Signify Holding B.v.

Koninklijke Philips Corporation N.v.

Aleksandar Sevo

Haimin Tao

Karnekumar Arulandu

Bartel Marinus Van De Sluis

Johan Paul Marie Gerard Linnartz

Johan-Paul Marie Gerard Linnartz

Kumar Arulandu

Jeroen Hubert Christoffel Jacobus Stessen

Bas Driesen

Joris Hubertus Antonius Hagelaar

Johannes M Van Meurs

Cornelis Antonius Verbakel

Lucas Louis Marie Vogels

Jorge Gabriel Squillace

Christian Jordan

Marcel Van Der Ham

Johannes Maria Van Meurs

A bias circuit () of an avalanche photodiode, APD, comprising: a voltage conversion module () connected to the APD, wherein the voltage conversion module () is configured to convert an input supply voltage (Vin) to a bias voltage for the APD; an error amplifier () connected to the voltage conversion module () for implementing a feedback control; a voltage feedback loop () configured to provide the error amplifier () a first analog signal related to the bias voltage; and a current feedback loop () configured to provide the error amplifier () a second analog signal related to the APD current; wherein the error amplifier () is configured to control the voltage conversion module () based on the first and the second analog signals.

APD bias circuit with dual analog feedback loop control

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.

Signal switch and method of operating a signal switch

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.

Monitor device for a lighting arrangement, a driver using the monitoring arrangement, and a driving method

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.

Lighting unit and driving method

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.

Current modulation circuit, a driving circuit, and a method for driving a lighting load with current modulation

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.

Spatial dimming

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 (V) 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.

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Eindhoven, Netherlands

Aleksandar Sevo