Abstract: The present invention relates to a picture display device having a cathode ray tube (2), control means (50) for controlling the electron beam/beams of the cathode ray tube (2), an indexing element (12, 14) for determining whether the electron beam/beams impinges at the correct location, and a feedback system for providing the control means (50) with a signal generated by the indexing means (12,14). The feedback system comprises a level shifter (30) for transferring the signal from a high-voltage system (20) of the cathode ray tube and the indexing elements (12, 14) to a low-voltage system (22) of the control means (50). In order to provide the level shifter (30) with the capacity of transferring signals comprising high frequencies, the level shifter (30) is provided with an input stage (32a, 32b) arranged to decrease the input impedance of the level shifter (30).
Type:
Application
Filed:
December 20, 2001
Publication date:
September 5, 2002
Inventors:
Petrus Johannes Gerardus Van Lieshout, Pieter Johannes Engelaar
Abstract: In a magnetron for microwave oven, a high-voltage input terminal structure 30 is provided on a shield box 26 mounted on a magnetron unit 22. The high-voltage input terminal structure 30 has a cylindrical earth electrode 33, a cylindrical high potential inner electrode 32 and a central conductor 31a. The cylindrical earth electrode 33 is secured to the shield box 26 and the cylindrical high potential inner electrode 32 is coaxially arranged in the cylindrical earth electrode 33. The central conductor 31a is connected through an inductor 28 to a cathode lead 27 of the magnetron unit 22. An insulating resin 34b is filled in a gap between the cylindrical earth electrode 33 and the highpotential electrode 32 to form a capacitor section C. Cylindrical insulating sheaths 37, 38 are formed by the resin on the both sides of the capacitor section C. The capacitor section C and the cylindrical insulating sheaths, 37, 38 are integrally formed and continuously extended along a straight line.