Cathode ray tube comprising a deflection unit
AssigneeU.S. Philips Corporation
InventorsDirk W. Harberts, Hendrik D. Van Den Berg, Robert T. M. Doedee
Life of this patent
Estimating the term…
Abstract
A cathode ray tube includes a deflection unit. A coil system of the deflection unit is provided with a conductive layer, the value for fmax/Δf ranging between 0.5 and 10, Δf being the half-value width of the impedance curve around a peak frequency fmax, and fmax being greater that 1 MHz. This results in a reduction of ringing phenomena.
Claims7
A cathode ray tube comprising an electron gun, a display screen and a deflection unit for deflecting the electron beam, which deflection unit includes a line deflection coil system and a frame deflection coil system, characterized in that the line deflection coils are at least partly provided with a conductive layer, and the impedance of the line deflection coil system exhibits a maximum at a frequency fmax of more than 1 MHz, and in that fmax/Δf ranges between 0.5 and 10, Δf being the half-value width of the impedance curve around fmax and/or in that the frame deflection coils are at least partly provided with a conductive layer, and the impedance of the frame deflection coil system exhibits a maximum at a frequency fmax of more than 0.3 MHz, and in that fmax/Δf ranges between 0.5 and 10.
A line deflection coil system, characterized in that the line deflection coils are at least partly provided with a conductive layer, and the impedance of the line deflection coil system exhibits a maximum at a frequency fmax of more than 1 MHz, and in that fmax/Δf ranges between 0.5 and 10, Δf being the half-value width of the impedance curve around fmax.
A frame deflection coil system, characterized in that the frame deflection coils are at least partly provided with a conductive layer, and the impedance of the frame deflection coil system exhibits a maximum at a frequency fmax of more than 0.3 MHz, and in that fmax/Δf ranges between 0.5 and 10, Δf being the half-value width of the impedance curve around fmax.
Dependencies are inferred from the claim text.