Projection system e.g. for digital light processing system, has high pressure discharge lamp controlled by alternating current input with over increase of light current is achievable

摘要

The system has a high pressure discharge lamp (10) controlled by alternating current input. An over increase of the light current is achievable via a current pulse which is added to the alternating current. A grey filter (30d) is provided which is synchronously integrated to the over increase of the light current and induced by the current impulse into path of rays of the discharge lamp.