US2982874A - Cathode-ray tube - Google Patents

Cathode-ray tube Download PDF

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Publication number
US2982874A
US2982874A US694299A US69429957A US2982874A US 2982874 A US2982874 A US 2982874A US 694299 A US694299 A US 694299A US 69429957 A US69429957 A US 69429957A US 2982874 A US2982874 A US 2982874A
Authority
US
United States
Prior art keywords
screen
wires
grids
cathode
ray tube
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US694299A
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English (en)
Inventor
Adriaan Gerard Van Doorn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Philips Corp
North American Philips Co Inc
Original Assignee
US Philips Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US2982874A publication Critical patent/US2982874A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/12—Picture reproducers
    • H04N9/16—Picture reproducers using cathode ray tubes
    • H04N9/22—Picture reproducers using cathode ray tubes using the same beam for more than one primary colour information
    • H04N9/26—Picture reproducers using cathode ray tubes using the same beam for more than one primary colour information using electron-optical colour selection means, e.g. line grid, deflection means in or near the gun or near the phosphor screen

Definitions

  • the said deviation can be compensated in the direction at right angles to the direction of the grid wires by arranging, in the case of a flat screen, the grid wires in a cylindrical plane in a manner such that the distance between grid and screen decreases towards the A compensation in the direction of length of the grid wires cannot be obtained in this manner, since it is practically impossible to have the taut grid wires curved.
  • the screen could, however, be made cylindrical, so that also in this direction the distance between grid and screen is smaller at the edges of the picture than in the centre.
  • the said difliculties are obviated in such a tube in that the grid wires are arranged in a cylindrical plane or surface and have a thickness which varies from the centre towards the edges.
  • the grid wires may thus be arranged in a cylindrical plane, of which the concave side faces the screen, while the wires themselves are thicker in the centre than at the ends. If, on the contrary, the screen is applied to the spherical window of the tube, the grid wires must lie in a cylindrical plane which is curved in the same direction as the screen, but which has a larger radius of curvature, while, in accordv by drawing them gradually upwards.
  • Such grids can be manufactured by immersing them, subsequent to winding of the wires, in the first-mentioned case, in an etching bath down to half their length and Thus the wires grow thinner towards the ends. Then the other half of the grids is treated in the same manner.
  • the grids are immersed first with one half and then with the other in a metal plating bath, in which metal is deposited on the wires. By withdrawing the grids slowly out of the bath, the wires canbe made thicker at the ends than in the centre; The decrease or increase in wire diameter may be linear or non-linear by controlling the rate of withdrawal of the grid wires and/orby means of the current intensity of the'bath.
  • Fig. 1 shows part of a cathode-ray tube having a flat screen
  • Fig. 2 shows part of such a tube, in which the screen is applied directly to the inner side of the window.
  • Fig, 3 is a cross-sectional view at right angles to that of Fig. 1.
  • Fig. 4 is a cross-sectional view at right angles to that of Fig. 2.
  • reference numeral 1 designates the bulb or envelope and 2 the window or faceplate of a cathode-ray tube.
  • the bulb contains a fiat glass plate 3, to which is applied the phosphor screen 4 consisting of different colour lines.
  • Close in front of the phosphor screen 4 are arranged the colour switching grids 5, of which the wires 6 are thicker in the centre than at the ends.
  • the grids 5 are curved cylindrically (as shown in Fig. 3) so that the hollow side faces the screen 4.
  • the grid wires may be made thinner by etching from the centre towards the ends.
  • the grid-screen unit is fastened in the bulb 1 in a manner not shown.
  • the phosphor screen 4 is applied directly to the window 2.
  • the grids 7 are curved cylindrically so that the hollow side is remote from the screen 4.
  • the grid wires 8 are thickened towards the ends by means of a metal-plating bath, so that the overcompensation of the deflection sensitivity, which is due to the fact that the distance between grids and screen required for the compensation inaccordance with Fig.
  • the grid wires may be immersed slowly into the bath and be drawn up rapidly or conversely. As an alternative, both the immersion and the withdrawal may be performed slowly.
  • the eflect in accordance with the invention may be obtained not only by variation in wire diameter, but also by flattening the wires partly in a manner such that the projection of the flattened wire portions on the screen is at a minimum at the areas where the wire diameter must be at a maximum. Then the flattened wire portions operate as narrow deflection plates.
  • the wire diameter or the width of the projection of the wires on the screen should vary between 50 and in order to ensure an adequate compensation of the deflection sensitivity.
  • a colored-image-producing cathode-ray tube comprising an electron-beam-producing gun, a beam-receiving screen having groups of lines of color phosphors, and beam-switching means disposed in front of the screen and comprising a pair of grids having substantially coplanar, interleaved wires and adapted to deflect the beam to impact a selected color line in accordance with varying potentials applied thereto, said interleaved wires lying in a generally cylindrically-curved surface whose axis extends parallel to the wires and said wires having varying diameters from their center toward their ends, whereby the deflection sensitivity of ,the beam-switching means is substantially uniform over the whole surfac of the grids.
  • a colored-image-producing cathode-ray tube comprising an electron-beam-producing gun, a substantiallyplanar beam-receiving screen having groups of lines of color phosphors,- and beam-switching means disposed in front. of the screen and comprising a pair of grids having substantially coplanar, interleaved wires and adapted to aesas'm 4.
  • a colored-image-producing cathode-ray tube comprising an electron-beam-producing gun, a curved beamreceiving screen having groups of lines of colorphosphors, and beam-switching meansdisposed in front of the screen and comprising a pair of grids having substantially coplanar, interleaved wires and adapted to deflect the beam to impact a selected color line in accordance with varying potentials applied'th'ereto, said interleaved wires lying in a cylindrical surface whose axis extends parallel tothe wires and on the side of the wires opposite to that of the'screen so that the convex side of the surface faces the curved screen, said cylindrical surface having a smaller curvature than the screen, said wires. each having a diameter that is larger at both ends substantially uniform over the whole surface of the grids.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Electrodes For Cathode-Ray Tubes (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
US694299A 1956-11-15 1957-11-04 Cathode-ray tube Expired - Lifetime US2982874A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL362116X 1956-11-15

