Deflecting device for a cathode ray tube
AssigneeInternational Business Machines Corporation
InventorMasaharu Kawamura
Life of this patent
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Abstract
A deflector for a cathode ray tube (called herein "CRT"), and more particularly a stator type deflector in which a plurality of slots for windings are formed in the inner surface of a tubular core and deflecting coils are positioned in these slots. Both convergence (spot) distortion and raster (pin cushion) distortion are small. The magnetic field distribution at the neck is a barrel type, and that at the screen is a pin cushion type. Both the horizontal and the vertical magnetic fields are obtained by adjusting the positioning of the winding slots formed in the inner surface of the tubular core for positioning the deflecting coils. This is accomplished by adjusting the angles of the plurality of winding slots formed in the inner surface of the tubular core which contain the deflecting coils.
Claims10
In a deflecting device for a cathode ray tube in which a plurality of winding slots are formed in the inner surface of a tubular core, in which slots deflecting coils are positioned, when .theta.ni is an angle in a plane normal to the tube axis at the neck between a line connecting said tube axis to the center of said winding slot in the transverse direction and a reference line in the horizontal direction, and .theta.si is an angle in a plane normal to the tube axis at the screen between a line connecting said tube axis to the center of said winding slot in the transverse direction and a reference line in the horizontal direction, said winding slots being formed to be
- .theta.ni>.theta.si
- in a first region of said tubular core,
- ni=.theta.si
- in a second region of said tubular core, and
- .theta.ni<.theta.si
- in a third region of said tubular core.
In a deflecting device for a cathode ray tube in which a plurality of winding slots are formed in the inner surface of a tubular core, in which slots deflecting coils are positioned, comprising:
- means for obtaining barrel distribution of the magnetic at the neck side of said tube and obtaining pin cushion distribution of the magnetic field at the screen side for both the horizontal and the vertical deflection magnetic fields, by adjusting the positioning of the winding slots in the inner surface of the tubular core,
- whereby no dispersion is caused in the distribution of of the magnetic fields and there is high deflection efficiency, and there are attained both reduction of raster distortion and improvement of convergence.
A deflecting device for a cathode ray tube having a neck and a screen, said deflecting device comprising:
- a tubular core having an inner surface comprising a plurality of winding slots, said tubular core having a neck end arranged toward the neck of the cathode ray tube, said tubular core having a screen end arranged toward the screen of the cathode ray tube, said tubular core having an axis extending from the neck end to the screen end of the tubular core;
- at least one deflecting coil arranged in the winding slots;
- characterized in that:
- there is a normal plane which is normal to the axis of the tubular core;
- an angle .theta.ni is formed between the projections in the normal plane of (i) a line connecting the tube axis to the center of the i'th winding slot at the neck end of the tubular core, and (ii) a reference line in a horizontal direction;
- an angle .theta.si is formed between the projections in the normal plane of (i) a line connecting the tube axis to the center of the i'th winding slot at the screen end of the tubular core, and (ii) the reference line in the horizontal direction;
- in a first region of the tubular core the winding slots satisfy .theta.ni>.theta.si;
- and
- in a second region of the tubular core the winding slots satisfy .theta.ni<.theta.si.
Dependencies are inferred from the claim text.