ELECTRON GUN OF CATHODE RAY TUBE FOR IMPROVING SPOT SHAPE AT EDGE OF SCREEN OF HD TELEVISION

摘要

PURPOSE: An electron gun of a cathode ray tube is provided to improve the spot shape at the edge of the screen of an HD(High Definition) television and increase the horizontal size of electron beam in a main lens of the electron gun. CONSTITUTION: An electron gun of a cathode ray tube includes an electron-emitting cathode(K), the first and second electrodes(G1,G2), an electronic lens(G4), the first and second four-polarity devices, and a main electronic lens. The first and second electrodes form electron beams and focus the electron beams on a crossover point. The electronic lens previously focuses the electron beams. The first four-polarity device is dynamically controlled in synchronization with screen scanning such that a beam focusing error is corrected at the edge of a screen. The main electronic lens focuses the electron beams on the screen. The second four-polarity device is located between the electronic lens and the first four-polarity device.