| 摘要 |
PURPOSE:To display a color image with a high color purity by spreading an index phosphor at least at the borders of display rears of sections on a fluorescent screen, and providing a control means to detect the signal output from the index phosphor, and to control the deflecting amount and the current amount of plural electron beams separately. CONSTITUTION:An emitting means of electron beams 10 emits plural electron beams 10 parallel to a fluorescent screen 2, a deflecting means of electron beams 10 deflects each electron beam to the fluorescent screen 2, and each display area on the fluorescent screen 2 is scanned. Index beams are radiated from the index phosphor spread on the fluorescent screen by the scanning of the electron beams 10. A detecting means 7 of the index signal detects the index beams, converts them into electric signals, and delivers them to a means 8 to control the emission and the deflection of the electron beams 10. In the control means 8, the features of index signals are stored, and the stored signals are read when the cathode-ray tube is driven, so as to control the drive of the emitting means and the deflection means of the electron beams 10. Consequently, a color image of a high color purity along the whole area of the image screen can be displayed. |
