# US 5,708,322 A · Color cathode ray tube with in-line electron gun > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,322 A - Document ID: US5708322A - Status: Granted - Kind: A - Application number: 08/685,005 - Filed: 1996-07-22 - Granted: 1998-01-13 - Earliest claimed: 1993-04-21 - Assignees: Hitachi, Ltd. - Inventors: Go Uchida; Syoji Shirai - Web page: https://patentgrep.com/patent/US5708322A ## CPC - H01J 29/503: {Three or more guns, the axes of which lay in a common plane} - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A color cathode ray tube equipped with an in-line electron gun emitting three electron beams includes a main lens made up of two cylindrical electrodes arranged in a spaced relationship. Each of the electrodes has an opening of an elliptic cross section and therein a plate electrode with a beam passing area, and is given different voltages. The following inequalities apply: 5.0>S, D>S, and 55S-20D.gtoreq.145.5, S is a beam spacing between adjacent electron beams, and D is the smaller dimension of either a diameter in a direction perpendicular to the in-line arrangement of three electron beams of the cross section of the opposing ends of the two cylindrical electrodes or twice the distance between a center of a side electron beam and an inner edge in a direction of the in-line arrangement of the three electron beams of the cross section of the opposing edge of the two cylindrical electrodes. ## Claims ### Claim 1 A color cathode ray tube equipped with an in-line electron gun comprising three cathodes for emitting three electron beams of in-line arrangement toward a fluorescent screen, and a main lens for focusing said three electron beams on the fluorescent screen, said main lens comprising two cylindrical electrodes arranged in a spaced relationship in a direction of an axis of said tube, each having an opening and having therein a plate electrode with a beam passing area, said two cylindrical electrodes being given different voltages, wherein the D and S values are in the region where all of the following inequalities are satisfied; S<5.0, S<D, and 145.5.ltoreq.55S-20D S being a beam spacing in mm between central axes of said three adjacent electron beams, and D being the smaller dimension in mm of one of (a) a diameter in mm in a direction perpendicular to an in-line arrangement of said three electron beams of said cross section of an opening at opposing ends of said two cylindrical electrodes and (b) a distance in mm related to a spacing between a center of a side electron beam and a nearer inner edge of said two cylindrical electrodes in a direction of said in-line arrangement of said three electron beams of said cross section of the opening at opposing ends of said two cylindrical electrodes. ### Claim 2 (depends on 1) A color cathode ray tube according to claim 1, wherein each of said opposing ends of said two cylindrical electrodes comprises a common single opening for said three electron beams. ### Claim 3 (depends on 1) A color cathode ray tube according to claim 1, wherein an outside diameter of a neck portion of a vacuum envelope accommodating said in-line electron gun is less than 28.1 mm. ### Claim 4 (depends on 1) A color cathode ray tube according to claim 1, wherein an outside diameter of a neck portion of a vacuum envelope accommodating said in-line electron gun is less than 26.7 mm. ### Claim 5 (depends on 1) A color cathode ray tube according to claim 1, wherein an outside diameter of a neck portion of a vacuum envelope accommodating said in-line electron gun is less than 25.3 mm. ### Claim 6 (depends on 1) A color cathode ray tube according to claim 1, wherein said plate electrode has a thickness in mm which extends in a direction of an axis of said tube. ### Claim 7 (depends on 1) A color cathode ray tube according to claim 1, wherein the following inequalities are satisfied, 2S+14.6.ltoreq.T.ltoreq.28.1 4.1.ltoreq.S, T being an outside diameter in mm of a neck portion of a vacuum envelope housing said in-line electron gun. ### Claim 8 (depends on 1) A color cathode ray tube according to claim 1, wherein the following inequalities are satisfied, 2S+14.6.ltoreq.T<26.7 4.1.ltoreq.S, T being an outside diameter in mm of a neck portion of a vacuum envelope housing said in-line electron gun. ### Claim 9 (depends on 1) A color cathode ray tube according to claim 1, wherein the following inequalities are satisfied, 2S+14.6.ltoreq.T.ltoreq.25.3 4.1.ltoreq.S, T being an outside diameter in mm of a neck portion of a vacuum envelope housing said in-line electron gun. ### Claim 10 (depends on 1) A color cathode ray tube according to claim 1, wherein said plate electrode has a thickness which is substantially smaller than the radius of said beam passing area in a direction parallel to said in-line arrangement of said three electron beams. ### Claim 11 (depends on 1) A color cathode ray tube according to claim 1, wherein (b) the distance in mm related to a spacing between a center of a side electron beam and a nearer inner edge of said two cylindrical electrodes in a direction of said in-line arrangement of said three electron beams for the dimension D is twice the spacing in mm between the center of the side electron beam and the nearer inner edge of said two cylindrical electrodes in the direction of said in-line arrangement of said three electron beams of said cross section of said opening at opposing ends of said two cylindrical electrodes.