公开(公告)号：DE69921616T2

公开(公告)日：2005-09-15

申请号：DE69921616

申请日：1999-12-02

Applicant: PHILIPS INTELLECTUAL PROPERTY

Inventor： DERRA H ,  FISCHER E ,  GANSER G ,  KRUECKEN THOMAS ,  MOENCH HOLGER ,  SNIJKERS ROB

IPC: H05B41/24 ,  H05B41/282 ,  H05B41/292

Abstract: The invention is concerned with a circuit arrangement for operating a high pressure discharge lamp comprising input terminals (K1, K2) for connection to a supply voltage source, output terminals for connecting the high pressure discharge lamp, and means, coupled to the input terminals, for supplying an alternating lamp current to the high pressure discharge lamp. The lamp current has per period a mean value Im. According to the invention the lamp current in each period at its start is lowered with respect to the mean value Im so as to allow for stable diffuse attachment on the cathodic phase electrode. The circuit arrangement is in particular suited for operating a lamp in an optical projection system

公开(公告)号：DE69921616D1

公开(公告)日：2004-12-09

申请号：DE69921616

申请日：1999-12-02

Applicant: KONINKL PHILIPS ELECTRONICS NV ,  PHILIPS INTELLECTUAL PROPERTY

Inventor： DERRA H ,  FISCHER E ,  GANSER G ,  KRUECKEN THOMAS ,  MOENCH HOLGER ,  SNIJKERS ROB

IPC: H05B41/24 ,  H05B41/282 ,  H05B41/292

Abstract: The invention is concerned with a circuit arrangement for operating a high pressure discharge lamp comprising input terminals (K1, K2) for connection to a supply voltage source, output terminals for connecting the high pressure discharge lamp, and means, coupled to the input terminals, for supplying an alternating lamp current to the high pressure discharge lamp. The lamp current has per period a mean value Im. According to the invention the lamp current in each period at its start is lowered with respect to the mean value Im so as to allow for stable diffuse attachment on the cathodic phase electrode. The circuit arrangement is in particular suited for operating a lamp in an optical projection system

公开(公告)号：DE69912102T2

公开(公告)日：2004-07-29

申请号：DE69912102

申请日：1999-12-01

Applicant: KONINKL PHILIPS ELECTRONICS NV ,  PHILIPS INTELLECTUAL PROPERTY

Inventor： DERRA H ,  FISCHER E ,  GANSER G ,  KRUCKEN THOMAS ,  MOENCH HOLGER ,  SNIJKERS ROB

IPC: H05B41/282 ,  H05B41/16 ,  H05B41/292

Abstract: A circuit arrangement is provided for operating a high pressure discharge lamp with a lamp current which, in successive periods, has opposite polarities. The lamp is provided with at least two main electrodes being spaced an electrode distance from each other. The circuit arrangement includes input terminals for connection to a supply source, output terminals for connection to the high pressure discharge lamp, and an element, coupled to the input terminals, for supplying the lamp current to the high pressure discharge lamp, which current, in successive periods, has a predetermined shape. The circuit arrangement is provided with an element for detecting a first parameter indicative of the electrode distance and forming a first signal dependent on the first parameter and with an element for reshaping the lamp current, in successive periods, in dependence of the thus formed first signal.

公开(公告)号：DE69912102D1

公开(公告)日：2003-11-20

申请号：DE69912102

申请日：1999-12-01

Applicant: KONINKL PHILIPS ELECTRONICS NV ,  PHILIPS INTELLECTUAL PROPERTY

Inventor： DERRA H ,  FISCHER E ,  GANSER G ,  KRUCKEN THOMAS ,  MOENCH HOLGER ,  SNIJKERS ROB

IPC: H05B41/282 ,  H05B41/16 ,  H05B41/292

Abstract: A circuit arrangement is provided for operating a high pressure discharge lamp with a lamp current which, in successive periods, has opposite polarities. The lamp is provided with at least two main electrodes being spaced an electrode distance from each other. The circuit arrangement includes input terminals for connection to a supply source, output terminals for connection to the high pressure discharge lamp, and an element, coupled to the input terminals, for supplying the lamp current to the high pressure discharge lamp, which current, in successive periods, has a predetermined shape. The circuit arrangement is provided with an element for detecting a first parameter indicative of the electrode distance and forming a first signal dependent on the first parameter and with an element for reshaping the lamp current, in successive periods, in dependence of the thus formed first signal.