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公开(公告)号：US5841482A
公开(公告)日：1998-11-24
申请号：US768361
申请日：1996-12-16
CPC分类号： G09G5/12 , H03K5/133 , H03L7/00 , H04N5/04 , H04N5/126 , G09G2340/125 , H04N5/4401 , H04N9/641
摘要： A synchronization system aligns video signals without the use of a phase locked loop. One embodiment includes a delay line and a selection circuit. A clock signal with a desired frequency for a pixel clock is applied to the delay line to generate a series of delayed signals at taps on the delay line. When a transition in a horizontal sync signal occurs, the selection circuit senses delayed signals and selects a delayed signal having a transition aligned relative to the transition in the horizontal sync signal. This delayed signal is a pixel clock signal which is not subject to frequency fluctuation of a phase locked loop. Selecting a new delayed signal at each horizontal blanking period keeps the pixel clock for each line of video aligned to the horizontal sync signal.
摘要翻译： 同步系统对齐视频信号而不使用锁相环。 一个实施例包括延迟线和选择电路。 具有用于像素时钟的期望频率的时钟信号被施加到延迟线，以在延迟线上的抽头处产生一系列延迟信号。 当水平同步信号发生转换时，选择电路感测延迟的信号，并选择相对于水平同步信号中的跃迁具有对准的延迟信号。 该延迟信号是不受锁相环的频率波动影响的像素时钟信号。 在每个水平消隐期间选择一个新的延迟信号可以使每行视频的像素时钟与水平同步信号对齐。
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公开(公告)号：US5644333A
公开(公告)日：1997-07-01
申请号：US354190
申请日：1994-12-12
CPC分类号： G09G5/395 , G09G5/14 , H04N9/75 , G09G2340/12
摘要： This method is most advantageous when an analog multiplexer is controlled to pass either analog graphics signals or analog motion video signals to a multimedia display screen. In the preferred embodiment, this method includes the steps of outputting a digital color key from a graphics memory buffer at a designated time and for a designated period and then converting this color key to an analog signal. This analog color key signal is then detected during this designated period and stored to obtain a stored color key value. The graphics memory is then controlled to output the graphics signals to be displayed on a multimedia screen. These graphics signals include a digital color key for controlling a multiplexer to display a motion video window on the multimedia screen in place of the color key. The outputted graphics signals are converted into analog signals, and these analog signals are compared to the stored color key value for detecting whether a color key is being outputted in the graphics data stream. When the analog graphics signal matches the stored color key value, the multiplexer is controlled to pass motion video signals to the multimedia screen for displaying a video window within a graphics display. By using this method, the detection of a color key is not affected by any drifts in the analog graphics signal.
摘要翻译： 当模拟多路复用器被控制以将模拟图形信号或模拟运动视频信号传递到多媒体显示屏幕时，该方法是最有利的。 在优选实施例中，该方法包括以下步骤：在指定时间和指定时段从图形存储器缓冲器输出数字彩色键，然后将该色键转换为模拟信号。 然后在该指定期间检测该模拟彩色键信号，并存储以得到存储的色键值。 然后控制图形存储器以输出要在多媒体屏幕上显示的图形信号。 这些图形信号包括用于控制多路复用器以代替彩色键在多媒体屏幕上显示运动视频窗口的数字彩色键。 将输出的图形信号转换为模拟信号，将这些模拟信号与存储的色键值进行比较，以检测图形数据流中是否输出彩色键。 当模拟图形信号与存储的颜色键值匹配时，控制多路复用器将运动视频信号传递到多媒体屏幕，以在图形显示内显示视频窗口。 通过使用这种方法，颜色键的检测不受模拟图形信号中任何漂移的影响。
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公开(公告)号：US5696527A
公开(公告)日：1997-12-09
申请号：US354187
申请日：1994-12-12
申请人： Sherman T. King , Tommy C. Lee , Niantsu Wang , Yen-Fah Chu , Scott A. Kimura , Guorjuh T. Hwang
发明人： Sherman T. King , Tommy C. Lee , Niantsu Wang , Yen-Fah Chu , Scott A. Kimura , Guorjuh T. Hwang
CPC分类号： G09G5/14 , G09G5/395 , H04N9/75 , G09G2340/12
摘要： In the preferred embodiment, the RGB analog signals generated by a VGA card in a personal computer are applied to a first input of an analog multiplexer. The digital video data stored in a video memory buffer on a video card is converted to RGB analog signals using a D/A converter, and these analog signals are applied to a second input of the analog multiplexer. An analog comparator compares a preselected color key to the analog output of the VGA card. When there is a match, the analog comparator controls the multiplexer to pass the analog video data to the monitor for display. When the color key is not detected, the data from the VGA card is transmitted to the monitor for display. Other features for improving the video overlay precision and the quality of the displayed image are also described.
摘要翻译： 在优选实施例中，由个人计算机中的VGA卡产生的RGB模拟信号被施加到模拟多路复用器的第一输入端。 存储在视频卡上的视频存储器缓冲器中的数字视频数据使用D / A转换器转换成RGB模拟信号，并将这些模拟信号加到模拟多路复用器的第二输入端。 模拟比较器将预选色键与VGA卡的模拟输出进行比较。 当有匹配时，模拟比较器控制多路复用器将模拟视频数据传送到监视器进行显示。 当未检测到颜色键时，来自VGA卡的数据被传送到监视器进行显示。 还描述了用于提高视频重叠精度和显示图像的质量的其他特征。
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公开(公告)号：US5644325A
公开(公告)日：1997-07-01
申请号：US354296
申请日：1994-12-12
申请人： Sherman T. King , Niantsu Wang , Guorjuh T. Hwang
发明人： Sherman T. King , Niantsu Wang , Guorjuh T. Hwang
CPC分类号： G09G5/14 , G09G5/395 , H04N9/75 , G09G2340/12
摘要： A digital to analog converter is described for a multimedia system in which the magnitude of the analog output is controlled by signals applied to level select inputs of the digital to analog converter. Digital signals to be converted to an analog output are connected to a different set of inputs. This converter is advantageous for use in a display system where the brightness of the display may be independently controlled by the signals applied to the level select inputs. In this way, the digital information signals to be converted to an analog signal need not be modified to increase or decrease the brightness of the display.
摘要翻译： 描述了一种用于多媒体系统的数模转换器，其中模拟输出的幅度由施加到数模转换器的电平选择输入的信号控制。 要转换为模拟输出的数字信号连接到不同的输入集合。 该转换器有利于在显示系统中使用，其中显示器的亮度可以被施加到电平选择输入的信号独立地控制。 以这种方式，不需要修改要转换为模拟信号的数字信息信号，以增加或减少显示器的亮度。
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