US2152820A - Braun tube - Google Patents

Braun tube Download PDF

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Publication number
US2152820A
US2152820A US745952A US74595234A US2152820A US 2152820 A US2152820 A US 2152820A US 745952 A US745952 A US 745952A US 74595234 A US74595234 A US 74595234A US 2152820 A US2152820 A US 2152820A
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United States
Prior art keywords
deflecting
plate
diaphragm
screen
electron
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
US745952A
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English (en)
Inventor
Schlesinger Kurt
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.)
Loewe Opta GmbH
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Loewe Opta GmbH
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 Loewe Opta GmbH filed Critical Loewe Opta GmbH
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Publication of US2152820A publication Critical patent/US2152820A/en
Anticipated expiration legal-status Critical
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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
    • H01J29/80—Arrangements for controlling the ray or beam after passing the main deflection system, e.g. for post-acceleration or post-concentration, for colour switching

Definitions

  • the invention relates to a Braun tube, more particularly for television purposes, in which merely comparatively low potentials are required for deflection of the ray, and means are provided 5 in order to make the form and size of the image point constant and independent of its intensity and of its position on the image screen.
  • the concentration is effected by field lines filling the entire space between the fluorescent screen and the electron gun.
  • the deflecting systems in this arrangement are situated within the concentration field itself, so that the distribution of the field in the vicinity of the first deflecting system is different 30 from that in the vicinity of the second deflecting system. In consequence it is impossible with these arrangements to operate with electrostatic deflecting systems.
  • the object of the invention is a Braun tube which allows of the production of completely regular images.
  • the controlled electronic ray is preliminarily concentrated onto a. diaphragm
  • the diaphragm is reproduced on the image screen by means of an electron-optical system, which acts preferably as a relatively thin collecting lens (of, for example, 3 cm. in thickness),
  • the deflection necessary for producing the line screen is performer prior to entry of the cathode ray into the lens, preferably in a completely fleldless space,
  • the deflection is preferably performed by a system, which causes both deflections in the same plane, for example according to the patent application Ser. No. 726,477, filed May 19, 1934.
  • FIG. 1 shows a possible total arrangement of the tube
  • Fig. 2 there is shown a particular form of embodiment of. the preliminary concentration system
  • Fig. 3 a form of embodiment of the deflecting system.
  • Figs. 4 and 5 show particular forms of embodiment of the lens according to the invention.
  • I is the bulb of the tube, which consists of the neck portion 2 and the preferably spherical envelope portion 3.
  • the fluorescent screen 4 may either be suspended in the bulb, or constructed inside the form of a fluorescent layer 5 applied in direct fashion to the wall of the bulb.
  • the electrons proceeding from the cathode 6, which conveniently is constructed in the form of an indirectly heated large surface cathode having an emissive layer sunk into the surface, are preliminarily concentrated on to the diaphragm. II] by means of a system consisting, for example, of, the cylinder 1 and the preliminary anode 8 and an additional cylinder 9.
  • the cylinder 1 may possess a weakly negative bias
  • the preliminary anode 8 and the diaphragm l0 may be raised to a weak positive potential (for example +300 Volts)
  • the potential of the cylinder 9 be weakly negative (for example +200 volts) in relation to the diaphragm 8.
  • the control takes place by applying the control alternating potential to the control plate ll arranged in the cylinder 1 preferably at a distance from the cathode 6 corresponding to the cathodic dark space with usual gas pressures and preferably in conductive connection with the cylinder.
  • the system. may be adjusted in such fashion that the electronic ray at its maximum intensity passes through the preferably small aperture l2 (for example 1 mm?) of the diaphragm [0 Without being partly stopped by said diaphragm l2 (for example 1 mm?) of the diaphragm Ill.
  • the diaphragm aperture I2 is reproduced on the fluorescent screen by means of the electronoptical system comprising the perforated plate I3 and the annular collar I4.
  • the spacing between the diaphragm to be reproduced and the lens (object spacing) on the one hand and between the lens and the fluorescent screen on the other hand may preferably be so selected (for example in the ratio of 2:1) that the diaphragm is reproduced on the image screen on reduced scale (for example 1:2).
  • the objeot spacing may be selected at 300 and the image spacing at 150 mm.
  • the annular plate I3 which is connected with a low positive potential-preferably the same potential as the diaphragm Ill-has at the same time the object of screening off the alternating field of the deflecting plates against the lens.
  • the deflecting system is situated in the entirely fieldless space between the electrodes I! and I3.
  • the space between these electrodes may be screened off towards the outside by means of a metallic tube connecting the electrodes or also by a metallic coating on the neck of the tube having a corresponding length and being raised to the same potential as the electrodes I and I3.
  • the second electrode of the electron-optical system, the annular plate I4, is preferably constructed, according to the invention, as a narrow or very narrow ring fitting closely against the wall of the bulb.
  • a part of the wall of the bulb between this electrode and the fluorescent screen is furnished with a metallic coating, which is conductively connected with the electrode I4, and in consequence possesses the same potential as this electrode (for example 2000 volts).
  • the wall of the bulb greatly recedes immediately behind the electrode, the relatively weak field formed between the electrode I4 and the fluorescent screen does not appreciably participate in the optical effect of the system.
