US3930180A - Color cathode ray tube magnetic pole piece support structure - Google Patents

Color cathode ray tube magnetic pole piece support structure Download PDF

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Publication number
US3930180A
US3930180A US466388A US46638874A US3930180A US 3930180 A US3930180 A US 3930180A US 466388 A US466388 A US 466388A US 46638874 A US46638874 A US 46638874A US 3930180 A US3930180 A US 3930180A
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US
United States
Prior art keywords
pole shoes
ray tube
cathode
pairs
color
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
US466388A
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English (en)
Inventor
Leeuwen Johannes Aloysius Van
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
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US Philips Corp
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Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
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Publication of US3930180A publication Critical patent/US3930180A/en
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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
    • H01J29/70—Arrangements for deflecting ray or beam
    • H01J29/701—Systems for correcting deviation or convergence of a plurality of beams by means of magnetic fields at least
    • H01J29/707—Arrangements intimately associated with parts of the gun and co-operating with external magnetic excitation devices
    • 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
    • H01J29/82—Mounting, supporting, spacing, or insulating electron-optical or ion-optical arrangements

Definitions

  • the invention relates to a cathode-ray tube for displaying colored pictures and comprising in' an evacuated envelope means to generate a number of electron beams, a display screen comprising a large number of regions luminescing in different colors, a color selection electrode having a large number of apertures, and means to converge the electron beams on the display screen, which electron beams each are assigned to luminescent regions of one color by means of said color selection electrode, said convergence means comprising a cylindrical sleeve to which are secured a number of pairs of ferromagnetic pole shoes extending radially inwards.
  • Such a cathode-ray tube is known from the US. Pat. No. 3,643,121.
  • the relevant electron beam can be slightly deflected in a radial direction. This is carried out in such manner that the electron beams intersect each other substantially in one point at the area of the display screen.
  • the simple construction of the internal convergence unit known from the said patent specification suffers from the drawback that the distance between the pole shoes of one pair is not determined sufficiently accurately.
  • a cathode ray tube of the type mentioned in the first paragraph is characterized in that means are present to fix the inwardly directed ends of the pole shoes, which means are preferably such that the inwardly directed ends of the pole shoes are pressed against a support under the influence of the resilience of the pole shoes.
  • Said support is preferably manufactured from one piece and comprises a central portion which is secured to a base plate of the said cylindrical sleeve, and a lug which is bent in the axial direction for each pair of pole shoes.
  • FIG. 1 shows a cathode-ray tube for displaying colored pictures according to the invention
  • FIG. 2 is an elevation of the internal convergence unit of said tube
  • FIG. 3 is an axial cross-sectional view of said internal convergence unit
  • FIG. 4 shows supporting means for the ends of the pole shoes and FIG. 5 explains an alternative method of supporting.
  • the cathode-ray tube shown in FIG. 1 for displaying colored pictures is of the shadow mask type and comprises: an evacuated glass envelope 1, a set of electron guns 2 in triangular arrangement for producing three electron beams 3, 4 and 5, a display screen 6 comprising a large number of phosphor dots luminescing in red, green and blue, respectively, a color selection electrode 7 having a large number of apertures 8, and a set of deflection coils 9 for scanning the display screen 6 with the electron beams 3, 4 and 5.
  • the electron beams .3, 4 and 5 are converged on the display screen 6 by means of an internal convergence unit 10 and an external convergence'unit 'l 1.
  • the internal convergence unit 10 comprises a cylindrical sleeve' 12 which is coaxial with the axis 13 of the tube.
  • FIG. 2 is anelevation of the internal convergence unit 10 viewed from the side of the shadow mask 7.
  • the cooperation of the internal convergence unit 10 with the external convergence unit 1 l is shown diagrammatically with an external magnetic circuit 14 having a coil 15.
  • a current through the coil 15 produces a magnetic field between the pole shoes 16 and 17 which causes a radial displacement of the electron beam 5.
  • the electron beam 3 is influenced in the same manner by the field between the pole shoes 18 and 19 and the electron beam 4 is influenced by the field between the pole shoes 20 and 21. In this manner the electron beams 3, 4 and 5 can be converged in a point on the display screen 6.
  • the pairs of poleshoes are screened relative to each other by ferromagnetic partitions 22, 23 and 24.
  • the cylindrical sleeve 12 has a base plate 25 which comprises three apertures for passing the electron beams 3, 4 and 5.
  • FIG. 3 is a cross-sectional view for further explanation of the construction taken on the plane IIIIII of FIG. 2.
  • the ends of the pole shoes are kept spaced apart by a support 26 which is stamped from one piece and which is shown in detail in FIG. 4.
  • the pole shoes are not secured to the support 26 but are pressed against it as a result of their own resilience.
  • the support 26 comprises a central portion 27 which is spotwelded to the base plate 25 and three lugs 28, 29 and 30 which are bent in an axial direction and have bent ends 31, 32 and 33 for keeping the poleshoes spaced apart.
  • the resilience of the poleshoes may of course also act in the opposite direction as is shown in FIG. 5.
  • the poleshoes 16, l7, 18, 19, 20 and 21 project through slots in the cylindrical sleeve 12 and have bent ends (for example, 34 for poleshoe 21) which are secured to the sleeve 12 by means of spot welds.
  • bent ends for example, 34 for poleshoe 21
  • the distance between the poleshoes of one set was determined entirely by the accuracy with which the end 34 had been bent.
  • the distance is determined only by the support 26 which can be punched with great accuracy. Nevertheless the poleshoes need be welded only to the cylindrical sleeve 12 so that the simplicity of the construction is maintained.
  • the invention has been explained with reference to a tube having three electron guns in triangular arrangement, the invention is, of course, not restricted to such a tube. If, for example, the three electron guns are situated with their axes in one flat plane the invention can also be used in which, for example, only pairs of poleshoes are present for the two extreme beams.
  • a cathode-ray tube for displaying color pictures comprising an evacuated envelope and, within said envelope, means to generate a plurality of electron beams, a display screen having a plurality ofregions luminescing in different colors, a color selection electrode having a plurality of apertures to assign each electron beam to luminescent regions of one color, convergence means including a cylindrical'sleeve, a plurality of pairs of ferromagnetic pole shoes secured to said sleeve and extending radially inwards to con- 4 means including a support having a central portion secured to said base plate and a plurality of lugs projecting between the free ends of respective pairs of pole shoes.

