Title:
CATHODE-RAY TUBE
Document Type and Number:
Japanese Patent JP2684996
Kind Code:
B2
Abstract:
PURPOSE: To provide a cathode-ray tube having an electron gun capable of solving at a stroke the problem concerning astigmatism due to deflection and the difference of focal lengths by relatively simple constitution.
CONSTITUTION: The former stage focusing electrode system, composed of at least a pair of first and second grid electrodes 23 and 24 arranged in order along an electron beam passage from a cathode side, is arranged between an acceleration electrode system and a latter stage focusing electrode system. A platelike projection 28 protruded from a one side grid electrode is provided on either one of the first and second grid electrodes so as to be across the electron beam passage in a nearly horizontal direction toward the other side grid electrode side facing to either of the two grid electrodes to make the opposite part to both the grid electrodes 23 and 24 have structure nonaxisymmetric to an electron beam shaft. Then constant focusing voltage Vfoc is applied to the other side grid electrode, and dynamic voltage Vfoc', gradually raised and lowered following the increase of beam deflection quantity with the constant focusing voltage Vfoc as a standard, is applied to one side grid electrode on which the platelike projection 28 is provided.
Inventors:
Kuniharu Nagakabe
Application Number:
JP19512194A
Publication Date:
December 03, 1997
Filing Date:
August 19, 1994
Export Citation:
Assignee:
株式会社日立製作所
International Classes:
H01J29/48; H01J29/50; (IPC1-7): H01J29/50
Domestic Patent References:
| JP54114175A | ||||
| JP5715463B2 | ||||
| JP607345B2 |
Attorney, Agent or Firm:
Ogawa Katsuo