CATHODE-RAY TUBE DEVICE

• Main Author: ASHIZAKI SHIGEYA
• Format: Patent
• Language: English
• Published: 26.09.1991
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY

PURPOSE:To shorten the axial length of a deflecting yoke by disposing a magnetic body piece in an envelope in which a deflecting magnetic field is present, and working the deflecting magnetic field onto electron beams. CONSTITUTION:A miniature cathode-ray tube 1 has an electron gun 3 in the neck part 2a of an envelope 2 and a phosphor layer 4 on the inner surface of the face panel part 2b thereof. A permanent magnet 5 forms a magnetic focusing means giving focusing effect to electron beams together with magnetic pole pieces 6, 7. A deflecting yoke 13 for generating a deflecting magnetic field and a pair of ring magnets 14, 15 for centering are installed onto the outer circumferential surface of the envelope 2, and the yoke 13 has a gap (g) with the magnetic focusing means. The relative opposed end surfaces of magnetic body pieces 10, 11 are extended toward the electron gun 3 side phosphor layer 4. Thus, the main part of the horizontal deflecting magnetic field from the yoke 13 is focused on both the wing parts of the relative opposed end surfaces. As the focused and enhanced horizontal deflecting magnetic field is worked onto electron beams, the axial length of the yoke 13 can be shortened.