Interface for operating a dot matrix printer for printing a video image
    1.
    发明授权
    Interface for operating a dot matrix printer for printing a video image 失效
    用于操作点阵打印机以打印视频图像的接口

    公开(公告)号:US4394685A

    公开(公告)日:1983-07-19

    申请号:US184079

    申请日:1980-09-04

    摘要: An electronic interface for operating a dot matrix printer to print a pattern appearing on a television screen employs video-type signals incorporating field and line sync signals, digitized image signals representative of dots of information along each raster line and dot pulses for synchronizing the digitized image signals. Upon receipt of a print request, a line address counter is incremented by each line sync pulse. A second counter, which is incremented each time the line address counter reaches a maximum count, has its count set into a horizontal position counter at the beginning of each line scan and is decremented synchronously with the dot pulses. The sequentially received dot information is loaded serially into a shift register and is transferred byte-wise in parallel into a location in a random access memory identified by the count in the line address counter when the horizontal position counter reaches a zero count. When the line address counter reaches its maximum count, the interface circuitry prints the stored bytes, representing a "slice" of the raster image in an orientation transverse to the direction of the lines comprising the raster image. Successive "slices" are acquired and printed in a similar fashion to collectively create a completed image.

    摘要翻译: 用于操作点阵打印机以打印出现在电视屏幕上的图案的电子接口使用包含场和行同步信号的视频类型信号,表示沿着每条光栅线的信息点的数字化图像信号和用于使数字化图像同步的点脉冲 信号。 在接收到打印请求时,行地址计数器由每行行同步脉冲递增。 每次线路地址计数器达到最大计数时递增的第二个计数器在每行扫描开始时将其计数设置为水平位置计数器,并与点脉冲同步递减。 顺序接收的点信息被串行地加载到移位寄存器中,并且当水平位置计数器达到零计数时,被逐行地并行地传送到由行地址计数器中的计数所标识的随机存取存储器中的位置。 当行地址计数器达到其最大计数时,接口电路以横向于包括光栅图像的线的方向的方向打印存储的字节,表示光栅图像的“切片”。 以相似的方式获取和打印连续的“切片”以共同创建完成的图像。