发明授权
- 专利标题: Display device also compatible with digital broadcasts
- 专利标题(中): 显示设备也兼容数字广播
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申请号: US09139116申请日: 1998-08-24
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公开(公告)号: US06288748B1公开(公告)日: 2001-09-11
- 发明人: Toshimitsu Watanabe , Yukimi Saiki , Kazuhiko Yoshizawa , Masahisa Tsukahara
- 申请人: Toshimitsu Watanabe , Yukimi Saiki , Kazuhiko Yoshizawa , Masahisa Tsukahara
- 优先权: JP9-238417 19970903
- 主分类号: H04N504
- IPC分类号: H04N504
摘要:
A display device which displays an image on a cathode-ray tube screen based on video information decoded from a signal-compressed digital broadcast signal. The video information contains fields having a number of scanning lines which may change from field to field, potentially causing vertical jitter in the displayed image. A circuit prevents the vertical jitter by setting a same vertical scanning start position of an electron beam on the screen for all of the fields regardless of the number of scanning lines. The circuit may be a clamp circuit which clamps a vertical ramp waveform; or a control circuit which controls a direct current level of the vertical ramp waveform when the number of scanning lines in a current field is different from a reference number of scanning lines; or an amplitude control circuit which performs feedback control of an amplitude of the vertical ramp waveform.