Koninklijke Philips Corporation N.v.

Wouter Jozef Maes

Jens Pollmann-Retsch

Edmond Mariette Emile Verstraeten

Holger Joachim Moench

Holger Mönch

Mads Glavind

Jan Alfons Julia Stoffels

Edmond Mariette E Verstraeten

A lighting unit is described which has a discharge lamp (), in particular a high pressure or high intensity discharge (HID) lamp or an ultra high performance (UHP) lamp, a lamp driver () and a cooling device (). To reduce mechanical stresses caused by temperature variations in the lamp (), one or more operating parameters of the lamp () are detected. In addition, a control unit is provided for controlling the lamp driver () and/or the cooling device () at least during switching on and/or off of the lighting unit in such a way that there is no excursion from a predetermined range of the at least one operating parameter. By selecting the parameter range suitably, the service life of the lamp may be extended considerably or the power of the lamp may be increased while the service life remains the same.

Lighting unit

A moving-head device () comprises afoot () and ahead () that is movably arranged with respect to the foot (). The head () comprises a first rotation member () that is rotatable with respect to the foot () about a first rotation axis (), and a second rotation member () that is rotatable with respect to the first rotation member () about a second rotation axis (). A lamp () is arranged inside the first rotation member (), while directing means () are provided for directing light originating from the lamp () to an external light outlet (). If the first rotation axis () extends in a vertical portion of the lamp () constituting an upper side () does not change during operation of the moving-head device (), so that said portion may be easily cooled continuously.

Moving-head device comprising a lamp

A discharge lamp, and particularly a high-pressure gas-discharge lamp (an HID (high-intensity discharge) lamp or UHP (ultra-high performance) lamp), having a reflector and a cooling means is described. The cooling means comprises at least one nozzle () by which a flow of gas can be directed onto the discharge lamp, the at least one nozzle () being so arranged that it does not extend, at least to any substantial degree, into a beam path produced by the lamp () and the reflector (). In this way, the cooling means does not produce any obstacles on the beam path for the light. With preferred embodiments, it is possible to produce a turbulent flow that surrounds particularly the discharge vessel () of the lamp and that considerably increases the effectiveness of the cooling means. Further embodiments also allow the discharge lamp to be operated in a plurality of different positions without individual regions of the lamp being too little or too severely cooled.

Discharge lamp having cooling means

A cooling unit () having a pump () for generating an airflow is provided for cooling a High Power lamp () during operation. The value of the airflow is controlled by a control unit () which comprises a driver () for determining a required value of the airflow on the basis of the operating power of the lamp (). The control unit () comprises two pressure sensors () for measuring a pressure of the airflow as well as a pressure drop of the airflow across an orifice (). The driver () is designed for processing the measuring results in order to determine an actual value of the airflow. The value of the airflow is accurately controlled by adjustment of the power supply to the pump () in order to obtain a match of the actual value of the airflow and the required value of the airflow.

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Zwijndrecht, Belgium

Wouter Jozef Maes