US2387110A - Electrical apparatus - Google Patents

Electrical apparatus Download PDF

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Publication number
US2387110A
US2387110A US459018A US45901842A US2387110A US 2387110 A US2387110 A US 2387110A US 459018 A US459018 A US 459018A US 45901842 A US45901842 A US 45901842A US 2387110 A US2387110 A US 2387110A
Authority
US
United States
Prior art keywords
coils
tube
flux
deflection
magnetic circuit
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
US459018A
Other languages
English (en)
Inventor
Bedford Leslie Herbert
Stevens Walter Henry
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.)
AC Cossor Ltd
Original Assignee
AC Cossor Ltd
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
Priority to NL60535D priority Critical patent/NL60535C/xx
Priority to GB13915/38A priority patent/GB519668A/en
Priority to GB14005/39A priority patent/GB519715A/en
Priority to US272508A priority patent/US2336837A/en
Priority claimed from US272508A external-priority patent/US2336837A/en
Priority to FR854515D priority patent/FR854515A/fr
Priority to CH212037D priority patent/CH212037A/fr
Application filed by AC Cossor Ltd filed Critical AC Cossor Ltd
Priority to US459018A priority patent/US2387110A/en
Publication of US2387110A publication Critical patent/US2387110A/en
Application granted granted Critical
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • H01J29/72—Arrangements for deflecting ray or beam along one straight line or along two perpendicular straight lines
    • H01J29/76—Deflecting by magnetic fields only
    • H01J29/766—Deflecting by magnetic fields only using a combination of saddle coils and toroidal windings
    • 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
    • H01J29/54—Arrangements for centring ray or beam
    • 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
    • H01J29/58—Arrangements for focusing or reflecting ray or beam
    • H01J29/64—Magnetic lenses
    • H01J29/68—Magnetic lenses using permanent magnets only

