US2500623A - Cathode-ray device - Google Patents

Cathode-ray device Download PDF

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Publication number
US2500623A
US2500623A US730719A US73071947A US2500623A US 2500623 A US2500623 A US 2500623A US 730719 A US730719 A US 730719A US 73071947 A US73071947 A US 73071947A US 2500623 A US2500623 A US 2500623A
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magnetic
gun
cathode ray
focussing
axis
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Expired - Lifetime
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US730719A
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Cyrus H Babbs
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Pye Electronic Products Ltd
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Pye Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/56—Arrangements for controlling cross-section of ray or beam; Arrangements for correcting aberration of beam, e.g. due to lenses

Definitions

  • the present invention relates to cathode ray devices, such as cathode ray tubes, monoscopes and electron pickup tubes as used in television, in ywhich the cathode ray beam is focussed and deflected by electromagnetic means, such as by coils disposed around theI neck ofthe tube.
  • the-deiiecting coils and/or the 'gcathode ray gun may introduce astigmatism by distorting the electron beam
  • the present invention has for its object to provide additional means which introduce astigmatism of the cathode ray beam to compensate for the astigmatism produced by the deflecting coils and/or the cathode ray gun.
  • two magnetic members are disposed at diametrcally opposite positions with respect to the axis of the cathode ray gun and between the focussing coil and the gun.
  • the magnetic members are carried by a non-magnetic framework or ring which is adjustable both rotatably and longitudinally.
  • Fig. 1 shows a plan View, partly cut away, of a cathode ray tube incorporating the compensating device according to this invention.
  • Fig. 2 shows a perspective view of the compensating device.
  • the neck portion of the cathode ray tube I having the electron gun 2 disposed at its end is surrounded by the focussing coil 3 and deflecting coils 4 in known manner.
  • two soft iron pins 5 and 6 are supported at diametrically opposite points of the neck of the tube and between the focussing coil 3 and the gun 2 by means of a ring 1 of non-magnetic material.
  • the ring 1 is constructed in the form of a tubular member which is provided with a longitudinal slit 8 to impart slight resiliency to this member and allow it to bear with friction upon the outer surface of the neck portion of the cathode ray tube.
  • a collar 8 which preferably has a knurled peripheral edge, by means of which the tubular member and the two soft iron pins carried thereby can be adjusted longitudinally along the neck of the tube and rotatably therearound.
  • the iron pins 5 and 6 are disposed with their axes extending in the direction of the 1ongitudinal axis of the tube.
  • astigmatism By adjusting the position of the iron pins, both longitudinally and rotatably with respect to the focussing coil, astigmatism can be introduced 6 Claims. (Cl. Z50-157) into the focussing which is such that it compensates vfor the astigmatism caused by deflecting coil de-focussing and/or by the cathode ray gun.
  • the compensating device is adjusted with the 'scanning voltages applied on the deflecting coils to produce the sharpest definition of the electron beam;
  • a cathode ray device comprising an evacuated envelope having a neck portion containing an electron gun, magnetic focussing means and electro-magnetic deflecting coils surrounding said neck portion, a non-magnetic member adjustable longitudinally with respect to the axis of the gun, two magnetisable members mounted on said non-magnetic member in diametrically opposed portions with respect to the axis of the gun, said magnetisable members being disposed in the magnetic field of the focussing means for magnetisas tion thereby.
  • a cathode ray device comprising an evacuated envelope having a neck portion containing an electron gun, magnetic focussing means and electro-magnetic deflecting coils surrounding said neck portion, a non-magnetic member adjustable both rotatably and longitudinally with respect to the axis of the gun, two magnetisable members mounted on said non-magnetic member in diametrically opposed positions with respect to the axis of the gun, said magnetisable members being disposed in the magnetic eld of the focussing mea-ns for magnetisation thereby.
  • a cathode ray device comprising an evacuated envelope having a neck portion containing an electron gun, magnetic focussing means and electro-magnetic deflecting coils surrounding said neck portion, a non-magnetic member adjustable longitudinally with respect to the axis of the gun, two soft iron pins disposed with their axes extending in the'direction of the axis of the gun mounted on said non-magnetic member in diametrically opposed positions with respect to the axis of the gun, said soft iron pins being disposed in the magnetic field of the focussing means for magnetisation thereby.
  • a cathode ray device comprising an evacuated envelope having a neck portion containing an electron gun, magnetic focussing means and electro-magnetic deflecting coils surrounding said neck portion, a split tubular member of non- 3 magnetic iaterial adjustable at least longitudinally with respectI to the axis of the gun, tWo soft iron pins disposed with their axes extending in the direction of the axis of the gun mounted on said non-magnetic member in diametrically opposed positions with respect to the axis of the gun, said magnetisable members rbeing disposed in the magnetic field of the focussing means vfor magnetisation thereby, the intensity of magnetisation being adjustable by longitudinal movement of the non-magnetic member relatively to the focussing means.
  • a cathode ray device comprising an evacuated envelope having a neck ,portion containing an electron gun, magnetic focussing means and electro-magnetic deecting coils surrounding said neck portion, a split tubular member of non-magnetic material having a collar to facilitate-manual adjustment of the non-magnetic member .bothrotatably and longitudinally with respect to the axis of the gun, two soft iron pins disposed with their axes extending in the direction of the ⁇ axis of the gun mounted on said non-magnetic member .in diametrically opposed positions with respect to lthe axis of the gun, said magnetisable members being disposed in the magnetic field of the focussing means for magnetisation thereby, the intensity of magnetisation being adjustable bylongitudinalmovement of the non-magnetic member relatively to the focussing means.
  • a cathode ray device comprising an eifachw uated envelope having a neck portion containing an electron gun, an electro-magnetic focussing l.focussing coil to adjust the intensity of mag- 'netsation of the pins by the magnetic field of the .focussing coil, said carrying member also being .rotatable with the respect to the axis of the gun,

