摘要 |
An alignable electronic background grid generation system, for use with a raster-type video graphics display unit on which graphic data is displayed, includes a horizontal grid line generator and a vertical grid pattern controller. An appropriate control device supplies to these components background grid parameter data including line spacing, line intensity pattern, and line offsets. Utilizing this data, the generator produces, in synchronism with horizontal video scanning of the display unit, grid intensity control signals indicating the requisite intensity of background grid spots at corresponding picture elements in the resultant display. These intensity control signals are modified in response to the output of the vertical grid pattern controller, which itself is synchronized to the vertical line clock of the video graphics display unit. The supplied grid parameter data can be altered as the location or size of the displayed graphic data is changed, so that the resultant background grid will remain aligned with the displayed graphic data.
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