver.

Abstract: An illumination source comprises an array of light-emitting elements for emitting illumination to illuminate an environment. A controller is arranged to control the illumination emitted by different ones of the light-emitting elements so as to form a spatial pattern, and to vary the spatial pattern according to a spatial dimming function whereby the spatial pattern is varied so as to emit a different overall intensity level as a function of a received dimming signal. A value is determined of at least one property relating to a manner in which the illumination source is deployed (e.g. the manner in which it is installed), and the spatial dimming function is set in dependence on the value of this property.

Abstract: An illumination source comprises an array of light-emitting elements for emitting illumination to illuminate an environment. A controller is arranged to control the illumination emitted by different ones of the light-emitting elements so as to form a spatial pattern, and to vary the spatial pattern according to a spatial dimming function whereby the spatial pattern is varied so as to emit a different overall intensity level as a function of a received dimming signal. A value is determined of at least one property relating to a manner in which the illumination source is deployed (e.g. the manner in which it is installed), and the spatial dimming function is set in dependence on the value of this property.

Abstract: The invention provides a current modulating circuit, for example for use in a driving circuit for driving a lighting load such as an LED arrangement. A current modulating element is provided in series with the lighting load, and modulates the current based on a data input signal. A feedback system controls the current modulating element, and it has a first feedback control path which uses a voltage across the current modulating element, and a second feedback control path which uses the data input signal. The voltage feedback is used to maintain the overall current equal to the current output from a driver. The difference in current is taken up by a capacitor at the output of the driver.

Abstract: In order to provide means for measuring vital signs such as heart rate, breathing rate, pulse forms, that allow accurate and unobtrusive signal acquisition and that are automatically adjusted to varying positions of an area of interest within a pre-determined area, a device, a system and a method for measuring vital signs are provided, wherein electromagnetic signals such as microwave or radar are emitted and reflected electromagnetic signals are sensed with directional sensitivity by a transceiving unit and wherein a direction of interest is determined based on the sensed reflected signals and a primary direction of sensitivity (300) of the transceiving unit is adjusted to the direction of interest by a control unit. Thus, vital signs can be monitored in an unobtrusive and simple way.

Abstract: A multi-primary display with more than three additive primaries comprises a spatial repetition of a pixel repetition block. The block comprises a first pixel row (1201) of pixels of primaries. Each pixel is divided into a plurality of sub-pixels including at least a higher luminance sub-pixel adjacent to a lower luminance sub-pixel. The first pixel row (1201) forms a first sub-pixel row (1203) and a complementary sub-pixel row (1205) adjacent to each other and comprising complementary sub-pixels. The sub-pixels are arranged such that a difference between a first combined maximum luminance for higher luminance sub-pixels of the first sub-pixel row (1203) and a second combined maximum luminance for higher luminance sub-pixels of the complementary sub-pixel row (1205) is no more than 30% of a sum of the first combined maximum luminance and the second combined luminance. The invention may provide an improved display with e.g. reduced pixel structure visibility.

Abstract: This invention relates to a method for driving a display panel (DP) having pixels (P). The display panel (DP) is driven with a sequence of image frames. The image frames are converted to a drive signal (V2) comprising refresh frames with a refresh frame period (TR) shorter than the image frame period. A pixel (P) of the display panel (DP) is driven with an adapted drive signal having a first polarity during a first group of refresh frame periods, and having a reversed polarity during a subsequent second group of refresh frame periods. The first group and the second group each comprise at least two refresh frame periods.

Abstract: A method for displaying images on a display having backlight is disclosed, where the images is updated periodically with a period. The method comprises the steps of: generating a signal with a pulse pattern for each period depending on the contents of an image to be displayed in that period; and activating backlight in accordance with the signal. Further, a display (100) comprising a display panel (102) and a backlight unit, wherein the backlight unit comprises a controller (104) and a lighting device is disclosed. The controller (104) is arranged to generate a control signal, and the lighting device is arranged to provide backlight to the display panel (102) according to the control signal, wherein the control signal comprises a pulse pattern depending on contents of displayed images.

Abstract: This invention relates to driving a liquid crystal display with a polarity inversion. The liquid crystal display panel (98) comprises a matrix of pixels (52, 62, 72), which is driven with a sequence of image frames. The method comprises driving the pixels during a first frame (n?1) with a first polarity pattern; driving the pixels with exception of a first set of pixels (54, 66, 74) during a second frame (n) with an inverted polarity pattern; and driving the first set of pixels (54, 66, 74) with the inverted polarity pattern during a third frame (n+1).

Abstract: This invention relates to a method for driving a display panel (DP) having pixels (P). The display panel (DP) is driven with a sequence of image frames. The image frames are converted to a drive signal (V2) comprising refresh frames with a refresh frame period (TR) shorter than the image frame period. A pixel (P) of the display panel (DP) is driven with an adapted drive signal having a first polarity during a first group of refresh frame periods, and having a reversed polarity during a subsequent second group of refresh frame periods. The first group and the second group each comprise at least two refresh frame periods.