Description

March 14, 1950 c. H. BABBs CATHODE RAY DEVICE Filed Feb. 25. 1947 Mmm 'Inventor Hevber Bcl bbs. @wwwa/3A;
@TUS
Allorney Patented Mar. 14, 1950 y "I Pye Limited, Ca f company "bridge, England, a British Application February 25, 1947, Serial No. 730,719
In Great Britain Marchk 2, 1946 The present invention relates to cathode ray devices, such as cathode ray tubes, monoscopes and electron pickup tubes as used in television, in ywhich the cathode ray beam is focussed and deflected by electromagnetic means, such as by coils disposed around theI neck ofthe tube.
In such devicesthe-deiiecting coils and/or the 'gcathode ray gun may introduce astigmatism by distorting the electron beam, and the present invention has for its object to provide additional means which introduce astigmatism of the cathode ray beam to compensate for the astigmatism produced by the deflecting coils and/or the cathode ray gun.
According to the present invention, two magnetic members are disposed at diametrcally opposite positions with respect to the axis of the cathode ray gun and between the focussing coil and the gun. The magnetic members are carried by a non-magnetic framework or ring which is adjustable both rotatably and longitudinally.
In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings, in which:
Fig. 1 shows a plan View, partly cut away, of a cathode ray tube incorporating the compensating device according to this invention.
Fig. 2 shows a perspective view of the compensating device.
Referring to the drawings, the neck portion of the cathode ray tube I having the electron gun 2 disposed at its end is surrounded by the focussing coil 3 and deflecting coils 4 in known manner. According to the invention two soft iron pins 5 and 6 are supported at diametrically opposite points of the neck of the tube and between the focussing coil 3 and the gun 2 by means of a ring 1 of non-magnetic material. In the embodiment shown the ring 1 is constructed in the form of a tubular member which is provided with a longitudinal slit 8 to impart slight resiliency to this member and allow it to bear with friction upon the outer surface of the neck portion of the cathode ray tube. At the end of the tubular member 'l is provided a collar 8, which preferably has a knurled peripheral edge, by means of which the tubular member and the two soft iron pins carried thereby can be adjusted longitudinally along the neck of the tube and rotatably therearound. The iron pins 5 and 6 are disposed with their axes extending in the direction of the 1ongitudinal axis of the tube.
By adjusting the position of the iron pins, both longitudinally and rotatably with respect to the focussing coil, astigmatism can be introduced 6 Claims. (Cl. Z50-157) into the focussing which is such that it compensates vfor the astigmatism caused by deflecting coil de-focussing and/or by the cathode ray gun. The compensating device is adjusted with the 'scanning voltages applied on the deflecting coils to produce the sharpest definition of the electron beam;
Whilst a particular embodiment has been described, it will be understood that various modications may be made without departing from the scope of the invention as defined by the appended claims.
I claim:
1. A cathode ray device comprising an evacuated envelope having a neck portion containing an electron gun, magnetic focussing means and electro-magnetic deflecting coils surrounding said neck portion, a non-magnetic member adjustable longitudinally with respect to the axis of the gun, two magnetisable members mounted on said non-magnetic member in diametrically opposed portions with respect to the axis of the gun, said magnetisable members being disposed in the magnetic field of the focussing means for magnetisas tion thereby.
2. A cathode ray device comprising an evacuated envelope having a neck portion containing an electron gun, magnetic focussing means and electro-magnetic deflecting coils surrounding said neck portion, a non-magnetic member adjustable both rotatably and longitudinally with respect to the axis of the gun, two magnetisable members mounted on said non-magnetic member in diametrically opposed positions with respect to the axis of the gun, said magnetisable members being disposed in the magnetic eld of the focussing mea-ns for magnetisation thereby.
3. A cathode ray device comprising an evacuated envelope having a neck portion containing an electron gun, magnetic focussing means and electro-magnetic deflecting coils surrounding said neck portion, a non-magnetic member adjustable longitudinally with respect to the axis of the gun, two soft iron pins disposed with their axes extending in the'direction of the axis of the gun mounted on said non-magnetic member in diametrically opposed positions with respect to the axis of the gun, said soft iron pins being disposed in the magnetic field of the focussing means for magnetisation thereby.
4. A cathode ray device comprising an evacuated envelope having a neck portion containing an electron gun, magnetic focussing means and electro-magnetic deflecting coils surrounding said neck portion, a split tubular member of non- 3 magnetic iaterial adjustable at least longitudinally with respectI to the axis of the gun, tWo soft iron pins disposed with their axes extending in the direction of the axis of the gun mounted on said non-magnetic member in diametrically opposed positions with respect to the axis of the gun, said magnetisable members rbeing disposed in the magnetic field of the focussing means vfor magnetisation thereby, the intensity of magnetisation being adjustable by longitudinal movement of the non-magnetic member relatively to the focussing means.
5. A cathode ray device comprising an evacuated envelope having a neck ,portion containing an electron gun, magnetic focussing means and electro-magnetic deecting coils surrounding said neck portion, a split tubular member of non-magnetic material having a collar to facilitate-manual adjustment of the non-magnetic member .bothrotatably and longitudinally with respect to the axis of the gun, two soft iron pins disposed with their axes extending in the direction of the `axis of the gun mounted on said non-magnetic member .in diametrically opposed positions with respect to lthe axis of the gun, said magnetisable members being disposed in the magnetic field of the focussing means for magnetisation thereby, the intensity of magnetisation being adjustable bylongitudinalmovement of the non-magnetic member relatively to the focussing means.
6. A cathode ray device comprising an eifachw uated envelope having a neck portion containing an electron gun, an electro-magnetic focussing l.focussing coil to adjust the intensity of mag- 'netsation of the pins by the magnetic field of the .focussing coil, said carrying member also being .rotatable with the respect to the axis of the gun,
15 L' to adjust the rotational position of 'said pins.
CYRUS H. BABBS..
REFERENCES CITED v'-I"lie'fo1-lowing references are of record in the file of this patent:
UNITED STATES `PATENTS vNumber
US730719A 1946-03-02 1947-02-25 Cathode-ray device Expired - Lifetime US2500623A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB6548/46A GB606005A (en) 1946-03-02 1946-03-02 Improvements in or relating to electromagnetically focussed and deflected cathode ray devices

