A lighting device (30) having a housing (12) which includes a lamp means, a battery housing to receive at least one battery and a switch means to open and close a circuit between said lamp means and terminals of said at least one battery when located in said housing. Said lighting device includes a lanyard (110, 112) attached to said housing (12) characterised by said lanyard having a proximal end attached to said housing (12) and a distal end, whereby said distal end or a portion of said lanyard (110, 112) is adapted to be releasably attached to said housing (12).

An LED lighting device is provided which is capable of being connected to a network and being controlled by a host computer also connected to the network. The lighting device has several lifespan expanding features such as including several extra LEDs such that as the LEDs of the lighting device degrade over time more LEDs can be turned on thus allowing a constant luminosity to be maintained.

Illumination device for a vehicle comprises a first lamp module (30) and a second lamp module (40), each having a number of light-emitting diodes (31, 41). The second lamp module surrounds the first lamp module. The lamp modules are staggered in relation to each other and are separately fixed so that they can be individually replaced. Preferred Features: The second lamp module is optically set back behind the first lamp module.

A reflector lamp is described which consist essentially of a light source, in particular in the form of a high-pressure gas discharge lamp (HID [high intensity discharge] lamp or UHP [ultra high performance] lamp), as well as a main or secondary reflector ( 12 ), and a primary reflector ( 25 ) by means of which light from the light source ( 22 ) can be reflected through the light source ( 22 ) onto the main reflector ( 12 ). The primary reflector ( 25 ) is arranged such that those regions of the main reflector ( 12 ) are obscured which are optically inactivated regions, for example because of a lead-through and/or a fastening device for the lamp, which have no reflection properties, or which have reflection properties that adversely affect the radiation characteristic of the reflector lamp. The reflector lamp is particularly suitable for projection applications because of its high luminous efficacy. Furthermore, a substantially automated and accordingly cost-effective assembly of the lamp is possible.

A method of fabricating light-sensing devices including photodiodes monolithically integrated with CMOS devices. Several types of photodiode devices (PIN, HIP) are expitaxially grown in one single step on active areas implanted in a common semiconductor substrate, the active areas having defined polarities. The expitaxially grown layers for the photodiode devices may be either undoped or in-situ doped with profiles suitable for their respective operation. With appropriate choice of substrate materials, device layers and heterojunction engineering and process architecture, it is possible to fabricate silicon-based and germanium-based multi-spectral sensors that can deliver pixel density and cost of fabrication comparable to the state of the art CCDs and CMOS image sensors. The method can be implemented with epitaxially deposited films on the following substrates: Silicon Bulk, Thick-Film and Thin-Film Silicon-On-Insulator (SOI), Germanium Bulk, Thick-Film and Thin-Film Geranium-On-Insulator (GeOI).

A vehicle headlight is described with a reflector housing ( 1, 21 ) and a front glass ( 22 ) which together enclose a headlight inner space. The headlight has a reference surface ( 15, 35 ) for defining the position of a lamp ( 7, 30 ) having a lamp body ( 8, 31 ) and a lamp base ( 9, 37 ) in the headlight The headlight is constructed such that the lamp ( 7, 30 ) can be inserted such that the lamp base ( 9, 37 ) is positioned in front of the lamp body ( 8, 31 ), viewed against the direction of radiation of the headlight In addition, a lamp ( 7, 30 ) is described which is constructed such that it can be inserted into the vehicle headlight in the manner described.

A method to control the illumination intensity of a gas discharge lamp is achieved. The method comprises, first, converting an analog lamp illumination signal into a digital lamp illumination signal. The analog lamp illumination signal is a function of the illumination intensity of a gas discharge lamp. Second, digital target signal is subtracted from the digital lamp illumination signal to create a digital error signal. Third, a digital frequency set point is adjusted from a current value to a new value based on the digital error signal. The digital frequency set point is a high resolution digital value. Fourth, the current value and the new value are averaged by a digital delta sigma modulator to create a smoothed frequency set point. The smoothed frequency set point is a medium resolution value. Finally, an oscillating voltage signal is generated with a drive frequency based on the smoothed frequency set point. The drive frequency determines the illumination intensity of the gas discharge lamp.

The invention proposes a technique for measuring chromatic dispersion in an optical communication line transmitting an optical signal at a predetermined optical wavelength. The technique comprises determining the sign of chromatic dispersion and includes introducing controlled changes of wavelength around the predetermined wavelength, monitoring the optical signal that has passed said line, and obtaining a first and a second signals, wherein the first signal reflects changes of the carrier wavelength, and the second signal reflects changes of delay of the optical signal transmitted via the line. The two signals are compared and the chromatic dispersion sign is determined based on the phase difference there-between.