JPH0248994U - - Google Patents

Description

[Brief explanation of drawings]

1 and 2 are block diagrams and specific circuit diagrams showing the configuration of a dynamic focus device according to an embodiment of the present invention, and FIGS. 3a and 3b are horizontal and vertical scanning frequency system circuits in the embodiment. 4a and 4b are waveform diagrams illustrating the operation of the mixing and summing amplifier in the above embodiment, and FIG. 5 is a waveform diagram illustrating the operation in the above embodiment. Figures 6a and b are dynamic focus potential diagrams for the cathode ray tube screen surface and their M-N cross-sectional views, and Figures 7a to d are various gain adjustment forms. FIG. 8 is a waveform diagram showing the output changes of the mixing and summing amplifier. FIG. 8 is a configuration diagram showing the main parts of the cathode ray tube.
Figures a and b are explanatory waveform diagrams of parabolic waves, Figures 10 a and b are main configuration diagrams of a conventional dynamic focus device, and Figure 11 is an explanation of the flat surface of the screen plate and the widening of the deflection angle. Figures 12a to 12e are illustrations of focus deterioration due to positional deviations of the electron gun cathode, deflection yoke, etc., and Figures 13a to d are illustrations of spot blur caused by tilting of the deflection center of the deflection yoke. Explanatory diagram, Figure 14a
, b are waveform diagrams illustrating the conventional dynamic focus method, and FIG. 15 is an explanatory diagram showing the phase relationship between the screen display of the cathode ray tube and the parabolic wave. 8, 17...Horizontal and vertical flyback pulses,
10, 18... prephase shift circuit, 12, 2
0... A monostable multi-pulse generator that constitutes a phase shift correction circuit together with the prephase shift circuit, 13
, 21... sawtooth wave generator, 15, 23... parabolic wave generator, 27... main focus amplifier, 28...
Coupling capacitor, 29, 30, 31...diode, resistor, and capacitor constituting the clamp circuit,
33... Focus electrode, 11, 14, 16, 19
, 22, 24, 32...variable resistor.

Claims (1)

[Scope of utility model registration request] A sawtooth that has a phase shift correction circuit that outputs a phase shift pulse of the flyback pulse, and a variable resistor that also serves as polarity inversion and gain adjustment, and that generates a predetermined sawtooth wave based on the output of the phase shift correction circuit. horizontal and vertical scanning frequency system circuits each comprising a parabolic wave generator and a parabolic wave generator that has a variable resistor for gain adjustment and generates a predetermined parabolic wave based on a sawtooth wave input; , the outputs of the sawtooth wave generator and the parabolic wave generator of the horizontal and vertical scanning frequency system circuits are added to obtain a synthesized horizontal and vertical periodic dynamic focus wave, and these are superimposed to generate a dynamic focus wave. A mixing summing amplifier that obtains a focused parabolic mixed wave, a main focus amplifier that amplifies its output, and a variable resistor for adjusting the reference potential that is provided at the intersection of the coupling capacitor and the focus electrode connected to the output terminal of this amplifier. 1. A dynamic focus device comprising: a clamp circuit having a clamp circuit;