Title:
FOCUS CIRCUIT
Document Type and Number:
Japanese Patent JP3237723
Kind Code:
B2
Abstract:
PURPOSE: To optimize focusing over the entire screen of a CRT by respectively separately generating the dynamic focus voltage of a parabolic waveform for red, green and blue.
CONSTITUTION: The respective voltages for focus adjustment of the CRT for red, green and blue are respectively supplied from a DC high voltage impressed to an MV terminal in a focus circuit 10 through resistors R1, R2 and R3 to a terminal Fv. On the other hand, respective parabolic waveform voltages for red, green and blue channels are respectively generated by red, green and blue dynamic focus circuits 20R, 20G and 20B and respectively superimposed through CR, CG and CB to the focus adjusting voltages for red, green and blue. Thus, since the parabolic waveforms in red, green and blue are separately corrected corresponding to the fluctuation of an anode voltage at the CRT, focusing can be optimized over the entire screen of the CRT.
Inventors:
Satoshi Ohsuka
Kawabata Yasunobu
Tadashi Usui
Kawabata Yasunobu
Tadashi Usui
Application Number:
JP3455693A
Publication Date:
December 10, 2001
Filing Date:
January 29, 1993
Export Citation:
Assignee:
ソニー株式会社
International Classes:
H04N3/16; H04N3/26; H04N5/68; (IPC1-7): H04N3/26
Domestic Patent References:
| JP62256579A | ||||
| JP61276481A | ||||
| JP5895472A | ||||
| JP279665U | ||||
| JP6258960U |
Attorney, Agent or Firm:
Yoshio Inamoto