  • the metallic coating of the bulb in substance produces the effect that the wall charges are neutralised and deformations in the shape of the image caused by the same avoided.
  • the cathode I the cylinder constructed as described in Fig. 1 with the control plate I I, 8 a preliminary anode, and I 0 the diaphragm with the aperture I2.
  • the system is adjusted in such fashion by suitable selection of the potentials that the cathode ray in the case of its maximum intensity passes through the aperture I2 without being partly stopped by the diaphragm I0.
  • the diameter of the cylinder I maybe selected at mm., the distance of the plate I I from the cylinder edge (the extent of introduction) at 1.5 mm., and the distance of the cylinder 1 from the plate 8 at 2 mm.
  • the deflecting systems are arranged in axial consecution, at a relatively large distance apart.
  • the line frequency deflection takes place by the use of an electrostatic field, whilst for frame frequency deflection purposes there is employed an electro-magnetic field.
  • the elements acting as static deflecting plates are then conveniently constructed themselves as pole shoes for the magnets causing the frame frequency deflection.
  • These plates in accordance with the invention, may also conveniently be tilted in relation to each other, or constructed in curved form.
  • FIG. 3 A form of embodiment of the deflecting system according to the invention is illustrated by way of example in Fig. 3.
  • I1 and I8 are the deflecting elements, which are supplied which on the one hand, in the manner known per se, with the potentials necessary for electrostatic deflection, and which at the same time are constructed as pole shoes for the magnets I9 and 20 causing the frame frequency deflection.
  • the elements I! and I8 are preferably constructed in such fashion that the same extend as closely as possible towards the Wall of the tube.
  • the tube I 6 connecting the diaphragms I0 and I3 (cf. Fig. 1) may in this case conveniently be furnished with recesses, through which the elements II and I8 project.
  • an electron lens may be employed in place of that set forth in Fig. 1.
  • the glass bulb I at that particular point at which the lens is to be mounted with two metallic annular coatings insulated one against the other, of which coatings the one is connected with a weak and the other with a strong positive potential.
  • the refractive power of the lens is determined in this case inter alia by the spacing between the two annular coatings, and may be adjusted as desired by variation of this spacing.
  • FIG. 4 A form of embodiment of a lens of this nature is illustrated by way of example in Fig. 4. In the same:
  • I is the glass envelope
  • I1 and I8 are the deflecting elements
  • I3 is the screening diaphragm.
  • is supplied with a weak positive potential (for example 300 volts) and the coating 15 with the anode potential (for example 2000 volts).
  • a diaphragm l4 which may consist of a narrow annular collar, and preferably be conductively connected with the metallic coating Hi.
  • the diaphragm M in ac cordance with the invention, may also be replaced by a small metallic tube 22, which extends for a short distance, for example mm.-3 cm. into the interior of the bulb (Fig. 5).
  • each of the systems is arranged strictly symmetrically with respect to the electronic lenses and to the tube axis and one plate of each pair is supplied with the respective deflecting voltage, While the other plate is supplied with a voltage of the same amplitude but reverse phase.
  • the necessary voltage of reverse phase may be easily produced with the use of a phase reverse valve controlled by the output voltage of one of the well known relaxation oscillation generators, said valve having a potentiometer arranged in its output circuit, the desired reverse phase voltage being tapped at said potentiometer so as to have the same potential as the original deflecting voltage.
  • a Braun tube for television purposes comprising an evacuated envelope enclosing a cathode, a modulating grid mounted in the vicinity of said cathode, a plate having an aperture, said plate being mounted in the vicinity of said grid, a picture receiving screen, an electrostatical electron-optical system mounted between said plate and said screen for reproducing said aperture on said screen, one pair of deflecting coils for deflecting the cathode ray in one direction, and one pair of deflecting plates for deflecting the cathode ray in a direction perpendicular to the first said one, said deflecting plates and said deflecting coils being mounted along the same axis, said deflecting plates being mounted between said plate. and said electron-optical system in close proximity to said system, the distance between said electron-optical system and said plate having said aperture being at least as great as the distance between said system and said screen.
  • a Braun tube for television purposes comprising an evacuated envelope enclosing a cathode, a modulating grid mounted in the vicinity of said cathode, a plate having an aperture, said plate being mounted in the vicinity of said grid, a picture receiving screen, an electrostatical electron-optical system mounted between said plate and said screen for reproducing said aperture on said screen, said electron-optical system comprising two electrodes, each of said electrodes comprising a cylinder having an apertured plate mounted therein and having an open cylindrical portion protruding beyond this apertured plate in the direction towards the other one of said electrodes, the two cylinders being adapted to have different constant potentials impressed thereon, and deflecting means for deflecting the cathode ray in two directions perpendicular to each other.
  • a Braun tube for television purposes comprising an evacuated envelope enclosing a cathode, a modulating grid mounted in the vicinity of said cathode, a plate having an aperture, said plate being mounted in the vicinity of said grid, a picture receiving screen, an electrostatical electron-optical system mounted between said plate and said screen for reproducing said aperture on said screen, said electron-optical system comprising two electrodes, each of said electrodes comprising a cylinder having an apertured plate mounted therein, the diameters of said cylinders being equal, the diameters of the apertures of the plates inserted in said cylinders being different from one another, said two cylinders being coaxially arranged and being adapted to have difierent potentials impressed thereon, and deflecting means for deflecting the cathode ray in two directions perpendicular to each other for scanning said picture receiving screen.