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US2500623A true US2500623A (en) 1950-03-14

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BE (1) BE471546A (en)
FR (1) FR942329A (en)
GB (1) GB606005A (en)
NL (1) NL67155C (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2541446A (en) * 1949-01-04 1951-02-13 Barnet S Trott Image distortion corrector for cathode-ray tubes
US2602902A (en) * 1950-02-14 1952-07-08 Bendix Aviat Corp Sweep amplitude control for magnetically deflected cathode-ray tubes
US2790920A (en) * 1955-05-09 1957-04-30 Philco Corp Apparatus for control of electron beam cross section
US2876372A (en) * 1954-11-19 1959-03-03 Hazeltine Research Inc Color-image-reproducing apparatus
US2897390A (en) * 1955-12-23 1959-07-28 Glaser Steers Corp Magnetic convergence assembly
US2907908A (en) * 1955-09-01 1959-10-06 Philco Corp Apparatus for preventing distortion in plural beam cathode ray tubes
US2922908A (en) * 1955-08-31 1960-01-26 Westinghouse Electric Corp Retaining device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1995376A (en) * 1932-10-29 1935-03-26 Rca Corp Television system
US2157182A (en) * 1935-12-31 1939-05-09 Rca Corp Cathode ray deflecting device
US2177688A (en) * 1936-12-24 1939-10-31 Hazeltine Corp Cathode-ray tube scanning system
US2212640A (en) * 1934-07-07 1940-08-27 Radio Inventions Inc Cathode ray system
US2431077A (en) * 1943-08-31 1947-11-18 Rca Corp Cathode-ray tube with revolving magnets and adjustable sleeve

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1995376A (en) * 1932-10-29 1935-03-26 Rca Corp Television system
US2212640A (en) * 1934-07-07 1940-08-27 Radio Inventions Inc Cathode ray system
US2157182A (en) * 1935-12-31 1939-05-09 Rca Corp Cathode ray deflecting device
US2177688A (en) * 1936-12-24 1939-10-31 Hazeltine Corp Cathode-ray tube scanning system
US2431077A (en) * 1943-08-31 1947-11-18 Rca Corp Cathode-ray tube with revolving magnets and adjustable sleeve

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2541446A (en) * 1949-01-04 1951-02-13 Barnet S Trott Image distortion corrector for cathode-ray tubes
US2602902A (en) * 1950-02-14 1952-07-08 Bendix Aviat Corp Sweep amplitude control for magnetically deflected cathode-ray tubes
US2876372A (en) * 1954-11-19 1959-03-03 Hazeltine Research Inc Color-image-reproducing apparatus
US2790920A (en) * 1955-05-09 1957-04-30 Philco Corp Apparatus for control of electron beam cross section
US2922908A (en) * 1955-08-31 1960-01-26 Westinghouse Electric Corp Retaining device
US2907908A (en) * 1955-09-01 1959-10-06 Philco Corp Apparatus for preventing distortion in plural beam cathode ray tubes
US2897390A (en) * 1955-12-23 1959-07-28 Glaser Steers Corp Magnetic convergence assembly

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BE471546A (en)
GB606005A (en) 1948-08-04
FR942329A (en) 1949-02-04
NL67155C (en)

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