Electron gun for a color cathode ray tube
AssigneeSamsung Electron Devices Co., Ltd.
InventorTae-sik Oh
Life of this patent
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Abstract
An electron gun for a color cathode ray tube for realizing a high-quality image includes a triode having a cathode, a control electrode, and a screen electrode, and a main lens system having first to fourth focusing electrodes and an anode. The first focusing electrode and the fourth focusing electrode are electrically connected to each other, and the second focusing electrode and the third focusing electrode are electrically connected to the control electrode and the screen electrode, respectively. By forming a multistep auxiliary lens, the influence of spherical aberration and astigmatism on the electron beams are decreased and, in turn, a high-quality image can be realized.
Claims6
An electron gun for a color cathode ray tube comprising:
- a cathode for generating thermoelectrons;
- an adjacent control electrode and screen electrode for transforming said thermoelectrons into an electron beam;
- a first focusing electrode in the vicinity of said screen electrode, and a fourth focusing electrode electrically connected to said first focusing electrode;
- a second focusing electrode provided between said first and fourth focusing electrodes, and electrically connected to said control electrode;
- a third focusing electrode formed between said second and fourth focusing electrodes, and electrically connected to said screen electrode;
- and
- an anode adjacent said fourth focusing electrode.
An electron gun for a color cathode ray tube comprising:
- a prefocusing lens comprising a screen electrode and a first focusing electrode;
- an auxiliary lens comprising second, third and fourth focusing electrodes arranged sequentially, the first and fourth electrodes each having a first potential, the second electrode having a second potential and the third electrode having a third potential such that the first potential is greater than the second potential and the third potential is greater than the second potential;
- and
- a major lens comprising said fourth focusing electrode and an anode, the second focusing electrode being electrically connected to a control electrode and the third focusing electrode being electrically connected to the screen electrode so that a single virtual unipotential lens is formed between the first focusing electrode and the fourth focusing electrode which causes the electron beam to be focused and accelerated in multiple steps and which decrease the influence of spherical aberration and astigmatism on the electron beam.
Dependencies are inferred from the claim text.