GB570213A - Improvements in or relating to cathode-ray tubes - Google Patents

Abstract

570,213. Cathode-ray tubes. KLEM PERER, O. E. H. Feb. 13, 1943, No. 2406. [Class 39 (i)] An electron beam is deflected by passing it through an electrode 31, Fig. 6, which substantially surrounds the beam and has an obliquely formed end 5. The electrode may be associated with one or more electrodes 32, 33, 34 with complementary oblique ends, the direction of the plane of separation alternating as the sign of the deflection potential on,successive electrodes changes. Alternatively, the oblique end 6 may project into a larger cylindrical electrode 23, which may be a coating on the neck of the cathode-ray tube ; a disc 24 seals off the space between electrodes 34 and 23, leaving only a narrow gap. The shorter side 14 of an electrode may vanish altogether, the electrodes on either side being joined at this point. The electrodes may also be formed by cutting a circular cylinder or their cross-section may expand progressively along the path of the beam. Deflection in two perpendicular directions may be obtained by cutting the electrodes in planes at right angles, the electrodes 41, 42, 43, Fig. 7, deflecting the beam in one direction and electrodes 43, 44, 45 in the other direction ; three electrodes will suffice for this purpose, for example, electrodes 42, 43, 44 with gaps 6, 5<1> only. Alternatively, deflection in one direction may be by simple deflecting plates. The oblique end need not be plane, since it may be curved as shown at 60, Fig. 9, to equalize the deflection sensitivity over the whole range of deflection or to obtain some other desired law, or a simple circular arc may be used to give a lens effect. Specification 525,000 is referred to. Reference has been directed by the Comptroller to Specification 561,905.