Abstract:
The present invention relates to a data carrier (1) having a security mark (2) in which a code is embedded, which security mark is of an optical type. For instance, the mark is of the POWF (Physical One Way Functions) type which gives a speckle pattern for a specific light. From this speckle pattern it is possible to determine a code from which it is possible to get an authentication mark or a decrypting key. In an alternative, it is possible to use a hologram from which a key or authentication mark can be derived by using a unique spatial modulation filter at the level of the analysis of the security mark.
Abstract:
The invention relates to controlling a lighting device, particularly to the modulation of light generated by a solid state lighting (SSL) device. The invention provides a method and device for modulating the light emission of a lighting device by keying each pulse (14) of a sequence of pulses (16) contained in the control signal (10) according to a spreading code. Thus, the light emission of a lighting device may be identified by detecting the spreading code used for modulating the light emission. The invention is particularly suitable for lighting means containing several lighting devices such as a LED lighting board with dozens of LEDs since the light emission of each lighting device may be detected by the spreading code used for modulating the light emission.
Abstract:
A system (100) includes a first controllable light source (310) configured to provide a first light for illuminating a first location, and a second controllable light source (320) configured to provide a second light for illuminating a second location. A detector (330) is configured to receive the first light and measure first light attributes of the first light. A memory (140) is provided for storing a database that includes specification of the second controllable light source (320), and/or operating parameters of first controllable light source (310) for providing the first light. A processor (120) receives the first light attributes, and in conjunction with the specification of second controllable light source (320), controls the second light source (320) to provide the second light having second light attributes at the second location that substantially match the first light attributes of the first light illuminating the first location.