Electric circuit arrangements incorporating cathode ray tubes
Electron gun for projection television cathode ray tubes
Unipotential electron gun for short cathode ray tubes Patent #: 4496877
ApplicationNo. 06/544169 filed on 10/21/1983
US Classes:315/15, Three or more stages313/414, With focusing and accelerating electrodes313/449With additional electrode
ExaminersPrimary: Blum, Theodore M.
Attorney, Agent or Firm
International ClassesH01J 29/58 (20060101)
H01J 29/62 (20060101)
Foreign Application Priority Data1982-10-29 NL
AbstractThe spot quality of an electron beam produced by an electron gun in a cathode ray tube is improved by optimizing the dimensions of a beam-forming, apertured electrode arrangement in the gun. This arrangement includes electrodes for forming a cross-over followed by, in the direction of propagation of the electron beam, first and second lens electrodes centered around an axis, for defining an accelerating and prefocusing lens and at least two lens electrodes for defining a main focusing lens. The diameter of the aperture in the second lens electrode is smaller than twice the diameter of the aperture in the first lens electrode, and the effective spacing S-eff between the first and the second lens electrodes is smaller than 1 mm. S-eff is defined as the minimum of the function ##EQU1## where ƊV is the operating voltage difference between the second and first lens electrodes andE(z) is the operating electrical field strength between the first and second lens electrodes on the beam (z) axis as a function of the place z on the axis.