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公开(公告)号：US4907116A
公开(公告)日：1990-03-06
申请号：US204474
申请日：1988-06-09
CPC分类号： H02H7/122 , H02H7/1213
摘要： A MOSFET power switching transistor in a DC-to-DC converter of a television apparatus has a drain electrode that is coupled via a primary winding of a chopper transformer to an input supply voltage. A first signal at a given frequency causes, during normal operation, alternate conduction and nonconduction in the transistor. A second signal is generated that is proportional to the voltage developed across the internal "on" resistance of the transistor when the transistor is conductive. The second signal is clamped when the MOSFET transistor is nonconductive. The second signal is coupled via a current sensing arrangement to the transistor gate. The second signal prevents the transistor from further conducting when the amplitude of the second signal exceeds a predetermined value that corresponds with a predetermined limiting threshold level of current in the transistor.
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公开(公告)号：US4894716A
公开(公告)日：1990-01-16
申请号：US341076
申请日：1989-04-20
申请人： Felix Aschwanden , Theodor E. Bart
发明人： Felix Aschwanden , Theodor E. Bart
IPC分类号： H04N5/262 , G06T7/20 , G08B13/194 , H04N5/14 , H04N7/18 , H04N7/26 , H04N7/36 , H04N9/77 , H04N11/04
CPC分类号： G08B13/19602 , G06T7/2033 , G08B13/19606 , G08B13/19634 , H04N19/503 , H04N5/144
摘要： A motion detector which compares the video signal from a camera to a camera signal from an earlier scene and produces an alarm signal if an edge of any object has changed its position, but protects against false signals. A phase detector is used to sense movement in only the edges of objects and a vertical coincidence circuit requires object movement in several vertical video lines to prevent false signals from such small items as raindrops. Several adjacent horizontal areas must also show movement in order to activate an alarm.
摘要翻译： 运动检测器，其将来自相机的视频信号与来自较早场景的摄像机信号进行比较，并且如果任何物体的边缘已经改变其位置，并且防止假信号，则产生报警信号。 相位检测器仅用于检测物体边缘的运动，垂直重合电路需要物体在若干垂直视频线路中移动，以防止诸如雨滴等小物体的错误信号。 几个相邻的水平区域也必须显示移动以激活报警。
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公开(公告)号：US4218698A
公开(公告)日：1980-08-19
申请号：US24151
申请日：1979-03-06
申请人： Theodor E. Bart , Ronald A. Mills
发明人： Theodor E. Bart , Ronald A. Mills
摘要： A system employed in a television receiver for decoding and displaying graphics information such as may be encoded on a broadcast video signal. The system includes a graphics signal decoder supplied with the encoded video signal, and a plurality of transmission gates responsive to logic control signals derived from outputs of the decoder. The gates are coupled to inputs of video output stages in the receiver, and operate in response to the control signals for interrupting normal video signals to the video output stages and for enabling a voltage representative of a graphics display intensity level to be coupled to the video output stages when graphics information is to be displayed.The system also includes a graphics level control network. The level control network limits excessive graphics representative beam current levels to prevent image defocusing and kinescope screen burn. The level control network also adjusts the graphics display intensity level in accordance with the level of image representative video signals in a mixed video plus graphics display mode, to preserve a desired contrast relationship between the displayed video and graphics information.
摘要翻译： 一种用于电视接收机中用于解码和显示诸如可以在广播视频信号上编码的图形信息的系统。 该系统包括提供有编码视频信号的图形信号解码器，以及响应于从解码器的输出导出的逻辑控制信号的多个传输门。 栅极耦合到接收器中的视频输出级的输入，并且响应于用于中断到视频输出级的正常视频信号的控制信号而工作，并且使得能够将表示图形显示强度级的电压耦合到视频 当显示图形信息时的输出阶段。系统还包括图形级控制网络。 电平控制网络限制了过多的图形代表光束电流水平，以防止图像散焦和显像管屏幕烧伤。 电平控制网络还根据混合视频加图形显示模式中的图像代表性视频信号的电平来调整图形显示强度水平，以保持所显示的视频和图形信息之间的期望的对比度关系。
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