Landscapes

  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
US466388A 1973-05-21 1974-05-02 Color cathode ray tube magnetic pole piece support structure Expired - Lifetime US3930180A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7307040A NL7307040A (enrdf_load_stackoverflow) 1973-05-21 1973-05-21

Publications (1)

Publication Number Publication Date
US3930180A true US3930180A (en) 1975-12-30

Family

ID=19818899

Family Applications (1)

Application Number Title Priority Date Filing Date
US466388A Expired - Lifetime US3930180A (en) 1973-05-21 1974-05-02 Color cathode ray tube magnetic pole piece support structure

Country Status (10)

Country Link
US (1) US3930180A (enrdf_load_stackoverflow)
JP (1) JPS5020615A (enrdf_load_stackoverflow)
BE (1) BE815305A (enrdf_load_stackoverflow)
CA (1) CA993027A (enrdf_load_stackoverflow)
DE (1) DE2422163A1 (enrdf_load_stackoverflow)
ES (1) ES426448A1 (enrdf_load_stackoverflow)
FR (1) FR2231104B1 (enrdf_load_stackoverflow)
GB (1) GB1425427A (enrdf_load_stackoverflow)
IT (1) IT1014207B (enrdf_load_stackoverflow)
NL (1) NL7307040A (enrdf_load_stackoverflow)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS556047U (enrdf_load_stackoverflow) * 1978-06-27 1980-01-16

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3548249A (en) * 1968-02-05 1970-12-15 Sony Corp Color cathode ray tube of the pluralbeam,single electron gun type
US3728569A (en) * 1970-09-17 1973-04-17 Philips Corp Cathode-ray tube

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2847598A (en) * 1956-04-16 1958-08-12 Rca Corp Electron gun structure for plural beam tubes
BE755822A (fr) * 1969-09-12 1971-02-15 Rca Corp Canon pour tube a rayons cathodiques comportant un montage d'electrodesemboitees

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3548249A (en) * 1968-02-05 1970-12-15 Sony Corp Color cathode ray tube of the pluralbeam,single electron gun type
US3728569A (en) * 1970-09-17 1973-04-17 Philips Corp Cathode-ray tube

Also Published As

Publication number Publication date
ES426448A1 (es) 1976-07-01
GB1425427A (en) 1976-02-18
FR2231104B1 (enrdf_load_stackoverflow) 1977-06-24
IT1014207B (it) 1977-04-20
DE2422163A1 (de) 1974-12-12
BE815305A (fr) 1974-11-20
NL7307040A (enrdf_load_stackoverflow) 1974-11-25
CA993027A (en) 1976-07-13
JPS5020615A (enrdf_load_stackoverflow) 1975-03-05
FR2231104A1 (enrdf_load_stackoverflow) 1974-12-20

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