Landscapes

  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
US745952A 1933-10-02 1934-09-28 Braun tube Expired - Lifetime US2152820A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE446635X 1933-10-02

Publications (1)

Publication Number Publication Date
US2152820A true US2152820A (en) 1939-04-04

Family

ID=6537912

Family Applications (1)

Application Number Title Priority Date Filing Date
US745952A Expired - Lifetime US2152820A (en) 1933-10-02 1934-09-28 Braun tube

Country Status (4)

Country Link
US (1) US2152820A (fr)
FR (1) FR779741A (fr)
GB (1) GB446635A (fr)
NL (1) NL44152C (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2420176A (en) * 1941-05-28 1947-05-06 Rca Corp Cathode-ray tube with inclined target
US2533334A (en) * 1945-10-18 1950-12-12 Philco Corp Cathode-ray tube
US3432711A (en) * 1966-07-05 1969-03-11 Itt Hybrid deflection image dissector having concave deflection plates converging at horizontal edges of resolving apertures

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE739047C (de) * 1935-09-30 1943-09-09 Fernseh Gmbh Ablenkspulensystem fuer Elektronenstrahlroehren

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2420176A (en) * 1941-05-28 1947-05-06 Rca Corp Cathode-ray tube with inclined target
US2533334A (en) * 1945-10-18 1950-12-12 Philco Corp Cathode-ray tube
US3432711A (en) * 1966-07-05 1969-03-11 Itt Hybrid deflection image dissector having concave deflection plates converging at horizontal edges of resolving apertures

Also Published As

Publication number Publication date
FR779741A (fr) 1935-04-11
NL44152C (fr)
GB446635A (en) 1936-05-01

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