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静止图象广播是用帧时分复用的方法把50路由静止画面和伴音组成的节目合成一路静止图象广播信号,利用一个专用频道发送,并可与普通广播电视兼容.静止图象广播的接收设备包括一部普通的彩色电视接收机和一个附加器.收看时首先用键盘输出所要看的那一路节目的编码,附加器中的自动节目选择电路就将该路节目之一帧图象信号选出并存贮于一帧图象存贮器中,在不断再生的同时,送给接收机以显示画面.当属于此节目的另一帧画面到来时,进行自动更迭.一帧图象存贮器是附加器的核心.本文所述的一帧图象存贮器即是为上述目的而研制的.该存贮器采用数学方式,以3f_(sc)=13.3MHZ的取样频率对视频信号实时取样、编码、存贮.采用线性PCM编码方式,每样值以8bits量化.存贮容量为4.26Mbits.存贮体由256块动态RAM构成.重要的是本文给出了一种解决不断重复读出同一帧图象信号时,恢复PAL制彩色副载波相位连续性和逐行倒相次序连续性的方法,并为本一帧图象存贮器设计所采用.与其它方法相比,这种方法具有电路结构大,简化的优点.所研制的一帧图象存贮器已用在附加器中,功能正常,运行良好.
Still picture broadcasting uses the frame time division multiplexing method to synthesize a program of 50 still pictures and accompanying sound into a still picture broadcasting signal which is transmitted using a dedicated channel and is compatible with a normal broadcasting television. The device includes an ordinary color television receiver and an add-on.When viewing it, the code of the program to be viewed is first output by the keyboard and the automatic program selection circuit in the adder selects one of the frame image signals of the program Out and stored in a frame of image memory, constantly regenerated at the same time, sent to the receiver to display the screen when the program belonging to another frame arrives, the automatic duplication of a frame of image storage Is the core of the adder .A frame of image memory described herein is developed for the above purpose. This memory is mathematically modeled at a sampling frequency of 3 f sc (sc) = 13.3 MHz in real time Sampling, encoding, storage. Linear PCM encoding, each sample with 8bits quantization. Storage capacity of 4.26Mbits. Memory consists of 256 dynamic RAM. It is important that this article gives a solution to repeat the reading Out the same frame Image signals, the method of restoring the phase continuity of PAL color subcarriers and the sequential order of line-by-line inversion is adopted and designed for the image memory design of the present frame. Compared with other methods, this method has a circuit Large structure, simplified advantages. Developed a frame of image memory has been used in the appendage, the function is normal and works well.