Definitions

  • the invention relates to an electromagnetic system for the deflection of the electron beam of a cathode ray tube in two mutually perpendicular directions.
  • An object of the invention is to provide a robust and compact assembly of deflection coils for the two directions of deflection.
  • a further object is to minimize mutual interference between the currents passed through the deflection coils and mutual interference between the electromagnetic deflection fields produced thereby.
  • Figure 1 shows a perspective View of an electromagnetic deflecting apparatus surrounding the neck of a cathode ray tube suitable for a television receiver
  • Figure 2 is a diagrammatic sectional view of Figure 1 taken on the plane of the central lamination II.
  • the electron gun (which includes the cathode) and the fluorescent screen are not shown, but the former is assumed to be situated below, and the latter above, the assembly shown, so that the electron beam passes upward through the neck I of the cathode ray tube.
  • the two coils I produce one of the electromagnetic deflection fields and the coils 8 produce the other.
  • Each of these fields is of the kind comprising a central flux path passing transversely through the neck of the tube and comprising two symmetrical side paths passing on mutually opposite sides of the neck of the tube.
  • the coil l are bent around to lie in Contact with the former 6 which is a sleeve of insulating material closely surrounding the neck of the tube.
  • the central fiux path of the field of the coils 1 passes through the neck of the tube in the direction of the common axis 1' of the coils i, see Figure 2.
  • the coils 8 have their centres substantially on the common axis 1 of the coils l, but their own axes are perpendicular to the axis of the coils l.
  • the central flux path of the field of the coils 8 passes through the neck of the tube in the direction 8 parallel-to the axes of the coils 8, see Figure 2.
  • laminations H The part of the magnetic circuit of the coils 8 external to the tube is formed by laminations H in the form of complete rectangles of ferromagnetic materials. These laminations are spaced apart by wooden spacers l2.
  • the part of the magnetic circuit of the coils external to the tube is formed by laminations ea, 9c of ferromagnetic material. These are divided, the part 9a, in the form of a complete rectangle, being placed on the end of the assembly nearer the fluorescent screen, and the other part 90, forming substantially a rectangle, being placed on the end of the assembly nearer the cathode.
  • the part 9b, 9c is subdivided into two U-shaped parts by the provision of gaps in the region of the ends of the central flux path of the magnetic circuit belonging to the coils 1. These gaps minimize the short-circuiting of the magnetic circuit of the coils 8.
  • the laminations 9a, 9b, 9c are spaced from the two outer laminations H by wooden spacers l0, and are thus arranged at the ends of the coils 1.
  • the central fillX path for coils l is directed along the axis 1 of these coils, while the central flux path for the coils 8 is directed along the axi 8 parallel to the axes of these coils but at right angles to the axis l.
  • the flux from the central path along axis 1 divides, and a portion represented by the link of dotted arrows la forms one side path for this magnetic circuit and the other portion represented by the link of dotted arrows 11) forms the other side path for thi circuit, these side paths being completed partly through lamination 9a.
  • the flux from the central path along axis 8 divides, a portion going through one coil 8 surrounding one leg of lamination II and the other portion going through the other coil 8 surrounding the opposite leg of the lamination.
  • the electromagnetic pickup of the coils 8 resulting from current changes in the coils l is neutralized.
  • coils i surround the central flux path of one deflecting magnetic circuit whereas coil 8 are linked separately with the side paths only of the other deflecting magnetic circuit.
  • the coils 8 may be arranged for adjustment in the direction of their axes so as to provide for accurate adjustment of this neutralisation.
  • the coils 8 should preferably be enclosed in electrostatic screens to minimise electrostatic interference between the two pairs of coils.
  • the coils I should preferably be so electrically connected in ther circuit as to be operated in respect to alternating current, symmetrically'about earth. This is diagrammatically indicated in the drawing by showing the terminals (3 of the circuit for coils 1 connected by leads one to each coil, and by showing the other leads from each coil connected together and earthed at Hi.
  • the coils 8 are employed to produce the lower frequency or frame deflection and the coils to produce higher frequency or line deflection.
  • the laminations 8 are preferably then made of Rhometal and the laminations H of Stalloy.
  • the ratio of permeability at line frequency to permeability at frame frequency is substantially higher for Rhometal than for Stalloy.
  • a cathode ray tube having a compact electromagnetic deflection system including magnetic circuits for controlling the electron beam in two mutually perpendicular directions of deflection, each of which comprises a central flux path passing through the tube and two side paths for the flux which pass on mutually opposite sides of the tube, the combination of coils for producing the flux to control the deflection in one direction positioned about a common axis and on opposite sides of the tube about the central flux path of a first magnetic circuit, and coils for producing the flux to control the deflection in a perpendicular direction positioned on side flux paths of a second magnetic circuit with their centres substantially on said common axis at opposite sides of the tube and with their axes perpendicular to said common axis.
  • a cathode ray tube having a compact electromagnetic deflection system including magnetic circuits for controlling the electron beam in two mutually perpendicular directions of deflection, each of which comprises a central flux path passing through the tube and two side paths for the flux which pass on mutually opposite sides of the tube, the combination of coils for producing the flux to control the deflection in one direction positioned about a common aXis and on opposite sides of the tube about the central flux path of a first magnetic circuit, and coils for producing the flux tocontrol the deflection in a perpendicular direction positioned on side flux paths of a second magnetic circuit with their centres substantially on said common axis at opposite sides of the tube and with their axes perpendicular to said common axis, the coils'for producing electromagnetic flux in said second magnetic system being moveably supported for adjustment in the direction of their axes.
  • a cathode'ray'tube' having a compact electromagnetic deflection system including magnetic circuits for controlling the electron beam in two mutually perpendicular directions of deflection, each of which comprises a central flux path passing through the tube and two side paths for the flux which pass on mutually opposite sides of the tube, the combination of coils for producing the flux to control the deflection in one direction positioned about a common axis and on opposite sides of the tube about the central flux path of a first magnetic circuit, means for maintaining the electrical central point of said coils at a constant potential, and coils for producing the flux to control the deflection in a perpendicular direction positioned on side flux paths of a second magnetic circuit with their centres substantially on said common axis at opposite sides of the tube and with their axes perpendicular to said common axis.
  • a cathode ray tube having a compact electromagnetic deflection system including magnetic circuits for controlling the electron beam in two mutually perpendicular directions of deflection, each of which comprises a central flux path passing through the tube and two side paths for the flux which pass on mutually opposite sides of the-tube, the combination of coils for producing the flux to control the deflection in one direction positionedabout'a common axis and on opposite sidesof the tube about the central flux path of a firstmagnetic circuit, means for grounding the centre point of said coils, and coils for producing the flux to control the deflection in a perpendicular direction positioned on side flux paths of a second magnetic circuit with their centres substantially on said common axis at opposite sides of the tube and with their axes perpendicular to said common axis.
  • a cathode raytube having a compact electromagnetic deflection system including magnetic circuits for controlling the electron beam in two mutually perpendicular directions of deflection, each of which comprises a central flux path passing through the tube and two side paths for the flux which pass on mutually opposite sides of the tube, the combination of coils for producing the flux to control the deflection in one direction positioned about a common axis and on opposite sides of the tube about the central flux path of a first magnetic circuit, coils for producing the flux to control the deflection in a perpendicular direction positioned on side flux paths of a second magnetic circuit with their centres substantially on said common axis at opposite sides of the tube and with their axes perpendicular to said common axis, a ferromagnetic path for said second magnetic circuit, and a divided ferromagnetic path for said'first magnetic circuit, the divided portions of which being oppositely displaced from the second magnetic circuit in the direction parallel to the electron beam path.
  • a cathode ray tube having a compact electromagnetic deflection system including magnetic circuits for controlling the electron beam in two mutually perpendicular directions of deflection at substantially difierent'frequencies of fleld flux, each of which comprises a central flux path passing through the tube and two ferro-magnetic paths external of the tube for the flux which passes on mutually opposite sides of the tube, the combination of ferromagnetic means providing external paths for eachof said magnetic circuits, the external ferromagnetic paths of the magnetic circuit carrying the higher frequency of field flux having a substantially greater ratio of permeability at high frequencies to permeability at low frequencies than have the external ferromagnetic paths of the magnetic circuit carrying the field flux of lower frequency.

