image display device

Abstract

Abstract PURPOSE:To reset a correct beam landing position and to prevent the deterioration of picture quality by correcting automatically the shift of the beam landing position due to the lapse of time, the temperature change, the fluctuation of AC voltage, etc. CONSTITUTION:A beam deflection amount detecting electrode 51 is formed by the Al vapor deposition on an insulated layer 50 of a horizontal focusing electrode 6 of a picture display device. Each electrode 51 is divided vertically into 32 pieces, and the prescribed electrodes are connected to each other within a section of the electrode 51. Then a beam absorbing electrode 52 is formed between electrodes 51 by the Al vapor deposition. A microcomputer 54 is connected to a prescribed number of electroded 51 connected to each other via an A/D converter 53. When the electron beam is delfected vertically for each of divided sections, etch electrode 51 detects the shift of the beam landing position due to the lapse of time, the temperature change, the fluctuation of AC voltage, etc. Then this position shift is corrected automatically by a control circuit to avoid the deterioration of picture quality.

Inventors

• 👤 Takatsugu Kurata
• 👤 隆次 倉田
• 👤 Junpei Hashiguchi
• 👤 淳平 橋口
• 👤 Minoru Ueda
• 👤 稔 上田

Bibliographic Details