<p>The display apparatus comprises a picture tube (CRT) with an electron gun which generates an electron beam (EB) directed towards a display screen. The electron gun comprises a first and a second electrode (CA, G1). The electron beam (EB) originates from the first electrode (CA). The voltage between the first electrode (CA) and the second electrode (G1) controls the intensity of the electron beam (EB). A beam current (IB) flows in the first electrode (CA) in response to the electron beam (EB). A total current (ICA) in the first electrode (CA) is the sum of the beam current (IB) and a current (IC) flowing through a capacitance (CIN) between the first and the second electrode (CA, G1). A compensation circuit (COM) supplies a compensation current (ICO) to the first electrode (CA) to compensate for a capacitive current (IC) through a capacitance (CIN) between the first and the second electrode (CA, G1). A beam current measurement circuit (BMC) measures the total current (IT) which is the sum of the total current in the first electrode (ICA) and the compensation current (ICO).</p>
申请公布号
WO2004028145(A1)
申请公布日期
2004.04.01
申请号
WO2003IB03623
申请日期
2003.08.08
申请人
KONINKLIJKE PHILIPS ELECTRONICS N.V.;CORTENRAAD, HUBERTUS, M., R.;VAN DEN BIGGELAAR, PETER
发明人
CORTENRAAD, HUBERTUS, M., R.;VAN DEN BIGGELAAR, PETER