Landscapes

  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Details Of Television Scanning (AREA)
  • Transforming Electric Information Into Light Information (AREA)
US459018A 1938-05-10 1942-09-19 Electrical apparatus Expired - Lifetime US2387110A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
NL60535D NL60535C (enrdf_load_stackoverflow) 1938-05-10
GB13915/38A GB519668A (en) 1938-05-10 1938-05-10 Improvements relating to cathode ray tubes
GB14005/39A GB519715A (en) 1938-05-10 1938-05-10 Improvements relating to cathode ray tubes
US272508A US2336837A (en) 1938-05-10 1939-05-08 Electrical apparatus
FR854515D FR854515A (fr) 1938-05-10 1939-05-09 Perfectionnements aux systèmes de télévision utilisant des tubes à rayons cathodiques
CH212037D CH212037A (fr) 1938-05-10 1939-05-09 Tube à rayons cathodiques.
US459018A US2387110A (en) 1938-05-10 1942-09-19 Electrical apparatus

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB212037X 1938-05-10
US272508A US2336837A (en) 1938-05-10 1939-05-08 Electrical apparatus
US459018A US2387110A (en) 1938-05-10 1942-09-19 Electrical apparatus

Publications (1)

Publication Number Publication Date
US2387110A true US2387110A (en) 1945-10-16

Family

ID=32110572

Family Applications (1)

Application Number Title Priority Date Filing Date
US459018A Expired - Lifetime US2387110A (en) 1938-05-10 1942-09-19 Electrical apparatus

Country Status (5)

Country Link
US (1) US2387110A (enrdf_load_stackoverflow)
CH (1) CH212037A (enrdf_load_stackoverflow)
FR (1) FR854515A (enrdf_load_stackoverflow)
GB (2) GB519668A (enrdf_load_stackoverflow)
NL (1) NL60535C (enrdf_load_stackoverflow)

Also Published As

Publication number Publication date
CH212037A (fr) 1940-10-31
NL60535C (enrdf_load_stackoverflow)
GB519668A (en) 1940-04-03
GB519715A (en) 1940-04-03
FR854515A (fr) 1940-04-17

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