Publications (1)

Publication Number Publication Date
US2982874A true US2982874A (en) 1961-05-02

Family

ID=19785420

Family Applications (1)

Application Number Title Priority Date Filing Date
US694299A Expired - Lifetime US2982874A (en) 1956-11-15 1957-11-04 Cathode-ray tube

Country Status (7)

Country Link
US (1) US2982874A (cs)
BE (1) BE562350A (cs)
CH (1) CH362116A (cs)
DE (1) DE1039094B (cs)
FR (1) FR1186038A (cs)
GB (1) GB864796A (cs)
NL (1) NL212215A (cs)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3440469A (en) * 1966-09-01 1969-04-22 Georges Bradu Flat screen attachment inside cathoderay tube by snap ring and clip assembly

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1542386A (en) * 1920-12-14 1925-06-16 Western Electric Co Vacuum-tube design
US2075202A (en) * 1934-12-12 1937-03-30 Philips Nv Electron discharge tube
US2640767A (en) * 1951-02-12 1953-06-02 Dow Chemical Co Etching
US2653263A (en) * 1952-01-08 1953-09-22 Chromatic Television Lab Inc Color control grid structure for cathode-ray tubes
US2722623A (en) * 1953-03-31 1955-11-01 Rca Corp Color-kinescopes etc.
US2729760A (en) * 1953-03-17 1956-01-03 Chromatic Television Lab Inc Electrode structure for cathode-ray tubes for image production in natural color
US2746848A (en) * 1955-01-19 1956-05-22 Photo Engravers Res Inc Etching
US2795720A (en) * 1955-09-15 1957-06-11 Rca Corp Post-accelerated color-kinescopes
US2813213A (en) * 1954-11-03 1957-11-12 Avco Mfg Corp Color cathode-ray tube and assembly process

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1542386A (en) * 1920-12-14 1925-06-16 Western Electric Co Vacuum-tube design
US2075202A (en) * 1934-12-12 1937-03-30 Philips Nv Electron discharge tube
US2640767A (en) * 1951-02-12 1953-06-02 Dow Chemical Co Etching
US2653263A (en) * 1952-01-08 1953-09-22 Chromatic Television Lab Inc Color control grid structure for cathode-ray tubes
US2729760A (en) * 1953-03-17 1956-01-03 Chromatic Television Lab Inc Electrode structure for cathode-ray tubes for image production in natural color
US2722623A (en) * 1953-03-31 1955-11-01 Rca Corp Color-kinescopes etc.
US2813213A (en) * 1954-11-03 1957-11-12 Avco Mfg Corp Color cathode-ray tube and assembly process
US2746848A (en) * 1955-01-19 1956-05-22 Photo Engravers Res Inc Etching
US2795720A (en) * 1955-09-15 1957-06-11 Rca Corp Post-accelerated color-kinescopes

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3440469A (en) * 1966-09-01 1969-04-22 Georges Bradu Flat screen attachment inside cathoderay tube by snap ring and clip assembly

Also Published As

Publication number Publication date
GB864796A (en) 1961-04-06
NL212215A (cs)
BE562350A (cs)
DE1039094B (de) 1958-09-18
FR1186038A (fr) 1959-08-12
CH362116A (de) 1962-05-31

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