| 摘要 |
PROBLEM TO BE SOLVED: To provide a cathode ray tube display device which automatically corrects a positional displacement of a displayed video influenced by the geomagnetism. SOLUTION: A display picture, of which the display position is displaced by the influence of the vertical component of the geomagnetism, is moved back to a predetermined position, and the displacements of the displayed picture toward left and a horizontal trapezoidal distortion are improved in worsening, by inputting a signal from a geomagnetism detecting part 1 to a calculating means 22 via an A/D converter 21, calculating a control signal by using a positional parameter of a moving amount of the displayed picture to a predetermined vertical component of the geomagnetism, sending the calculated digital data to a current circuit via a D/A converter 23 to increase or decrease a DC current required for correction, and superposing the current in a horizontal deflection output circuit via a current superposing circuit 8 and thereby putting back the displayed picture to the predetermined position. |
